GI Dinosaurs Hadrosaur Tail Bone Vertebra 2007 10 Dinosaurs Skin... · 2011-11-23 · Hadrosaurs...

Revised: October 3, 2007 Page1of2

Royal Ontario MuseumDepartment of Museum Volunteers

Gallery Interpreters

Information Sheet

Hadrosaur Tail Bone VertebraHadrosaur Toe

Hadrosaur DentitionHadrosaur Tooth

Albertosaurus Tooth & ClawDinosaur Skin

Handling Instructions

Caution Level: DurableGI Handling: Naked HandVisitor Handling: Naked HandPackaging: Some in Plastic Boxes – Others just in the DrawersTransporting: Carry Bag RequiredReal or Reproduction: Real (Hadrosaur Vertebra, Dentition and Tooth) and Reproduction (Hadrosaur

Toe, Albertosaurus Tooth and Claw, Dinosaur Skin)

1. Hadrosaur Tail Bone Vertebra

The vertebra is from a duck-billed dinosaur from Alberta. It is about 65 million years old. It wasprobably collected in the 1930s by a ROM expedition to the Red Deer region. It was an isolatedfind, from the surface, and was not associated specifically with any other bones.

On one side there is a groove where the spinal column went through; there would have been aboney arch over it to protect the column. This arch has been broken off. Out of interest, aspecialized expert could tell whether the arch had been broken off before or after fossilization ofthe vertebra by the way the break had occurred.

On the other side are four bumps; the two larger ones were towards the head of the animal. Weknow that this is a tail bone because of the two holes in the bigger bumps. These were thelocation of a pair of chevron bones (V-shaped), and only the tail vertebra had bones exactly likethis.

The bone looks very much as it might have in real life, only it would probably have been creamierin colour. It is fairly heavy due to mineral impregnation: as it was lying in sediments, mineralsbecame deposited in the bone. The roughness at the end could be due to weather erosion afterthe bone came out of the rock it was in.

Revised: October 3, 2007 Page2of2

2. Hadrosaur Toe

The toe is from a duck-billed dinosaur from Alberta. It is about 65 million years old. It wasprobably collected in the 1930s by a ROM expedition to the Red Deer region. It was an isolatedfind, from the surface, and was not associated specifically with any other bones.

It is from a front hand or foot.

3. Hadrosaur Dentition

The dentition (jaw and teeth) is from a duck-billed dinosaur from Alberta. It is about 65 millionyears old. It was probably collected in the 1930s by a ROM expedition to the Red Deer region.

It shows the rows or batteries of teeth in the mouth. Wear from grinding is evident.

4. Hadrosaur Tooth

One single hadrosaur tooth is available, in a sealed jar. It is not normally used since it is so small,and easily stolen. It can be used under careful supervision. It is about 65 million years old.

5. Albertosaurus Tooth and Claw

In regular use, there is a tooth and claw available. Both of these are reproductions in plaster. Theoriginals are in the collection. They do not necessarily belong to the Albertosaurus on display, butare similar to what is displayed. The originals are about 75 million years old.

6. Dinosaur Skin

The specimen available is a reproduction of a skin mould fossil. It illustrates the texture. Thecolour is a best guess ONLY. ROM scientists believe that skin was likely an earth tone to blendwith the environment.

It is believed that dinosaur skin did not change much over many millions of years. The cast canbe used to illustrate skin in either the Jurassic or Cretaceous time periods.

Revised: January 27, 2006 Page1of2



Dinosaur Specimens


Revised: February 2, 2006 Page1of1



Dinosaur Skin

10 + Questions

1. What is this? A fossil.

2. Why is it so light? A plaster copy. A real fossil is heavy - as itfossilized, organic material was replaced withinorganic minerals.

3. Is this a fossil like a dinosaur bone? No, it=s a fossilized impression.

4. What part of a dinosaur=s body? Skin.

5. What did this dinosaur eat? Can=t tell - could be from a planteater or ameateater.

6. What=s the general word for a planteater? Herbivore.

7. For a meateater? Carnivore.

8. What are humans? Omnivores.

9. What modern type of animal has skin the same? Reptiles.

10. Is this the real colour? No - a guess by scientists - no actual skin hassurvived.

Revised: November 19, 2007 Page 1 of 2


Museum Guides/Gallery Interpreters

The Age of Dinosaurs Gallery

Hadrosaurs

General Information

Data Sheet

1. What is a Hadrosaur?

A member of the family Hadrosauridae – Hadrosaur means “bulky or heavy lizard”. Barosaurusalso means “heavy lizard”. Hadrosaurs were found before any of the large sauropods, likeBarosaurus, and that name stuck, even though MUCH heavier dinosaurs were found later.

A member of the order Ornithischia – bird-hipped – term is derived from the Greek ornitheos(ορνιθειος) meaning 'of a bird' and ischion (ισχιον) meaning 'hip joint'.

Often called a duck-bill or duck-billed dinosaur. A plant-eater or herbivore. Were common herbivores in what are now Asia, Europe and North America. Lived during the Upper Cretaceous Period, roughly 76 to 65 million years ago, toward the end of

the Mesozoic, the Age of Dinosaurs. A huge, mass extinction killed the dinosaurs 65 millionyears ago

Are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs (likeCamptosaurus) and had similar body layout.

First dinosaur family to be identified in North America, the first traces being found in 1855 – 1856with the discovery of fossil teeth. A first “complete” hadrosaur specimen was found in the 1850’sin New Jersey, USA.

Divided into two subfamilies: Lambeosaurines (Lambeosaurinae) have large, hollow cranial crests or tubes, and are less

bulky. Hadrosaurines (Hadrosaurinae) lack the cranial crests or tubes and are larger.

For the Lambeosaurines, the nostrils went up through the crest. There are several theories – thecrest may have been used as a resonating chamber to make/amplify sounds/calls, for courtshipdisplays, for species recognition, and/or as a sense-of-smell enhancer. Recent researchsuggests that these crests did not enhance the sense of smell. Babies had no crest – skull shapechanged with age – the nasal bones in the skull expanded to form the tall hollow crest in theadult. Theories that males may have had larger crests than females may not be valid.

Known as the duck-billed dinosaurs due to the similarity of their head to that of modern ducks. Insome species, the whole front of the skull was flat and broadened out to form a toothless beak,ideal for clipping leaves and twigs. However, the back of the mouth contained literally hundredsof small, leaf-shaped teeth, arranged in rows or batteries, suitable for grinding food before it wasswallowed. Hadrosaurs, like their iguanodontian cousins, had a rudimentary dental specialization


analogous to incisors and molars. This has been hypothesized to have been a crucial factor inthe success of this group in the Cretaceous Period. Teeth were continually replaced.

Ranged in size from 10 – 40 feet (3 to 12 m) in length. Had skin with a pebbly texture. Were herding animals, at least in some species. No natural defenses. Walked on four legs. Could not achieve a full gallop, rather more of a brisk walk. Could likely

stand and move on hindlegs for a brief time. Have appeared in many movies – especially notable for appearances in the Jurassic Park

movies. ROM’s collection of Hadrosaurs is the best available in one place!! The collection contains

embryos, eggs, skulls, and complete skeletons from juveniles to adults, permitting the study ofthe evolution of growth from hatching to adult. There are 7 complete skeletons, 9 skulls – over60% of the hadrosaurs known in North America are represented and displayed.

The ROM’s crested lambeosaurines are the BEST in the world.

Revised: November 19, 2007 Page1of2

Royal Ontario MuseumDepartment of Museum VolunteersMuseum Guides/Gallery Interpreters

The Age of Dinosaurs

Hadrosaurs – Background Information

Data Sheet

The family Hadrosauridae is one of large herbivores, commonly called 'duck-billed' hadrosaurs. Theyevolved from an iguanodont ancestor (such as Camptosaurus) and diversified rapidly in the LateCretaceous into a variety of forms notable for their often bizarre skull shapes. The hadrosaurs' handswere webbed, yet the rapidly replaceable teeth, inflexible tail, strong bones and sturdy posture imply thatthey were mostly land animals that fed on terrestrial vegetation - but lived close to bodies of water.

The Head and Crest

The head is the most fascinating characteristic in this Order. In Parasaurolophus, a 'U' shaped tube like atrombone slide fills a huge, backward-pointing cylindrical projection, while in Corythosurus, andLambeosaurus, a semi-circular crest of varying size is filled with a convoluted tube.

The function of the crest remains somewhat mysterious. It could be that air blown out through the nostrilsresonated in the tubes; this would have generated terrific roars and bellows. The crests may also haveenlarged the sensory area of the nose, giving a highly acute sense of smell – however, recent researchsuggests that this is not the case. Suggestions that these structures acted as air-tanks for use in sub-aquatic feeding have long been dismissed. Other theories abound – crests may have had a role incourtship displays, or in species recognition.

Some, such as the flat-headed hadrosaurs, had no crests at all, but had enlarged nasal compartmentswhich could have supported an inflatable sack of skin like that seen on an elephant seal. This could alsohave been filled with air to deliver a powerful roar, and may also have been brightly colored for displaypurposes.

The Beak

While some hadrosaurs seem to have a broad and superficially duck-like bill at the front of the mouth, theappearance is deceptive. Rather than forming a broad, flat beak adapted for 'dabbling' as ducks do, thebones of the beak are strongly attached to the skull, and have a sharp, notched margin. Comparing thisto modern animals, the nearest similarity is to tortoises and turtles rather than dabbling birds; turtles havean extremely strong, self-sharpening beak useful for cutting plants and flesh alike.

The Teeth

Further back in the jaw are the teeth. While each individual tooth seemed small and feetble, when put intheir correct places in the jaw, they combined to form one of the most incredible plant-crushing andgrinding arrangements known in the animal kingdom. In each jaw, hundreds of teeth can be seen. Eachone appears as a small diamond-shaped shield, locked in against its neighbours by bony cement to form


what is called a 'battery' or 'magazine' of teeth. They wore down from the top to form a broad, roughpavement which acted like a millstone for grinding the toughest of plant food. Generally, the teeth arearranged into as much as fifty columns per battery, with as many as six per column – one on top of theother – three hundred teeth per battery and four batteries altogether (two up and two down) makes agrand total of 1,200 teeth in all. That is just a general figure, some would have even more.

The Legs. Fingers, and Toes

The hadrosaurs generally had strong and well-developed forelimbs which ranged from a half to two-thirdsthe length of their hindlimbs. Their fingers extended into hooflike nails and were enclosed together in amitten of skin that formed a tough crescent-shaped pad, designed for walking. Only the outer finger hadindependent mobility. The hindlimbs were well-muscled and powerful, but proportions indicate that thehadrosurs were not built for great speed. The feet were relatively broad, with three stout toes ending inhoof-like claws. The current view is that hadrosaurs walked on four legs, and could not achieve a fullgallop, rather more of a brisk walk. They could likely stand and move on hindlegs for a brief time. All fourlimbs were needed to achieve a good balance, as the spine was very stiff, limiting the ability to change thecentre of mass. This is due to all the tendons running along the spine.

The Tail

The tails were deep and flattened on both sides. A bony lattice of rods extended down their back and withthe support of ossified tendons kept the tail straight and inflexible - it could thus be used as acounterbalance when walking.

The Skin

Because of fossil impressions, much is known about the skin of the hadrosaurs. It was not quite the sameas that of modern lizards and snakes, with their dense overlapping scales. It was more like a mosaic ofscales of varying sizes: in some places, such as across the back where they were exposed to the sun, thescales were quite large and prominent while in other, less exposed places, they were small. in manymembers of the hadrosaur family, frills ran almost the entire length of the body, while in others the skinhad rows of hornlets or rectangular serration. Loose skin would be concertinaed into large vertical foldsover the base of the neck, upper arms and shoulders.




Hadrosaur Vertebrae or Toe or Jaw/Dentition

10 + Questions


2. Why is it so heavy? As it fossilized, organic material was replacedwith inorganic minerals.

3. What part of a dinosaur=s body?

4. What did this dinosaur eat? Plants.

5. What=s the general word for a planteater? Herbivore.

6. For a meateater? Carnivore.


8. How did this animal walk? Four legs, tail straight out.

9. How might the animal run? On hind legs.

10. Why would the animal run? Meateater nearby - other danger.

11. How would the animal figure out danger? Hearing, sight, smell.

12. What is the crest for? Visual species identifier, part of nose/smellingsystem, making noises - mating calls, dangercalls.




Albertosaurus Tooth or Claw

10 + Questions


2. Why is it so light? A plaster copy. A real fossil is heavier - as itfossilized, organic material was replaced withinorganic minerals.

3. What part of a dinosaur=s body?

4. What did this dinosaur eat? Meat.

5. How can you tell? Tooth, claws are sharp.

6. Is this animal a good hunter? Yes.

7. What=s the general word for a meateater? Carnivore.

8. For a planteater? Herbivore.


10. How did this animal walk? On two hind legs.

11. Is this animal an adult? No - a juvenile.

12. Where did this dinosaur live? Alberta.

13. What other well-known dinosaur looks like this? Tyrannosaurus Rex.





Albertosaurus

Data Sheet

1. Identification of Specimens on Display

Full Name: Albertosaurus libratusBelongs to broad classification: Theropod dinosaur; SaurischianFound Where: Red Deer River, Alberta, CanadaFound When: 1933Age: Late Cretaceous Period, 70 million years oldReal?: Mostly real fossils on display

Accession #’s: 1247

2. Description

Name means “Alberta Lizard”. Also known as Gorgosaurus – there is still much debate about whether they are different species!! Adapted for running down prey and using brute force to subdue it. Had good vision and a keen sense of smell. ROM specimen is a juvenile – in human terms, about 10 years old. At full, adult size, it would be about 1.5

times larger. A carnivore (meat-eater). Had a large head with scissor-action jaws, and sharp, serrated teeth that must

have been capable of ripping through the muscles and bones of the largest prey. The structure of its jawallowed all the teeth to engage at once when biting. Teeth that may be worn out were continually replaced.The lower jaw of Albertosaurus had from 14 and 16 teeth; the upper jaw had 17-19 teeth. It had one row ofteeth in each jaw but had at least one replacement tooth growing up from under each tooth.

The bones are thin compared with hadrosaurs to cut down on weight. The clawed hands and feet wereeffective for grappling and ripping prey. The front claws may have grasped prey while the hind ones kickedand slashed – however, the function of its tiny front limbs is uncertain. Like a lion – one kill, such as a largehadrosaur, would likely last for 2-3 weeks.

Extra set of ribs is unique to Albertosaurus, and have not been found in any other species thus far. Notsure of their function but may have been protective.

Would have moved quite fast. The relative proportion of the lower leg to the upper indicates speed. Theright leg shows a break and subsequent healing.

These carnivores were agile, pursuing, leaping predators running their prey and slashing it to death. Theyneeded high metabolic rates - therefore were probably warm-blooded.

Close relative of the Tyrannosaurus rex, but much smaller. The discovery of 22 individuals at one site provides evidence of pack behavior. About 30 feet (9 m) long, about 11 feet (3.4 m) tall at the hips, and may have weighed up to 3 tons.


3. Information

Lived during the late Cretaceous period, roughly 83 to 65 million years ago, toward the end of theMesozoic, the Age of Dinosaurs. A huge, mass extinction killed the dinosaurs 65 million years ago.

Among the contemporaries of Albertosaurus in North America were Lambeosaurus, Nanotyrannus,Parasaurolophus, Corythosaurus, Euoplocephalus, Kritosaurus, Tyrannosaurus rex, Triceratops, andPachyrhinosaurus.

Named by Henry Fairfield Osborn in 1905. Fossils have been found in North America, including the western USA, and Alberta, Canada. Had skin with a pebbly texture. Current mount is a more natural posture, with a horizontal spine.





Allosaurus

Data Sheet


Full Name: Allosaurus fragilisBelongs to broad classification: Theropod dinosaur; SaurischianFound Where: Dinosaur National Monument and Cleveland-Lloyd Quarry, both in Utah,

USAFound When: Unknown – early 1900’sAge: Late Jurassic Period, about 150 million years oldReal?: Mostly real fossils on display; composite constructed from the fossilized

bones of many individuals

Accession #: 12868

2. Description

Name means “strange or different lizard”, as its vertebrae were different from other dinosaurs known at thetime of its discovery.

Adapted for ambushing prey and using brute force to subdue it. Had good vision and a keen sense of smell. A carnivore (meat-eater). Had a large head with scissor-action jaws, and sharp, serrated teeth that must

have been capable of ripping through the muscles and bones of the largest prey. The structure of its jawallowed all the teeth to engage at once when biting. Teeth that may be worn out were continually replaced.The lower jaw of Allosaurus had from 14 and 17 teeth; the upper jaw had 17-19 teeth. It had one row ofteeth in each jaw but had at least one replacement tooth growing up from under each tooth.

The clawed hands and feet were effective for grappling and ripping prey. The front claws may havegrasped prey while the hind ones kicked and slashed. Like a lion – one kill, such as a large Stegosaurus,would likely last for 2-3 weeks.

Would have moved reasonably fast. The relative proportion of the lower leg to the upper indicates somespeed. However, not as fast as its descendants. Most likely it ambushed prey as opposed to running itdown.

These carnivores were agile predators attacking their prey and slashing it to death. They needed highmetabolic rates - therefore were probably warm-blooded.

Ancestor of the Tyrannosaurus rex and Albertosaurus. Averaged about 30 feet (9 m) long, and may have weighed up to 2.5 tons.

3. Information

A complete cast was made from the real fossils – this cast skeleton used to be displayed in a previousGallery, but is now in storage.


Among the contemporaries of Allosaurus in North America were Stegosaurus, Camptosaurus, Apatosaurus(formerly known as Brontosaurus), Diplodocus, Camarasaurus, Ceratosaurus, Brachiosaurus,Lesothosaurus, and Compsognathus.

Described in 1877 by Othniel Charles Marsh, although Allosaurus has had several other names over time. Fossils have been found in North America, including Colorado, Utah and Montana, USA, and Portugal. Allosaurus is the official state dinosaur of Utah. Almost as popular as T. rex in popular culture – very popular at museums; has appeared in many films. It

is top predator in both Arthur Conan Doyle's 1912 novel, The Lost World, and the 1925 film adaptation, thefirst full-length motion picture to feature dinosaurs (it is not to be confused with Tyrannosaurus, which alsoappears in the film). It later became the starring dinosaur of the 1956 film The Beast of Hollow Mountain,and the 1969 film The Valley of Gwangi, two genre combinations of living dinosaurs with Westerns.Allosaurus appears in the second and fifth episodes of the BBC television series Walking with Dinosaurs.

Had skin with a pebbly texture.



Docents/Gallery Interpreters


Barosaurus

Data Sheet

1. Identification of Specimen on Display

Scientific Name: Barosaurus lentusCommonly called a: DiplodocidCommon Name: Sauropod dinosaurKingdom: AnimaliaPhylum: ChordataClass: ReptiliaSuperorder: DinosauriaOrder: SaurischiaFamily: DiplodocidaeFound Where: Morrison Formation, Dinosaur National Monument, Utah, USAFound When: 1910-1920Age: Late Jurassic Period, 150 million years oldReal?: Mix of real and cast – more real than cast; most real are in the central

area – all femurs, one lower leg, and many of the larger vertebrae.Accession #: 03670


2. Description

Name means "Heavy Lizard" referring to its heavy neckbones. Note that “hadrosaur” also means “heavylizard” – hadrosaurs were found before any of the large sauropods, and the name stuck, even thoughMUCH heavier dinosaurs were found later.

Closely related to the better known Diplodocus, but had much taller vertebrae, a shorter tail, and a muchlonger neck.

Large, plant-eating (herbivore) dinosaur. Barosaurus individuals could be from 66-98 feet (20 – 30 m) long, and may have weighed between 12 – 20

metric tonnes (12,000 – 20,000 kilos; 13.2 – 22 short tons). Four-fifths of its total length was neck and tail.ROM specimen is 90 feet (27.4 m) and would have weighed 12-13 metric tonnes (12,000-13,000 kilos;13.2-14.3 short tons).

Head thought to have been small, but no head has ever been found – head on display (and some othermissing pieces) is cast from a Diplodocus, which was almost identical except that Barosaurus had neckvertebrae that were larger and heavier.

There are theories that, like a giraffe, it had arterial valves in the neck, so that blood could pump up theneck, but preventing most of the blood from falling back down. Not supported by ROM scientists. Likelykept the neck horizontal as a usual posture.

Neck is about 1/3 of the body length. Some vertebrae are 1 m long. Their shape and fit means that the head and neck could easily move

sideways, but did not reach up easily. Backbone between shoulders and hips is designed to bear the great weight of the neck, tail and belly – the

muscles for this were attached to the upward spines of the vertebrae. Femur or thigh bone about 8 feet (2.5 m) long – bigger than most human beings!! Would have moved very slowly. Walked on four legs. Tail would not have stretched out stiffly. Would have been limp like a rope, and might have been used in

defence in a whiplash manner. Primary defence against predators was its sheer size. Note the superb armature, and the way that the fossil bones are mounted as compared to cast ones. Real

bones have much more support, all external, and can be removed individually for study.

3. Information

Only six of these dinosaurs have been found so far. This is the second most complete specimen. Only sauropod skeleton consisting largely of real fossil bone mounted in Canada, as well as the largest

dinosaur skeleton on display in the country. It is the only 'real' Barosaurus mounted in a life pose in theworld – The American Museum of Natural History has a cast skeleton mounted, and a vertebral column in aglass floor.

Named by Othniel Charles March in 1890. Collected for the Carnegie Museum by Earl Douglas in 1914. Fossils have been found in South Dakota and Utah, USA. Had skin with a pebbly texture. The life span is not known but certainly over 20 years and perhaps close to 50. Acquired by the ROM in 1962 through a trade organized by former ROM Curator Dr. Gordon Edmund

(some ROM hadrosaur specimens were traded to the Carnegie Museum). Stegosaurus was acquired aspart of the same trade. Barosaurus was never installed in the 1970’s gallery as this specimen was too big.Over time, the fossils from this one individual were separated and stored in different locations. Eventually,it was forgotten that a fairly complete specimen was in the Collection. One femur was displayedperiodically, but misidentified as a Diplodocus. When the records of the Collection were automated, thisone did NOT make into the database. “Re-discovered” in 2007, as Associate Curator Dr. David Evans wassearching to acquire a large sauropod (on the Great Sauropod Goose Chase!!). Dr. Evans read a recentlypublished article referring to the Barosuarus in the ROM’s collection. He then found a 1968 archival letterfrom Jack McIntosh that identified the traded bones as Barosaurus. Over 40% of the Barosaurus wasfound scattered throughout the storage locations. Turns out even the ROM has skeletons in the closet!!Dr. Evans arranged for the Carnegie Museum to ship five neck vertebrae that had not been shipped in1962. He arranged to have everything prepared and mounted for the current Gallery. Three of theretrieved neck vertebrae were mounted; one is being prepared and will be displayed in a nearby case).

Nicknamed “Gordo” in honour of Dr. Edmund. “Gordo” also means “fat” in Spanish, a valid description foran animal of this size!!


Sauropods include the largest animals ever to walk on land. This group includes well-known familymembers such as Apatosaurus, Brachiosaurus, and Diplodocus. They first appeared in the early JurassicPeriod, but were most abundant during the late Jurassic. In South America, Europe and India, theyremained as important herbivores during the Cretaceous Period.

Among the contemporaries of Barosaurus in North America were Stegosaurus, Allosaurus, Camptosaurus,Apatosaurus (formerly known as Brontosaurus), Diplodocus, Camarasaurus, Ceratosaurus, Brachiosaurus,Lesothosaurus, and Compsognathus.

Sauropods were lizard-hipped, like Theropods (meat-eating dinosaurs) and birds. Largest sauropods reached 30 m (98 feet) in length, and weighed over 50 metric tonnes (55 short tons).

Sauropods of the Titanosaur type were much larger than Barosaurus and its near relatives. The recent findin Argentina, based on a very few bones, would make it the largest at about 70 metric tonnes!!

Sauropods needed only about 1/10 of the calories that a similar sized mammal would require. Bacterialaction in the gut would help digest food. There is no evidence to confirm the presence of gastroliths asfound in other herbivores like Stegosaurus.

Two African species of Barosaurus have been identified, but there is still much debate as to whether theseare a different genus completely – Tornieria.

A huge, mass extinction killed the dinosaurs 65 million years ago.

Note the cast of the baby Sauropod from a different find but from the same Morrison Formation. Babies hatchedfrom round eggs. Eggs ranged in size from that of an ostrich egg to a volleyball. Babies grew to adult size in under20 years. Female probably laid between 20-30 eggs. The exact genus of a baby cannot be identified. Until thebabies reached maturity, with full-grown neck and tail, it was impossible to determine exact genus.

Sources:

ROM WebsiteThe writings of Renee Bozowsky, based on conversations with Dr. David Evans in 2008.Wikipedia

Revised: August 15, 2011 Page 1 of 1


Touring Section

Information Sheet

Apatosaurus Versus Brontosaurus

Brontosaurus is the former name of the dinosaur Apatosaurus. The confusion arose in 1874 after a scientist, O.C.Marsh, unearthed some fossils in Wyoming, USA, and believed that he had discovered a new genus of dinosaur,which he named Brontosaurus. Later, evidence proved that the fossils were those of a dinosaur already discoveredand named, the Apatosaurus. In 1974 the name Brontosaurus was formally discarded. Apatosaurus means‘deceptive lizard’. Brontosaurus means ‘thunder lizard’.

There is an apatosaurus thigh (femur) bone on display in the Age of Dinosaurs Gallery near the Barosaurus.

Apatosaurus louisae; Sauropod dinosaur, Ornithischian; femur; Utah, USA; Late Jurassic, 150 million years old;Accession # 55016.

The apatosaurus was not the longest sauropod; however its skeleton was extremely sturdy, as this massive femur(thigh bone) shows.

Apatosaurus was a giant plant-eating sauropod dinosaur, one of the largest land animals of all time. It livedbetween 147 million and 137 million years ago during the Late Jurassic and Early Cretaceous periods. Its fossilremains are found in North America and Europe. Apatosaurus weighed as much as 30 tons and measured up to21 metres (70 feet) long, including its long neck and tail. It had four massive and pillar-like legs, and its tail wasextremely long and whip-like.





Camptosaurus

Data Sheet


Full Name: Camptosaurus disparBelongs to broad classification: Ornithischian (bird-hipped) dinosaurFound Where: Dinosaur National Monument and Cleveland-Lloyd Quarry, both in Utah,


bones of many individuals; head is a best guess (none found so far)

Accession #: 5090

2. Description

Name means “ bent lizard”, because, when standing on all fours, its body must have been arched. A herbivore (plant-eater). No head has ever been found. Speculation is that it had a horny beak, that there were a small number of

teeth which replaced themselves constantly, and that teeth were small and blunt for grinding. Could walk on 2 or 4 legs. Quick and agile – probably ran on 2 hind legs. May have lived in herds. Averaged about 26 feet (7.9 m) long, 6.7 feet (2 m) in height at the hips, and may have weighed up to 2

tons. Believed to be the ancestor of the hadrosaurs.

3. Information

Among the contemporaries of Camptosaurus in North America were Allosaurus, Stegosaurus, Apatosaurus(formerly known as Brontosaurus), Diplodocus, Camarasaurus, Ceratosaurus, Brachiosaurus,Lesothosaurus, and Compsognathus.

Described in 1879 by Othniel Charles Marsh as Camptonotus – renamed in 1885 as a cricket already hadthis name!!

Fossils have been found in North America, including Colorado, Utah and Montana, USA, and in Europe. Had skin with a pebbly texture.




Museum Guides


Hadrosaurs

Corythosaurus

Data Sheet


Full Name: Corythosaurus casuariusCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Lambeosaurines (hollow fan-shaped or tubular skull crest)Found Where: Red Deer River, Alberta, CanadaFound When: Early 1900’sAge: Late Cretaceous Period, 70 million years oldReal?: Mostly real fossils on display

Accession #’s: 845 – more or less full skeleton, found 1919759 and 870 – juvenile skulls871 – skull

2. Description

Large, plant-eating, duckbill dinosaur (family Hadrosauridae). About 30-33 feet (9-10 m) long, 6.6 feet (2 m) tall at the hips, and may have weighed up to 5 tons. Had a hollow, bony crest on top of its long head in the shape of a helmet flattened on the sides

(Corythosaurus means "helmet lizard"). For the Lambeosaurines, the nostrils went up through the crest. There are several theories – the

crest may have been used as a resonating chamber to make/amplify sounds/calls, for courtshipdisplays, for species recognition, and/or as a sense-of-smell enhancer. Recent researchsuggests that these crests did not enhance the sense of smell. Babies had no crest – skull shapechanged with age – the nasal bones in the skull expanded to form the tall hollow crest in theadult. Theories that males may have had larger crests than females may not be valid.

Had a toothless beak and hundreds of cheek teeth, arranged in rows or batteries, that it used togrind up its food.

Walked on four legs. Could not achieve a full gallop, rather more of a brisk walk. Could likelystand and move on hindlegs for a brief time.

No natural defenses. Was a herding animal.


Perhaps ate pine needles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves.

3. Information

Lived during the late Cretaceous period, roughly 80 to 65 million years ago, toward the end of theMesozoic, the Age of Dinosaurs. A huge, mass extinction killed the dinosaurs 65 million yearsago.

Among the contemporaries of Corythosaurus in Canada were Albertosaurus, Nanotyrannus,Parasaurolophus, Edmontosaurus, Lambeosaurus, Euoplocephalus, Kritosaurus, andPachyrhinosaurus.

Named by Barnum Brown in 1914. Fossils have been found in North America, including Montana, USA, and Alberta, Canada. Fossilized skin with a pebbly texture was also found. A herd of Corythosaurs is featured in the film Jurassic Park III. For many years, the ROM skeleton was mounted as shown below – an unnatural posture. More

recent scholarship confirmed that this was incorrect – the current mount is a natural posture.

Revised: January 15, 2008 Page 1 of 2



The Age of Dinosaurs Gallery and the Currelly Gallery

Hadrosaurs

Edmontosaurus

Data Sheet


Full Name: Edmontosaurus annectensCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Hadrosaurines (flat skull with no crest)Found Where: Red Deer River, Alberta, CanadaFound When: 1924 – full skeleton in Currelly Gallery

1934 – adult skull in Age of Dinosaurs Gallery near MaiasauraAge: Late Cretaceous Period, 70 million years oldReal?: Yes

Accession #: 867 – full skeleton801 – adult skull

2. Description

Name means “Edmonton lizard”, named for the Edmonton Rock Formation (now called theHorseshoe Canyon Formation), near Edmonton, Alberta.

Large, plant-eating, duckbill dinosaur (family Hadrosauridae). Skull (Accession # 801) must have come from an unusually large individual. A whole skeleton of

Edmontosaurus may be seen on Level 1 (Accession # 867) in the Currelly Gallery. About 42 feet (13 m) long, 10 feet (3 m) tall at the hips, and may have weighed up to 3.5 tons.

Edmontosaurus is amongst the largest varieties of the hadrosaurs. Had no crest on the skull. Had a toothless beak and hundreds of cheek teeth, arranged in rows or batteries, that it used to

grind up its food. Walked on four legs. Could not achieve a full gallop, rather more of a brisk walk. Could likely

stand and move on hindlegs for a brief time. No natural defenses. Was a herding animal. Perhaps ate pine needles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves.

Revised: January 15, 2008 Page 2 of 2

3. Information


Among the contemporaries of Edmontosaurus in Canada were Albertosaurus, Nanotyrannus,Parasaurolophus, Corythosaurus, Lambeosaurus, Euoplocephalus, Kritosaurus, andPachyrhinosaurus.

Named by Lawrence M. Lambe in 1917 from a fossil found in Edmonton Rock Formation, inAlberta, Canada.

Fossils have been found, in Alberta, Canada, and Alaska, Wyoming, Montana and New Jersey inthe USA. Two mummified Edmontosaurus fossils were found in Wyoming, USA.

Had skin with a pebbly texture.





Hadrosaurs

Gryposaurus

Data Sheet


Full Name: Gryposaurus incurvimanusCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Hadrosaurines (flat skull with no crest)Found Where: Red Deer River, Alberta, CanadaFound When: 1918Age: Late Cretaceous Period, 70 million years oldReal?: Yes

Accession #: 764 – more or less full skeleton

2. Description

Name means “griffin lizard”, also called “hook-nosed lizard”. Large, plant-eating, duckbill dinosaur (family Hadrosauridae). About 30 feet (9 m) long, and may have weighed up to 2-3 tons. Had no crest on the skull. Had a toothless beak and hundreds of cheek teeth, arranged in rows or batteries, that it used to


stand and move on hindlegs for a brief time. Look along the backbone to see the ossified (bony) tendons that helped keep the backbone stiff

and horizontal, and also fragments of skin preserved as impressions. Had skin with a pebblytexture.

No natural defenses. Was a herding animal. Perhaps ate pine needles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves.


3. Information


Among the contemporaries of Gryposaurus in Canada were Albertosaurus, Nanotyrannus,Parasaurolophus, Corythosaurus, Lambeosaurus, Euoplocephalus, Kritosaurus, andPachyrhinosaurus.

Named by Lawrence M. Lambe in 1914. Fossils have been found, in Alberta, Canada, Montana, USA, as well as possible Gryposaurs

found in South America. It is similar to Kritosaurus, and for many years was regarded as thesame genus.

This is the first dinosaur ever acquired by the ROM. Recently, the quarry site of the originalexcavation has been found in Dinosaur Provincial Park in Alberta.

Revised: March 15, 2007 Page 1 of 1




Hadrosaurs

Skin

Data Sheet


Full Name: Not identifiedCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Lambeosaurines (hollow fan-shaped or tubular skull crest)

orHadrosaurines (flat skull with no crest)

Found Where: Alberta, CanadaFound When: Early 1900’sAge: Late Cretaceous Period, 70 million years oldReal?: Yes

Accession #: 855 – skin impression

2. Description

Invite visitors to touch this specimen!! Skin impression from a large, plant-eating, duckbill dinosaur (family Hadrosauridae). Dinosaurs had dry scaly skin. The pattern varied over the body, as in living reptiles. This fossil

preserves an impression of the skin from the back or flank of a duck-bill’s body. Impossible to identify from which type of hadrosaur the skin came. Hadrosaurs had a toothless beak and hundreds of cheek teeth, arranged in rows or batteries, that

it used to grind up its food. No natural defenses. Was a herding animal.

3. Information

Hadrosaurs lived during the late Cretaceous period, roughly 90 to 65 million years ago, towardthe end of the Mesozoic, the Age of Dinosaurs. A huge, mass extinction killed the dinosaurs 65million years ago.





Hadrosaurs

Partial Jaw with Tooth Battery

Data Sheet


Full Name: Not identifiedCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Lambeosaurines (hollow fan-shaped or tubular skull crest)

orHadrosaurines (flat skull with no crest)

Found Where: Alberta, CanadaFound When: Early 1900’sAge: Late Cretaceous Period, 70 million years oldReal?: Yes

Accession #: 3499 – partial jaw with tooth battery

2. Description

Partial jaw from a large, plant-eating, duckbill dinosaur (family Hadrosauridae). Impossible to identify from which type of hadrosaur the jaw came. Hadrosaurs had a toothless beak and hundreds of cheek teeth, arranged in rows or batteries, that

it used to grind up its food. In place of teeth at the front of hadrosaur jaws, there was a flat, duck-like bill for cropping

vegetation. Behind the bill, the jaws contained a battery of teeth arranged in rows to shred plantmaterial. Exceptional hadrosaur specimens have preserved stomach contents, which includefruits as well as rough plants and twigs. Hadrosaurs clearly had a varied diet. Perhaps ate pineneedles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves.


3. Information

Hadrosaurs lived during the late Cretaceous period, roughly 90 to 65 million years ago, towardthe end of the Mesozoic, the Age of Dinosaurs. A huge, mass extinction killed the dinosaurs 65million years ago.





Hadrosaurs

Hadrosaur Trackway

Data Sheet


What is it?: Cast of a trackway – tracks left by some dinosaurCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurFound Where: Shores of the Peace River, near Hudson’s Hope, British

Columbia, CanadaFound When: 1965Age: Early Cretaceous Period, 130 million years oldReal?: Fibreglass cast made from a latex rubber mould

Accession #: 12867

2. Description

Palaeodetectives – ROM palaeontologists made a latex mould of this trackway where it wasfound on the shores of the Peace River in 1965. Soon after, a massive hydroelectric project wascompleted, flooding the valley with a deep reservoir.

Except rarely, when a trackway is found with the remains of an animal that died while making it,cannot be sure which dinosaur was responsible. However, it is likely that these footprints weremade by a hadrosaur that was walking slowly on all four feet. There is no tail print – therefore thetail was kept off the ground.





Hadrosaurs

Lambeosaurus

Data Sheet


Full Name: Lambeosaurus lambeiCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Lambeosaurines (hollow fan-shaped or tubular skull crest)Found Where: Red Deer River, Alberta, CanadaFound When: Early 1900’sAge: Late Cretaceous Period, 70 million years oldReal?: Mostly real fossils on display

Accession #’s: 1218 – more or less full skeleton, found 1919758 and 869 (found 1934) – juvenile skulls794 – skull

2. Description

Large (largest-known), plant-eating, duckbill dinosaur (family Hadrosauridae). About 30-50 feet (9-15 m) long, 7 feet (2.1 m) tall at the hips, and may have weighed between 5-6

tons. Had a hollow, bony, hatchet-shaped crest on top of its high, domed head. For the Lambeosaurines, the nostrils went up through the crest. There are several theories – the


Had a toothless beak and as many as 1,600 cheek teeth, arranged in rows or batteries, that itused to grind up its food.




Perhaps ate pine needles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves.

3. Information


Among the contemporaries of Lambeosaurus in North America were Albertosaurus,Nanotyrannus, Parasaurolophus, Corythosaurus, Euoplocephalus, Kritosaurus, Tyrannosaurusrex, Triceratops, and Pachyrhinosaurus.

The first duckbilled dinosaur to be found in North America, at the Oldman Formation, Alberta. Lambeosaurus was named by ROM palaeontologist, Dr. William A. Parks, in 1923 to honour

Lawrence Lambe, an early Canadian fossil hunter. Fossils have been found in North America, including Montana, USA, Baja, Mexico, and Alberta,

Canada. Had skin with a pebbly texture. Fossilized skin and footprints have been found.





Hadrosaurs

Maiasaura

Data Sheet


Full Name: Maiasaura peeblesorumCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Hadrosaurines (flat skull with no crest)Found Where: Montana, USAFound When: Early 1990’sAge: Late Cretaceous Period, 70 million years oldReal?: Cast (real fossils are in the research laboratories)

Accession #’s: 44770 – more or less full skeleton (cast)Acquired with the support of Padulo Integrated Inc.

44684 – hatchling skeleton (cast)

2. Description

Name means "Good Mother Lizard”. The Maiasaur is very important as it is the first species thatconclusively proved to scientists that some dinosaurs were social creatures that cared for theiryoung. The legs of the baby Maiasaura are too undeveloped for it to have run around, but wearon its teeth shows it was not newly hatched. This suggests that adults carried food to the nest,possibly for several months. Parents were bringing food, likely regurgitated leaves, berries, andnuts.

Maiasaurs built their nests by scooping a 6 foot (1.8 m) wide basin out of the dry ground. Thenests, containing up tp 25 eggs, each the size of a grapefruit, were spaced 23 feet (7 m) apart(one Maiasuar body length), so that the parents could come and go without disturbing themaiasaurs tending to other nests. One ‘nursery’ in Montana supported 40 nests covering a 2.5acre (1 hectare) area.

Large, plant-eating, duckbill dinosaur (family Hadrosauridae). Most complete, best specimen of Maiasaura found to-date. About 30 feet (9 m) long, 6-8 feet (2-2.8 m) tall at the hips, and may have weighed between 2-3

tons. Had no crest on top of the skull, but there was a small crest in front of the eyes.




No natural defenses. Was a herding animal. Scientists believe that maiasaurs lived and moved across North America

in large herds. Evidence for this comes from discoveries of skeletons grouped together in massgraves. One site in Montana contains the bones of over 10,000 maiasaurs that seem to havebeen overcome and buried by volcanic ash.

Perhaps ate pine needles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves. When hatched, newborn maiasaurs weighed about 1.5 pounds (680 grams) and were about 14

inches (0.36 meters) long. By the end of their first year, they were already 8 feet (2.4 m) long,well on the way to the adult size.

3. Information


Maiasaura lived alongside Parasaurolophus, Corythosaurus, Orodromeus, Velociraptor, Troodon,the ceratopsid Centrosaurus, the tank-like Euoplocephalus, Ankylosaurus, Tyrannosaurus rex,Daspletosaurus torosus and Albertosaurus. It was among the last of the dinosaur species toevolve.

Thousands of fossils have been found in North America, in western Canada and the westernUSA.

Had skin with a pebbly texture. Maiasaura is the official state fossil of Montana, USA. Maiasaura is the only dinosaur with a female name. First Maiasaura specimen described and named by palaeontologists Jack Horner (advisor for the

Jurassic Park movies) and Robert Makela in 1979. Found at the Two Medicine formation inwestern Montana.

A Maiasaura bone fragment and a piece of eggshell from Maiasaura flew with astronaut LorenActon on an 8-day mission (Spacelab 2) in 1985. This was the first dinosaur in space.

Current mount is a NEW cast – the 1990’s cast has been retired. The old cast was not correct,as the hands were not right.





Hadrosaurs

Parasaurolophus

Data Sheet


Full Name: Parasaurolophus walkeriCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Lambeosaurines (hollow fan-shaped or tubular skull crest)Found Where: Red Deer River, Alberta, CanadaFound When: 1920Age: Late Cretaceous Period, 70 million years oldReal?: Mostly real fossils on display; head is a cast


2. Description

Name means "Near Saurolophus (Crested Lizard)" which refers to another hadrosaurid,Saurolophus, discovered before Parasaurolophus.

Large, plant-eating, duckbill dinosaur (family Hadrosauridae). Best known of the hadrosaurs; considered to be rare (only 6 specimens have been found). About 40 feet (12 m) long, 8 feet (2.8 m) tall at the hips, and may have weighed between 2-3

tons. Had an extremely long, backwards-leaning, hollow, tubular-shaped, bony skull crest; had the

largest crest of any of the hadrosaurs - up to 6 feet (1.8 m) long. For the Lambeosaurines, the nostrils went up through the crest. There are several theories – the


Had a notch in its back, right where the crest would touch the back when its head leanedbackwards.




No natural defenses. Was a herding animal. Perhaps ate pine needles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves.

3. Information

Head is a cast – this is the most complete head known, and is the global reference standard –studied by palaeontologists from around the world; housed in the research laboratories. This isthe MOST famous specimen in the collection.


Among the contemporaries of Parasaurolophus in North America were Albertosaurus,Nanotyrannus, Lambeosaursus, Corythosaurus, Euoplocephalus, Kritosaurus, Tyrannosaurusrex, Triceratops, and Pachyrhinosaurus.

The first duckbilled dinosaur to be found in North America, at the Oldman Formation, Alberta. Parasaurolophus was described and named by ROM palaeontologist, Dr. William A. Parks, in

1922 from this almost complete skeleton. Fossils have been found in North America, including New Mexico and Utah, USA, and Alberta,

Canada. Had skin with a pebbly texture. Parasaurolophus appeared in all three Jurassic Park films. During the Brachiosaurus scene in

the first film, when the camera trails to a full view of the park, a herd is seen near the lake.Parasaurolophus appeared again in The Lost World: Jurassic Park when InGen tries to capturedinosaurs for the San Diego Jurassic Park. This dinosaur appears again in Jurassic Park III. Thepeople on the island run into a herd of Parasaurolophus and Corythosaurus while trying toescape Velociraptor.




Currelly Gallery

Hadrosaurs

Prosaurolophus

Data Sheet


Full Name: Prosaurolophus maximusCommonly called a: Hadrosaur or duckbill dinosaurBelongs to broad classification: Ornithischian (bird-hipped) dinosaurPart of group called: Hadrosaurines (flat skull with no crest)Found Where: Red Deer River, Alberta, CanadaFound When: 1921Age: Late Cretaceous Period, 70 million years oldReal?: Yes


2. Description

Name means “before Saurolophus”, in comparison to the later dinosaur with a similar head. Large, plant-eating, duckbill dinosaur (family Hadrosauridae). About 30 feet (9 m) long, and may have weighed up to 2-3 tons. Had no large crest on the skull. Had a toothless beak and hundreds of cheek teeth, arranged in rows or batteries, that it used to


stand and move on hindlegs for a brief time. Look along the backbone to see the ossified (bony) tendons that helped keep the backbone stiff

and horizontal. Tendons are soft tissue, and rarely fossilized. Had skin with a pebbly texture. No natural defenses. Was a herding animal. Perhaps ate pine needles, conifers, ginkgos, seeds, cycads, twigs, and magnolia leaves.


3. Information


Among the contemporaries of Prosaurolophus in Canada were Gryposaurus, Albertosaurus,Nanotyrannus, Parasaurolophus, Corythosaurus, Lambeosaurus, Euoplocephalus, Kritosaurus,and Pachyrhinosaurus.

Named by Barnum Brown in 1916. Fossils have been found, in Alberta, Canada, Montana, USA.





Stegosaurus

Data Sheet


Full Name: Stegosaurus sp.Belongs to broad classification: Ornithischian (bird-hipped) dinosaurFound Where: Dinosaur National Monument and Cleveland-Lloyd Quarry, both in Utah,


bones of many individuals

Accession #: 7982

2. Description

Name means “roof-lizard”. A herbivore (plant-eater). Skull’s low position suggests that it browsed low-growing vegetation. Idea is

supported by the fact that there were no front teeth, but a horny beak. Head is very small in relation to body. Brain also correspondingly small but large enough to perform

function for which it was needed. Also a nerve centre at base of spine. Recently, it has been argued thatthis space (also found in sauropods) may have been the location of a glycogen body, a structure in livingbirds whose function is not definitely known but which is postulated to facilitate the supply of glycogen tothe animal's nervous system.

Teeth cannot be seen. A small number of weak teeth which replaced themselves constantly. Teeth weresmall and triangular in shape.

The plates on the back are the most prominent characteristic – but there has been much speculation as tofunction. For defence? Has been called a "walking fortress". For temperature control? Note canalsindicating network of blood vessels on plates. Suggested that they served function of warming up body ordissipating heat so that Stegosaurus could maintain constant body temperature – much debated idea!!Most palaeontologists now agree that they formed a pair of alternating rows, one running down each sideof the midline of the animal's back.

The tail is a "striking" means of defense. The tail was thick and strong with 2 pairs of sharp spikes. Likely moved slowly. Averaged about 30 feet (9 m) long, 14 feet (4 m) in height, and may have weighed up to 5.5 tons.

3. Information

Among the contemporaries of Stegosaurus in North America were Allosaurus, Camptosaurus, Apatosaurus(formerly known as Brontosaurus), Diplodocus, Camarasaurus, Ceratosaurus, Brachiosaurus,Lesothosaurus, and Compsognathus.


Described and named in 1877 by Othniel Charles Marsh. Fossils have been found in North America, including Colorado, Utah and Montana, USA, and Portugal in

2006. Stegosaurus is the official state dinosaur of Colorado. Almost as popular as T. rex in popular culture – very popular at museums; has appeared in many films.

Appeared in Jurassic Park. Had skin with a pebbly texture.





Tyrannosaurus rex

Data Sheet


Full Name: Tyrannoosaurus rexBelongs to broad classification: Theropod dinosaur; SaurischianFound Where: Montana, USAAge: Late Cretaceous Period, 70 million years oldReal?: Cast

Accession #’s: 46200 – full skeleton55379 – juvenile skull and jaws1335 – adult skull and jaws

Acquired by: Full skeleton – acquired with the support of Bram and Bluma Appel,Martha and Richard Hogarth, Members of the Royal Ontario Museum, theDepartment of Museum Volunteers, the Madeleine A. Fritz VertebratePalaeontology Fund, and the ROM Reproductions Association.

Juvenile skull and jaws – Gift of the Louise Hawley Stone Charitable Trust.

2. Description

Name means “Tyrant Lizard King”. Among the largest known of the meat-eaters. Its eyes faced forward, giving it stereoscopic vision. Had good vision and a keen sense of smell. Ear structure similar to that in crocodiles, which have well-

developed sense of hearing. Presence of efficient ear implies possibility of some vocal ability, presumablyused to recognize others of its species. Brain casts indicate a long olfactory tract (smell?).

To support its massive head, its body and neck are short and deep compared with other carnivorousdinosaurs.

A carnivore (meat-eater). Had a large head with scissor-action jaws, and sharp, serrated teeth that musthave been capable of ripping through the muscles and bones of the largest prey. The structure of its jawallowed all the teeth to engage at once when biting. Teeth that may be worn out were continually replaced.Had 50 to 60 thick, conical, bone-crunching teeth that ranged in size from very small to over 9 inches (23cm) long. Adults had a variety of sizes of teeth in their jaws at one time, as teeth were broken and new(smaller) ones grew in to replace them. One T. rex was found with some teeth up to 13 inch (33 cm) long.T. rex could eat up to 500 pounds (230 kg) of meat and bones in one bite! Tyrannosaurus rex had a wrap-around overbite; when T. rex closed its mouth, the upper parts of the lower jaw's teeth fit inside the upperteeth. Powerful neck muscles aided in ripping away of large chunks of meat. Narrow front teeth may havebeen used to reach awkward gaps to tug out pieces of flesh. Bite shown to be three times as powerful asthe bite of a lion.


Re: juvenile skull - the shape of an animal’s skull often changes markedly from the juvenile to the adultstage. This skull was originally thought to be from a new species of small theropod. Paleontologists nowrealize it represents a juvenile Tyrannosaurus. Look throughout the galleries for other examples that showhow dinosaurs and other animals changed as they grew.

The clawed hands and feet were effective for grappling and ripping prey. The front claws may havegrasped prey while the hind ones kicked and slashed – the arms were tiny, and could not have been usedin locomotion, but were powerful. Although not able to reach mouth, probably quite strong (could lift about450 pounds). Had powerful hind legs with three-taloned feet, and short arms equipped with small, two-fingered hands. Forearm and hand bones not found until 1989 and 1990 in Montana.

Like a lion – one kill, such as a large hadrosaur, would likely last for 2-3 weeks. Although juveniles were agile, adults were likely too big and heavy to have managed more than a brisk

walk or slow run. Likely capable of short burst of speed as high as 40 kilometers per hour (25 mph) –probably as fast or faster than animals they preyed upon.

Since T-rex was the largest predator of its time, was able to scare away other feeding animals and mayhave fed largely on already dead animals even though an effective hunter - much as presently happens inthe animal world.

Tyrannosaurus bataar, an Asian species formerly called Tarbosaurus bataar is smaller than T-rex. Close relative of the Albertosaurus, but much larger. About 40 feet (12.4 m) long, about 15-20 feet (4.6-6 m) tall, and may have weighed up to 5-7 tons. The

arms were about 3 feet (1 m) long. The skull was about 5 feet (1.5 m) long. The jaws were about 4 feet (1.2 m) long.

3. Information

Lived during the late Cretaceous period, roughly 83 to 65 million years ago, toward the end of theMesozoic, the Age of Dinosaurs. A huge, mass extinction killed the dinosaurs 65 million years ago.

Among the contemporaries of Tyrannosaurus rex in North America were Lambeosaurus, Nanotyrannus,Parasaurolophus, Corythosaurus, Euoplocephalus, Kritosaurus, Albertosaurus, Triceratops, andPachyrhinosaurus.

First found by Edward Drinker Cope in 1892, but misnamed as Manospondylus gigas. Named in 1905 byHenry Fairfield Osborn.

Fossils have been found in western North America, and Mongolia. Had skin with a pebbly texture. Has become the most widely-recognized dinosaur in popular culture. It is the only dinosaur which is

routinely referred to by its full scientific name (Tyrannosaurus rex) among the general public, and thescientific abbreviation T. rex has also come into wide usage (commonly misspelled "T-Rex"). Museumexhibits featuring T. rex are very popular; an estimated 10,000 visitors flocked to Chicago's Field Museumon the opening day of its "Sue" exhibit in 2003. T. rex has appeared numerous times on television and infilms, notably The Lost World, King Kong , The Land Before Time, Jurassic Park, and Night at the Museum.A number of books and comic strips, including Calvin and Hobbes, have also featured Tyrannosaurus,which is typically portrayed as the biggest and most terrifying carnivore of all. At least one musical group,the band T. Rex, is named after the species. Tyrannosaurus-related toys, including numerous videogames and other merchandise, remain popular. Various businesses have capitalized on the popularity ofTyrannosaurus rex by using it in advertisements.




Some Dinosaur Theories and ObservationsThe purpose of this document is to discuss some recent theories about dinosaurs which are accepted aseither possibilities or probabilities by paleontologists.

Much comes from the script of the traveling show, "Dinosaurs, Past and present" which was at the ROMat the end of 1988, and the catalogues are in the Volunteer Library. An article in "Newsweek", October 28,1991 has also recently been approved by the Vertebrate Paleontology Department since it is based onquotes from leading dinosaurologists, all of whom are linked at present with US establishments. A littlediscussion of some of these new discoveries and theories adds interest to the tour of the galleries, andone finds that quite a number of visitors have heard of some of the theories largely because there are somany articles in the popular press nowadays. Examples given are related to the specimens on view at theROM whenever possible.

CAVEAT: Dr. McGowan asked that we be careful to stress that these are all theories and not facts.

1. Reconstruction of Dinosaurs

Since dinosaurs ("terrible reptiles") were named by Richard Owen (a British Professor ofAnatomy) in 1841, dinosaur bones have been put together or reconstructed in many differentways as the pool of knowledge increased.

It is rare to find a complete skeleton of any dinosaur species so conjecture is often based on veryincomplete evidence. Over the years the world-wide pool of knowledge has greatly increased,and there are many joint exploration ventures between experts in different countries.

Changes in reconstruction have taken place over the years, as new knowledge is gained. Forexample, Stegosaurus. The first Stegosaurus remains were found in 1877 - the firstreconstruction in 1891 showed the back plates in one single row standing up along the spine. By1899, the plates were shown as overlapping scales covering the animal's back like an armour,while a later reconstruction in 1901 showed the plates paired off in two parallel rows right down to8 (instead of 4) tail spikes. The current accepted reconstruction is two offsetting rows, as in…


Muscle scars - In "Dinosaurs, Past and Present" work was shown indicating that the muscle scarswhich are present on fossilised bones could aid in reconstruction of skeletons.

Skin - fossilized casts of dinosaur skin - have been found, as well as skin impressions, and fromthese it is conjectured that some dinosaurs had skin similar to present day reptiles, such aslizards. There is, however, no evidence about colour, and there probably will never be any.

Sex - the sex of dinosaurs cannot be determined from fossilized remains. There is a possibilitythat minor differences between some closely similar species could in actual fact be sexualvariations of the same species.

2. Dinosaurs and Birds

It is well accepted that present day birds developed from one branch of therapods. This was firstproposed by Thomas Henry Huxley in the 1860s and 70s. At that time there were few dinosaurfinds. During the 1870s and 80s, there were many new dinosaur discoveries and the relationshipsbetween dinosaur skeletons and birds became much less clear and did not have strong support.

The first (of 6 found to date) Archaeopteryx was found in 1861. In 1973, John Ostrom revived theidea of a therapod ancestry for birds. He noticed that bones from Deinonychus, a carnivorousdinosaur similar to Velociraptor but found in Montana rather than Mongolia, were very like those ofArchaeopteryx.

3. Warm-Blooded, Cold-Blooded?

Traditionally all dinosaurs were considered slow-moving, cold-blooded reptiles. In 1965, LorisRussell suggested that dinosaurs might have been warm-blooded and in 1968, Robert Bakkercontended that they were fast moving and warm-blooded, and he remains the chief proponent ofthis view at present.

The argument for the warm-blooded theory can be stated as follows: mammals are superior toreptiles today, the reason being they are warm-blooded, or endothermic ("internal heat"). Sincemammals and dinosaurs evolved at practically the same time the endothermic mammals shouldhave prevailed. For the dinosaurs to have radiated at the expense of the mammals, dinosaursmust have been as "competitive" as mammals, and therefore must have been endothermic or‘warm-blooded’.

Body temperature of dinosaurs, like skin colour, cannot be established, so a definitive resolutionof the warm-blooded theory cannot be found.

4. Herds of Dinosaurs?

Much early dinosaur material assumed that they were solitary creatures; this was due to the smallnumber of finds available in the early days.

Now that there is a vast pool of knowledge throughout the world which is being shared, the view isthat in areas where dinosaurs flourished, there was probably a situation similar to the savannahplains of Africa. In these areas, herds of various mammals co-exist, the majority beingherbivorous, while there are a smaller number of carnivorous predators, maintaining a balancebetween species and the environment.

As is the case with mammals in the African plains, there were many other types of living things co-existing with the dinosaurs. A picture is being built up of a complex society of living things,dominated by the various dinosaur families.


Fossilized trackways have been discovered which indicate that dinosaurs often travelled in herds,and there is a possibility that some migrated seasonally, as do caribou nowadays.

5. Dinosaur Nurseries

The first fossilized dinosaur eggs were found in the Gobi Desert in 1922. They were the eggs ofProtoceratops. These eggs were about 8 inches in length, were elongate and were sometimesfound in nests. As many as 25 eggs have been found in one place and it is conjectured byMichael Brett-Surman of the Smithsonian Institute that several mothers laid their eggs in one nest,presumably as a communal protection device.

Since the first finds of eggs, fossil nests, embryos, eggs and young have been found in otherareas such as Montana, Argentina and Alberta, and they give an idea that some of the dinosaurspecies lived a communal life. Jack Horner has been involved with excavations near Chocteau,Montana, of two specific areas, known as Egg Mountain and Egg Island, and much that is knowncomes from his work. As well as finding fossilized evidence of Hypsilophodont nurseries whichindicates that the animals returned to the nests year after year, the chief findings are to do with theMaiasaur ("good mother lizard" - a crestless hadrosaur). Horner's work on the Maiasauraindicates that some hadrosaurs looked after their young in a nesting colony and that after layingeggs the nest would be covered with sand by the mother and the territory perhaps defended.Possibly the parents brought food when the nestlings hatched.

6. Extinction

When discussing the dinosaur extinction it should always be remembered that this event wasmerely one of many extinctions during the history of planet Earth. This extinction appears to us tobe more extreme than many others due to the physical size of the best known dinosaurs.

Dinosaurs existed from roughly 230 million years ago, during the Triassic Period to 65 millionyears ago (a time span of 165 million years, give or take). During that time dinosaur speciescame and went, and it is estimated that at the final extinction, 65 million years ago, fewer than 12of a total of 300 known dinosaur genera were around to become extinct - the others had alreadycome and gone! It seems clear that this extinction was caused by a drastic change in theenvironment. However, it is not known whether this was due to a sudden catastrophic event orsomething that happened gradually over a million years or so, or a combination of the two.

Regardless, there were changes in geography. Ocean levels fell and vast shallow inland seasdried up. Mountains rose from the plains, and floodplains and swamps vanished. The dinosaur=sideal environment disappeared.

There were changes in climate. Global temperatures fell, and seasons of changing weatherappeared. This brought on changes in vegetation, and a loss of food supply. Dinosaurs wereunable to migrate to warmer areas. Old routes were cut off by continental breaks. Dinosaurswere not able to adjust to a colder climate, unlike mammals with fur, or birds with feathers. Thesefactors could have brought a great decline in numbers beyond the point of recovery.

Current thinking postulates a global catastrophe, such as an asteroid or meteorite striking theEarth about 65 million years ago. This would have produced a huge dust cloud shutting out thesunlight over a long period of time. This is like a nuclear winter effect. Clues are found in thelayer of iridium found in rocks at the K-T Boundary. Evidence of a very large crater has beenfound off the Yucatan Peninsula, Mexico.

Mammal-type animals existed before dinosaurs and became mostly extinct during the Triassicperiod. The fossilized remains of the small mammals which are found from the same time as the


dinosaurs did not become extinct at the time of the demise of the dinosaurs and they paved theway for the variety of mammal life that we have today.

It should be noted that not all reptiles became extinct at the same time as the dinosaurs. Twosuccessful survivors are turtles and crocodiles. See the Tuatara in the Reptile Gallery.

Dinosaurs left descendants in the modern birds, now thought to have evolved from theropods.

7. Mass Extinctions

Various literature refers to several mass extinctions over time. The one 65 million years ago thatwiped out the dinosaurs is but one.

In biology, extinction is the dying out or termination of a race or species. Extinction occurs when aspecies can no longer reproduce at replacement levels. Most extinctions are thought to haveresulted from environmental changes that affected the species in either of two ways:

The doomed species might not have been able to adapt to the changed environment, andthus perished without descendants.

OR

The species may have adapted, but in the process, may have evolved into a distinctlynew species.

Extinction is an on-going feature of the Earth’s flora and fauna - the vast majority of species everto have lived are already extinct. However, the fossil record shows a number of mass extinctions,each involving the demise of vast numbers of species. One such took place at the end of theCretaceous Period (65 million years ago), when the dinosaurs and much of the marine life of theday perished. Evidence points to the HYPOTHESIZED impact of an asteroid hitting the Earth asthe cause. It is suspected that catastrophic events - such as an asteroid impact - may havetriggered other mass extinctions as well. In fact, mass extinctions appear to have taken placeabout every 26 million years, which has led some paleontologists to propose that a cyclical cosmicevent causes these periodic die-offs.

One recent mass extinction took place about 11,000 years ago. In particular, in North America,many types of large mammals perished - mammoths, mastodons, ground sloths, giant beavers,and others. Two main theories have been proposed as a cause:

The Overkill Hypothesis - overkilling by human hunters, supported by the timing of themass extinctions, and by the appearance of large numbers of human hunters, asevidenced by the Clovis complex, an ancient culture centred in North America. Clovisarchaeological sites (mainly in Arizona, New Mexico, and west Texas) have yieldeddistinctive projectile points, and date to between 10,000-12,000 years ago.

The Climactic Change Theory - abrupt changes in climate and vegetation during the lastglacial and inter-glacial times. Again, these changes took place in the appropriate timeframe to account for the mass extinctions.

During the Permian Period (275 - 225 million years ago), a major (but perhaps not mass)extinction involved many types of plants, and the demise of trilobites - which had flourished from540 - 245 million years ago - a long run!! No good theories as to why!!

The first known mass extinction ended the Precambrian Period (4,570 - 570 million years ago),


and very few fossils of either plants or animals from that time have been found.

The mass extinction at the end of the Cretaceous Period is best known, and many theories areavailable. On land, dinosaurs and flying reptiles like pterosaurs perished, but plant life was hardlyaffected. About 83% of marine plankton genera (plural of genus) perished. Marine ammonitesand belemnites went, as did marine reptiles like ichthyosaurs, mosasaurs, and plesiosaurs. Manytypes of corals and bivalves vanished.

Since the early 1980s, most attention has been on the so-called asteroid theory formulated byAmerican scientist Walter Alvarez, and his father, Luis Alvarez. Briefly, this theory states that theimpact of an asteroid (or meteorite) on the Earth might have triggered the mass extinction byejecting a huge quantity of rock debris into the atmosphere. This shrouded the Earth in darknessfor several months or longer. With no sunlight able to penetrate this global dust cloud,photosynthesis ceased, green plants died, and seeds went dormant, disrupting the entire foodchain.

Some paleontologists are sceptical - many propose theories about environmental factors as acause. In particular, at the end of the Cretaceous Period, tectonic plate movements in the Earth’scrust caused a major rearrangement of the world’s landmasses. The climactic changes resultingfrom such continental drift could have caused a gradual deterioration of the habitats that werefavourable to dinosaurs or other animal and plant groups. Of course, it is possible that a suddencatastrophic event like an asteroid impact could have been concurrent, contributing further to theenvironmental deterioration.

Other proposed causes have included disease, heat waves and resulting sterility, freezing coldspells, the rise of egg-eating mammals, to X-rays from a nearby exploding star supernova.

ROM Curators favour the asteroid theory - but research continues!!

8. The K-T Boundary and the Asteroid Theory

Notes on extinctions refer to the K-T Boundary. This refers to the above described massextinction that took place at the end of the Cretaceous Period, or at the beginning of the TertiaryPeriod - the Cretaceous-Tertiary Boundary - or the K-T Boundary. ‘K’ is the symbol used bygeologists to mean Cretaceous.

Ongoing debates about this particular mass extinction pits the catastrophists against thegradualists. Were the extinctions simultaneous and instantaneous, or were they nonsynchronousand spread over a long time period. Geologic time measurement is not precise. Attempts topinpoint the K-T Boundary event give a result with a statistical margin of error of about +/- 500,000years. The actual time involved in the mass extinction remains undetermined.

However, the discovery of an abnormally high concentration of the rare metal iridium at, or veryclose to, the K-T Boundary, provides what has been recognized as one of those rareinstantaneous geologic time markers that seem to be worldwide. This iridium anomaly, or spike,was found first by Walter Alvarez (mentioned above) in the Cretaceous-Tertiary boundarysequence at Gubbio, Italy, in the 1970s. Since then, the spike has been found in many locations,both in rock outcrops on land, and in core samples drilled from ocean floors. Normally, iridium israre in rocks of the Earth’s crust (about 0.3 parts per billion). At Gubbio, the concentration is morethan 20 times the normal, and it’s even higher elsewhere.

Levels of iridium are higher in meteorites than on the Earth. The iridium anomaly is thought to beextraterrestrial in origin. The level of iridium in meteorites has been accepted as representing theaverage level throughout the solar system, and by extension, the universe. Thus, the high iridium


concentration at the K-T Boundary is thought to be the result of the collision between the Earthand a huge asteroid or meteor - the asteroid theory of mass extinction. Whatever it was, theobject is estimated at about 10 km or 6.5 miles in diameter, and 1 quadrillion metric tons inweight. At the time of impact, its speed would have been several hundreds of thousands of milesper hour. The crater at the impact site (called an astrobleme) would be 100 km or more indiameter. No such crater has been recognized or acknowledged as yet. However, given that theEarth’s surface is 2/3 ocean, the impact site would likely be hidden on the ocean floor. Sometheories suggest that Hudson’s Bay or the Caribbean Sea may be the impact sites. The resultingdust cloud would have deposited the higher iridium concentration around the globe, and impactedsunlight, photosynthesis, and so forth, as described above.

9. Taphonomy

The location where fossils are found may not be the place of death since so many things canhappen after death. The body can be moved by predators (think what crocodiles do to their prey)or by water. Consequently just because a herd of dinosaurs is found in petrified river silt does notnecessarily make them aquatic creatures, they could have been washed away by flooding -and soon.

Taphonomy is the name given by the Russians to a specific type of paleontology. It comes fromthe Greek for "burial" and "laws". Taphonomy is the attempt to reconstruct the facts of thecorpses' burial so that how and where it lived is revealed.



Gallery interpreters

Fossilization Versus PetrificationThe difference between something fossilized and something petrified can be confusing. See below.

From The Illustrated Encyclopedia of Dinosaurs, Dr. David Norman, page 17....

Fossilization: The word fossil used to mean literally anything that was dug out of the ground.Nowadays its meaning has become more restricted to the preserved traces or remains of ancientorganisms.

The essential requirement for fossilization is that the organism (be it plant or animal) or evidenceof its activities (such as footprints, droppings, gnawings, pollen grains, etc.) should be covered insediment of some kind before scavenging animals or the natural processes of erosion or decaycompletely destroy them ....

It is usual for only the hard parts, shells, teeth and bones to be preserved as fossils since theseare the things that are most resistant to decay....

Hard parts such as bone and teeth can be preserved in a number of ways. Teeth are particularlyresistant and are frequently preserved in their original state. Most other hard parts are changed toa greater or lesser extent. Bones have a considerable amount of organic material in them; whenburied the organic material (mostly collagen) decays or is dissolved away. Relatively recent fossilbones are often found in this state and are very light and crumbly. In older fossils the spacesaround the bone crystals are filled with new mineral from water seeping through the rocks. Thesecan be minerals such as silica, calcite or iron pyrites. This process of mineral replacement isknown as permineralization and makes the bones heavier.

On occasions the original mineral structure of the bone can be replaced by the minerals in thepercolating ground waters. The bone is then said to have been petrified or turned to stone.Permineralized and petrified bones retain their original structure as can be seen if examinedmicroscopically....

From Fossils and the History of Life, George Gaylord Simpson....

The changes that go on during the long presence of organic remains in their tombs in the rocksmay be more preservative than destructive. Most of these changes used to be called petrifaction,which means "converting into rock", and sometimes they still are so called, especially inapplication to fossil wood. The changes are quite varied, however, and often, cannotappropriately be described as the conversion of organic remains to rock. Paleontologists usuallyspeak of these processes simply as fossilization.



Gallery interpreters

How Are Fossils Formed?From An Introduction To Ontario Fossils, Janet Waddington....

Studying natural processes today makes us wonder that anything is preserved at all, for when a plant oran animal dies it is usually completely recycled. Soft tissue such as leaves or flesh either is eaten or itdecays through bacterial action until there is no trace of it left. Hard parts such as shell, bone, or woodare more resistant to decay, but they too are usually broken down gradually - through the action of wind,water, and tiny organisms - and become part of the soil.

Only if the plant or animal is shielded from these agents soon after death is there a slight chance that partof it may be preserved. Quick burial is one method of shielding it from destruction. Burial is most likely tooccur in areas where sediments accumulate rapidly - on ocean or lake bottoms or in swamps. It is leastlikely to occur in areas where no sediment accumulates or there is active erosion - on dry land or in fast-flowing water. Thus the chance that an animal or a plant will become a fossil depends as much on whereit lives as on what it is made of.

Many changes occur in the remains of an animal or a plant as it becomes fossilized. After burial the fleshyparts generally decay and disappear. (For this reason animals without hard skeletons are rarely found asfossils.) Shell, wood, and bone may be preserved unchanged, but more commonly they are altered bychemicals in the ground water seeping through them. The pores in bone or wood may become filled withminerals such as silica and literally turn to stone (petrification). The original material of the hard partsmay be changed to a completely different material while retaining the same shape and structure(replacement). Sometimes a shell dissolves to leave a cavity or mould of the original in the sediment.Later this mould may be filled in to form a cast or replica of the shell. Sometimes, especially with plants,the remains are broken down chemically to form a thin carbon film (carbonization).

Other types of fossils are not formed directly from the remains of animals. Among these are impressionsleft in soft mud, and trace fossils - tracks, trails, and burrows made by animals as they went about theirdaily business. Very rarely the entire remains of ancient organisms may be found unchanged. Forexample, complete mammoth carcasses have been found preserved in the Arctic permafrost of Siberiaand Alaska.

Once a fossil is formed it may still be changed, or even destroyed, by processes within the earth's surfacewhich alter the rocks in which the fossil is buried. Fossils start out as animal or plant remains buried inlayers of sediment - sand, mud, or gravel. In time these layers of sediment themselves are buried,harden, and become sedimentary rocks. The rocks may be uplifted and eroded, or excavated to exposethe older underlying layers. Until this happens the fossils in the rocks are usually inaccessible to man.

Since fossils are the record of past life, is there any way of knowing how long ago they lived? Fossils arepreserved in sediments laid down in layers or strata, one on top of another. Thus the lowest layers musthave been deposited first and be older than any layers overlying them. However, the appearances of therocks vary from place to place, making it difficult to recognize rock strata of the same age in differentplaces.


In the late 1790s a surveyor named William Smith made a detailed study of the rocks and fossils he foundwhile working on a canal project in England. He noticed that each different layer in the rocks contained adistinctive group of fossils. Furthermore, he discovered that from place to place across England the fossilgroups always appeared in the same order. Thus the distinctive combinations of fossils could be used toidentify the rock strata. This knowledge formed the basis for a calendar of earth history - a geological timescale - see the separate document titled Time Eras in the Fossil Record.

The time scale inspired by Smith's work tells us the order in which things occurred - without any dates.Reading the fossils is a bit like looking through an old album with no labels on the photographs. Dressstyles, car models, the presence or absence of certain objects in a familiar landscape are all clues whichcombine to give an accurate sequence of events even if dates are missing. While mini skirts may comeback into fashion from time to time, mini skirts and the Beatles at the same time happened only once. Inthe same way, one particular type of fossil may appear in rocks of different ages, but it is found incombination with certain others only at one specific level.

Geological time has been divided up into periods, similar to periods of modern history, for example,Victorian, Georgian, and Elizabethan. These units of time are not all of the same length, but are periods inwhich certain events occurred or certain monarchs reigned. The evidence for events in modern periodsmay be seen in furniture and buildings; the evidence for geological periods is found in the fossils. Thegeological periods are grouped into eras, representing major blocks of earth history, just as recordedhuman history is broken down into, for instance, BC and AD. A glance at the names of these eras revealsthe influence that fossils have had in the development of the time scale. Paleozoic, Mesozoic, andCenozoic mean "ancient", "medieval",and "modern" life respectively.

The geological time scale deals with relative time. It may tell us that a certain rock layer is older oryounger than another, but it does not give the age of either layer in years. Absolute time, the age ofrocks in years, can be determined by analysis of radioactive materials in the rocks. These materials breakdown spontaneously at a constant rate, different for each element, to form different substances. Forexample, uranium changes to lead, and potassium produces argon. Since scientists know the rate ofchange and can measure the relative amounts of uranium and lead or potassium and argon in rocks, theyare able to calculate the time interval since the rocks formed, that is, the age of the rocks. In this way anabsolute time frame has been added to the relative time scale for earth history.

The names in the geological time scale refer only to the periods of time during which the sediments thatform the rocks were laid down. During any one period, a great variety of rocks formed. These have beenfurther subdivided by geologists into formations - units defined by actual physical features such as thecolour, the texture, and the chemical composition of the rock. Thus period refers to the age of the rocks,while formation refers to the specific rock layers in a particular region.




Dinosaurs

Composite versus Cast Reproduction Bones

In some instances, a complete dinosaur skeleton was not found, and specimens on display are made upas a so-called composite. Real bones are used, but bones taken from the skeletons of many differentindividuals. Good examples are the Allosaurus, Stegosaurus, and Camptosaurus.

These real bones in turn may be used to make plaster casting. A good example is the Maiasaura. Acomplete casting was done – the one displayed to the public is the cast, while the original is safeguardedin the Museum’s research laboratories.



Earth's Timeline4.6 billion years = 1 calendar year

Era Time of Year What was Happening?

Archaezoic January 1

end of February Rocks above the surface of the water.

March 29 LIFE - one-celled bacteria; microbial mounds - stromatolites

August 22 Rocks show rust; oxygen build up; atmosphere forming.

Proterozoic October 22 SEX - exchange of genetic material ~ 900 million years ago. Firstresult was algae.

~ November 9 Simple animals made up of many cells.

November 16, 17 Cambrian explosion - greatest burst of diversity ever known on Earth.Burgess Shale activity (~10 million years = 24 hours)

Paleozoic November 27 First fish - first vertebrates.

end of November Plants move onto land.

December 1 Winged insects.

December 3 Coelocanth

December 4 First amphibians.

December 11, 12 Major EXTINCTION - : of plants and animals wiped out.

Mesozoic December 13, 14 First mammals.

December 15 First dinosaurs.

December 19 First birds. ROM Jurassic Gallery.

December 26 morning ROM Cretaceous Gallery.

December 26 Major EXTINCTION - 2 of plants and animals wiped out.

Cenozoic December 28 Ostrich.

December 31 ~ 6:30 pm First humans.

December 31 ~ 1 minute to midnight Hunter/gatherers become farmers as population grows from ~150million to 6 billion.

December 31 < 1 minute to midnight First civilization (Mesopotamia).

December 31-3 seconds to midnight Columbus reaches America.

Today Today Major extinction in progress - wiping out many species

Adapted from materials prepared by Renee Bozowsky

Revised: April 1, 2001


Time Eras in the Fossil Record

Era

Du

rati

on

(mill

ions Period

Du

rati

on

(mill

ions

Sta

rte

d(m

illio

nsof Evolution of Life

As Recorded by Fossils

Cenozoic 65

Quarternary 3 3 Origin & Evolution of humans

Tertiary 62 65 Evolution of mammalsAt start, extinction of dinosaurs

Mesozoic 160

Cretaceous 70 135Zenith of dinosaursBony fishesFlowering plants

Jurassic 55 190 First birdsDevelopment of giant dinosaurs

Triassic 35 225First dinosaursFirst mammalsAt start, wide extinctions

Paleozoic 345

Permian 50 275 Dominance of mammal-like reptiles

(Pennsylvanian)Carboniferous(Mississippian)

70 345First reptiles

Dominance of amphibians

Devonian 55 400First amphibiansAir-breathing fishesPrimitive land plants

Silurian 30 430 First jawed fishesFirst land-living animals

Ordovician 70 500 Jawless fishes

Cambrian 70 570First vertebratesInvertebrates widely establishedAppearance of numerous fossils

‘Precambrian’ 4,000Fossils are rareAlgaeOrigin of Earth

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