Mammalogy:Introduction to Mammals

General

• ~ 5000 species in ~26 orders

• >500 new species since 1982; ~ 10 /year

• monophyletic group• derived from therapsids,

the mammal-like reptiles about 200 mya

 The olinguito, a species of raccoon-like carnivore discovered in the Andes in 2014. 

Laotian giant flying squirrel (Biswamoyopterus laoensis

Discovered in 2012 in a bush meat market in Laos

Unique Characteristics

• 3 ossicles

• hair

• mammae

Other Characters of Mammals:

• highly differentiated teeth; no more than two sets

• lower jaw of single bone

• four-chambered heart• anucleate mature red

blood cells• secondary palate

• well developed brain• endothermic• homeothermic• separate sexes, XX

and XY• internal fertilization• diaphragm• pulmonary artery w/3

semilunar valves

Even More….

• folded cerebellum• nerve filaments w/3

polypeptides• divided optic lobes• expanded and

differentiated facial musculature

• complex lung structure• epiglottis• single aortic trunk• 3 meninges in CNS

• erector pili muscles• sebaceous glands• sweat glands• loop of Henle in kidney• heart w/pacemaker and

Purkinje fibers• epiphyses in longbones

and girdles• Relatively very small

stapes

General

• Smallest: bumblebee bat or Savi's pygmy shrew; ~ 3 g.

• Largest: blue whale; to 160,000 kg

• Found on all continents

http://www.livescience.com/33049-smallest-mammals.html

Classification of Recent mammals

• Class Mammalia–Subclass Prototheria (early beasts)–Subclass Theria

• Infraclass Metatheria (changed beasts)-short gestation, highly altricial young

• Infraclass Eutheria (true beasts)-placental mammals

Classification of Recent Mammals

Subclass PrototheriaOrder Monotremata; 3 species

Subclass Theria Infraclass Metatheria (Marsupalia)

7 orders; 273 species; Includes:Order Didelphimorphia (opossums); 63 species

Infraclass Eutheria (Placentalia)18 orders; 4370 species: Includes:Order Xenartha (sloths, armadillos, anteaters); 29 speciesOrder Insectivora (moles and shrews); 429 speciesOrder Scandentia (tree shrews); 19 speciesOrder Dermoptera (tree shrews); 2 speciesOrder Chiroptera (bats); 928 speciesOrder Primates; 236 speciesOrder Carnivora; 271 speciesOrder Cetacea (whales); 78 speciesOrder Sirenia (manatees); 5 speciesOrder Proboscidea (elephants); 2 speciesOrder Perissodactyla (odd-toed ungulates); 18 speciesOrder Hyracoidea (hyraxes) 6 speciesOrder Tubulidentata (aardvark) 1 speciesOrder Arteriodactyla (even-toed ungulates); 220 speciesOrder Pholidota (pangolins); 7 speciesOrder Rodentia (rodents); 2024 speciesOrder Lagomorpha (rabbits, hares and pikas); 80 speciesOrder Macroscelidea (elephant shrews); 15 species

And now it’s YOUR turn!

• Order Monotremata and Order Didelphimorphia• Order Insectivora• Order Chiroptera• Order Primata• Order Carnivora• Order Cetacea• Order Perissodactyla• Order Arteriodactyla• Order Rodentia• Order Lagomorpha

The Pennsylvania Story

• 71 native species– 7 orders and 16 families

• 11 species extirpated– 3 of these reintroduced

• 4 species/subspecies are endangered in PA; 3 threatened– 2 of these are also listed federally

• 7+ are at risk or status undetermined• 4 exotics species; 2 other previous exotics

are now extirpated

Extirpated

Extirpated

Extirpated

Extirpated

Extirpated

Extirpated

Extirpated

Extirpated-Reintroduced

Extirpated-Reintroduced

Extirpated-Reintroduced

Extirpated-Reintroduced

PA EndangeredNorthern Flying Squirrel, Glaucomys sabrinus

PA/US EndangeredIndiana Bat, Myotis sodalis

PA/US EndangeredDelmarva Fox Squirrel, Sciurus niger cinereus

PA EndangeredLeast Shrew, Cryptotis parva

PA ThreatenedEastern Small-footed Bat, Myotis leibii

PA ThreatenedWest Virginia Water Shrew, Sorex palustris punctulatus

Allegheny WoodratNeotoma magister

ExoticNorway Rat, Rattus norvegicus

ExoticHouse Mouse, Mus musculus

ExoticHouse Mouse, Mus musculus

Exotic but Extirpated

European HareLepus europeaus

Black Rat, Rattus rattus

Nutria, Myocaster coypus

Feral Hog, Sus scrofia