BZ214 Mammals (terms and taxonomy)

nourish offspring with milk

hair

alveolar lungs

endothermic

kidney with loop of Henle

Classic mammalia extant characteristics

medulla

cortex

cuticle

mammalian hair layers

undercoat

guard hairs

vibrissae

mammalian hair specialization

undercoat

thermoregulation

guard hairs

help to guard against environment, also part of markings and pelage color variation

vibrissae

sensory/tactile hairs

dentary

single jaw bone

quadrate to incus

articular to malleus

reptilian jaw bones that migrated to the inner ear

cuticle

outermost layer of hair,

protects inner layers and contributes to hair’s shine,

composed of overlapping flat cells

cortex

middle layer and largest component of the hair,

provides strength, color, and texture to the hair

contains tightly packed keratin fibers and melanin granules, which determine hair color

medulla

innermost layer, not always present in all hair types

contributes to the overall structure and may affect hair thickness

composed of loosely arranged cells, often filled with air

secondary palate

ventilation changes

heterodont dentition

jaw structure changes

skeletal mammalian characteristics

loss of lumbar ribs

diaphragm (and costal ventilation)

mammalian ventilation changes

costal ventilation

breathing that involves movement of ribs and intercostal muscles to expand and contract the thoracic cavity

heterodont

teeth with different shapes and in different places

heterodont

thecodont

diphyodont

mamalian dentition is usually

thecodont

teeth rooted in sockets

diphyodont

2 sets of teeth over lifespan

atlas and axis

cervical

thoracic

lumbar

sacral

caudal

sections of mammalian vertebrae

atlas and axis

where skull articulates with vertebrae, produces head shaking and nodding movement

cervical vertebrae

7 in nearly all mammals, make up the neck

thoracic vertebrae

12-15 vertebrae, articulate with the ribs

lumbar vertebrae

4-7 vertebrae, in lower back

sacral vertebrae

fused in most to form the Os-Sacrum

caudal vertebrae

make up the tail

Order Monotremata

2 groups: duck billed platypus and echidnas

oviparous, cloaca, reptilian gait

edentate (flat keratin plates in platypus

milk pad rather than teats

edentate

lack

Clade Metatheria

6 orders throughout americas and australia

angular process of lower jaw inflected

small braincase

short gestation (continue development in marsupium)

extended lactation period

epipubic bones present

Clade Eutheria

Placental mammals

Order Chiroptera, Order Carnivora, Order Perissodactyla, Superorder Cetartiodactyla (order Artiodactyla), Order Primates, Order Rodentia

Clade Eutheria Orders

Order Chiroptera

only volant mammals (only mammals capable of flight)

includes bats

Yangochiroptera and Yinpterochiroptera

Chiroptera suborders

Yangochirpotera

“micro bats”

large ears, small eyes

separated incisors

echolocation (in most)

claw only on 1st digit

Yinpterochiroptera

“megabats” (fruitbats)

small ears, large eyes

typically no echolocation

claw present on 1st and 2nd digits

Order Carnivora

includes carnivores, herbivores, and omnivores

carnassial pair (in most)

well-developed canines

simple GI tract

Carnassial pair

consists of 4th upper premolar and 1st lower molar

adapted for shearing meat

caniformia and feliformia

Carnivora suborders

Suborder Caniformia

“dog shaped”

includes canids, bears, pinnipeds, skunks, raccoons, weasels, and more

Suborder Feliformia

“cat-shaped”

includes felids, hyenas, mongooses, civets

Order Perissodactyla

Odd-toed ungulates

rhinos, horses tapirs

superorder cetartiodactyla

includes order artiodactyla

Order Artiodactyla

Even-toed ungulates

ruminants, camels/llamas, and pigs

includes clade cetacea

Clade Cetacea

Large fusiform bodies

mostly hairless, have blubber

forelimbs modified into flippers

telescoping of skull/rostrum

Order Primates

Increase in relative and absolute brain size

Forward facing eyes

divergent hallux (except humans)

increased mobility/dexterity of hands

Order Rodentia

Most specious group of extant mammals

2000+ species currently identified

worldwide distribution (except antarctica)

lack canines (diastema present in most)

have open rooted (“ever growing”) incisors