Carnivora

Carnivora

Carnivory and Carnivora are not synonyms.

Most carnivora are specialized for ‘meat’ eating, but certainly not all.

Many other non-carnivora consume meat.2 suborders:

Caniformia = dog like: possess alisphenoid canal

Feliformia = cat like: usually lack alisphenoid canal

Grey wolf: alisphenoid

California sea lion alisphenoid

White tiger: no alisphenoid canal

Hemigalus derbyanus: civet – note bullae

Nandinia binotata: palm civet

Carnivora

It is easy to see how cats and canids fit this classification, but how about mustelids?

The 2 suborders are defined on the basis of the auditory bullae and the carotid circulation.

Furthermore, aquatic carnivores (Odobenidae, Otariida, and Phocidae) are pinnipeds (feather footed), while others are fissipeds (split footed). These were once suborders.

Carnivore Morphology

All carnivores have well developed canines.

They possess carnassial teeth formed by upper p4 and lower m1.

Carnassials are designed to shear through muscle and soft tissue, and in some, to slice through bone as well.

a: lionb: hyaenac: dogd: martene: mongoosef: bear

Carnivore Morphology

Skull shape reflects feeding strategy.

Compare the structure of the musculature of carnivores and herbivores, as well as the relative position of the mandibular condyle.

Compare the relative positions of the mandibular condyles and importance of primary chewing muscles: Temporalis in carnivores and masseters in herbivores.

Carnivore Morphology

Mandibular fossa differs too.

It has a ‘c’ shape in many, especially mustelids, that permits no lateral movement.

In procyonids and ursids, it is more likely to more ‘open’, allowing more lateral movement.

Why do you think that is?

Note the mandibular fossa in the mustelid and the bear.

What function might follow this form?

Carnivore Morphology

An important diagnostic characteristic of carnivores is the structure of the auditory bulla. Recall, this is derived from the angular bone of reptiles.

Recall, reptilian jaw articulation is quadrate-articular, while mammalian is dentary-squamosal.

Carnivore Morphology

Carnivores have 2 forms of auditory bullae formed by tympanic bone formed by tympanic and endotympanic.

In feliformes, the bullae are formed by the tympanic and endotympanic, and have a septum in between.

In caniformes, the bullae are formed by the tympanic, and there is no septum.

Carnivore Morphology

Most carnivores have a baculum. This is sort of interesting. What other

mammals have a baculum? Rodents. Why?

Carnivores also have induced ovulation!

Coincidence?

a: red foxb: racoonc: least weaseld: mongoosee: genetf: lion

Carnivore Morphology

Most have anal sace used for intraspecific communication (territoriality - home range etc.)

Sometimes, these are used for defense (skunks).

Absent in ursids, minimal in canids and felids.

Carnivore Morphology

Claws are prominent except in clawless otters (Aonyx), but even here they are vestigal.

Felids and viverids often have retractile claws.

No opposable digits.Centrale, scaphoid, and lunar are

fused.

Carnivore Morphology

Clavicle is reduced or absent. Permits increased stride length.

Two ways to run faster: 1) increase stride rate or 2) increase stride length.

Note: many ungulates also lack a clavicle.

Some are digitigrade (felids and canids) while others are plantigrade (ursids, procyonids). Difference in speed?

Carnivore Morphology

Size range is considerable: least weasel Mustela nivalis weighs 70g, while Ursus arctos weighs 800kg. What is the implication of this size range?

High protein diet has consequences for the digestive tract (incl. reduced ceacum).

Carnivory, omnivory, and herbivory.

Carnivore Evolution

First fossil carnivore dates to the late Cretaceous: Cimolestes.

Cimolestes is ancestral to both modern carnivores and the creodonts.

Creodonts lasted to the Miocene.

Cimolestes (Cretaceous): ancestral to creodonts?

Oxyaena (Creodont): carnassial is formed by m1-2 and m2-3.

Sinopa, Eocene creodont w/ M2-m3 carnassials.

Carnivore Evolution

2 lineages of early modern carnivores Viverravidae Miacidae

Both had P4/M1 carnassials.Both are from the early Eocene.Centrale, scaphoid, and lunar were

not fused.

Carnivore Evolution

Canids, felids, ursids, viverrids, and mustelids appear by the Oligocene.

Radiation of carnivores mirrors adaptive radiation of vegetation and potential prey items.

Earliest pinnipeds (enaliarctids) date to the late Oligocene.

Felimormia: Felidae

Worldwide dist’n except Australia, New Zealand, Madagascar, Japan, Oceanic Islands, and Poles.

36 species.All have shortened rostrum.

What are the consequences of this in terms of olfaction? Bite strength?

A) felid

B) canid

Note different proportions of large and small felid skulls. Is this an allometric effect?

Feliformia: Felidae

Felids kill via cervical dislocation, or suffocation.

Note extreme reduction in non-essential dentition.

Note reduction in molar battery, emphasis on slicing.

Feliformia: Felidae

Size ranges from 2kg to 300kg.Hyoid apparatus is cartilaginous -

resulting in ability to roar (purr in fifi).Claws retractile - except cheetah.Semi-arboreal.Papilla on tongue are angled

backwards.Hunting & Social strategies?

Feliformia: Hyaenidae

Old world, large carnivores to 80kg.4 genera and 4 species.Are both effective predators and

scavengers.Feldhammer asserts scavenging may

reduce competition between other carnivores and hyaenids. In Serengetti, most cats scavenge from hyaenids.

Feliformia: Hyaenidae

Can regurgitate undigestable items.Digitigrade w/ nonretractile claws.Fore-limb dominance is unusual. Why?Protrusable anal scent glands.Lack a baculum.Spotted Females have pseudopenis.

Why? Also, females > males. Laughing vocalizations.???

Compare skull and dentition of striped hyaena and aardwolf.

Spotted Hyaena utr

Feliformia: Hyaenidae

Crocuta crocuta - spotted hyaena is largest.

Hyaena hyaena - striped hyaena.Parahyaena brunnea - brown hyaenaProteles cristatus - Aardwolf

Feliformia: Herpestidae

Old world: 18 genera and 37 species of mongooses.

Recently separated from viverids..Size varies from 0.3kg to 5kg.Feeding generalists.Solitary - social. Terrestrial -

semiarboreal.Herpestes javanicus introduced to Hawaii.

Egyptian mongoose: Herpestes ichneumon.

Feliformia: Viverridae

20 genera and 34 species of Civets and genets.

Old world.Only mammalian carnivore on Madagascar.Wide variety of feeding styles: Frugivorous -

omnivorous - carnivorous.Peri-anal gland produces ‘civet. Civet uses

this for scent marking, we use it for perfume.

Note the similarity of the skulls: hence the previous unity of the families.

Genetta genetta: Small spotted genet.

Caniformia: Canidae

13 genera and 33 species of ‘dogs,’ in new and old worlds.

Dingo (Canis lupus dingo) was introduced to Australia and New Guinea about 4000 years ago.

Size varies from 1kg in Fenec to 80kg grey wolf.

Tend to be open, 2d hunters.

Caniformia: Canidae

Long limbs, nonretractile claws.Long rostrum = good olfaction.Oldest fossil dates to oligocene of

NA: Hesperocyon.Problems w/ taxonomy of ‘red wolf’.

Canis latrans

Caniformia: Mustelidae

25 genera and 65 species of badgers, weasels, skunks, wolverine, and otters.

Primarily northern hemisphere.Exclusively carnivorous. High energy

diet goes along w/ northern distribution and high sa/v ratio.

Long bodies, short limbs. 30g Mustela nivalis to 55kg Gulo gulo.

Caniformia: Mustelidae

Anal scent glands - think skunk.Monestrous, some have induced

ovulation, some have delayed implantation.

Taxidae taxus

Meles meles

Zorilla: African mustelid.

Note skull profiles.

Caniformia: Procyonidae

6 genera and 18 species restricted to new world.

1kg ringtail cat Bassariscus astutus to 18kg racoons.

Sexual dimorphism.Kinkajou Potos flavus has prehensile

tail. Kinkajou skulls and teeth follow.

Compare skull profiles between canids and procyonids.

Procyon: lack of allisphenoid canal

Procyon lotor

Procyon lotor

Procyon lotor: carnassials?

Nyctereutes procyanoides.

Caniformia: Ursidae

Historically: N. America, Andes of S. America, Eurasia, Atlas Mts. of N. Africa, in Arctic to tropical forests.

6 genera and 19 species (including greater and lesser pandas).

5kg lesser panda to 800kg grizzly.Sexual dimorphism is 20% in

monogamous forms, and 100% in polygamous forms.

Dentition geared to omnivory?

Caniformia: Ursidae

Only polar bears are strict carnivores.

Bears do not hibernate.

Grizzly bears once occurred in Mexico!

Caniformia: Pinnipedia

Pinnipeds are not entirely aquatic: they haul out for reproduction and to rest.

Morphologically similar because of constraints of aquatic and terrestrial life styles.

PhocidsOtariidsOdobenids

Caniformia: Pinnipedia

FusiformGenetalia are tucked away as in

cetaceans.Subcutaneous fat: energy storage,

insulation, and laminar flow.Propulsion by forelimbs in otariids

and odobenids - by hindlimbs in phocids.

Can you infer propulsive mechanism based on vertebral column?

Caniformia: Pinnipedia

Dentition usually tends to homodonty. Why?

There are exceptions: Crab eater seals Lobodon carcinophagus. (Crab eater seals actually eat krill which they filter from the water).

a, b) phocid: harbor seal. c, d) otariid: stellar sea lion and crab eater seal.

Lobodon carcinophagus

Caniformia: Pinnipedia

Curvature of eye enhances visionunder water, but poor vision on land. Have Tapetum lucida.

Good hearing under water to locate prey.

Diving adaptations: Bradycardia, blood shunting, increased hemoglobin + myoglobin.

Odobenidae

Monotypic. Includes only the walrus Odobenus rosmarus.

Dist’n is circumpolar in arctic.Mass to 1600kg. Sexual dimorphism. Blubber layer to 15cmLike otariids, ventral surface of flippers is

naked, and nails on 1st and 5th digits of hind flippers are rudimentary.

Odobenidae

Tusks in males and females: enlarged canines.

Tusks lack enamel.Tusks are used in aggressive

encounters, establishing dominance heirarchies, for feeding, locomotion, breaking through ice.

Otariidae

These are the eared seals. Includes fur seals and sea lions.

Marine only, in subpolar, temperate, or coastal waters.

7 genera and 14 species.Otariinae are the sea lions and have blunt

noses and little underfur.Arctocephalinae have pointed noses and

lots of underfur.

Otariidae

Feed on fish, crustaceans, and cephalopods.

Gregarious - may occur in groups containing up to a million individuals.

Breed on land. Males are polygynous and defend territories with 3 to 40 females.

Most exhibit delayed implantation.

Phocidae

True seals.10 genera and 19 species, in both polar and

subpolar water.2 subfamilies:

Phocinae of N. hemisphere have well-developed claws on all flippers.

Monachinae includes monk seals, elephant seals, and antarctic seals - reduced claws on hind flippers.

Phoca vitulina

Phocidae

Mass varies from 35kg to 3700kg.Generally lack underfur.Cheek teeth are multicusped.Not gregarious and do not form large

breeding colonies.Breed on the ice: note position of rear

flippers and limited terrestrial locomotor abilities.

Phocidae

Delayed implantation.Dive deeper and stay down longer

than otariids.