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Flashcards in mammals Deck (39):
1

monomermes

egg laying; e.g. platypus

2

marsupial

pouched e.g. kangaroos

3

placentals

e.g. gorilla

4

mammalia development from synamsid

post orbital opening merges with orbit

5

synapsids are

mammal like reptiles

6

characteristics of mammals

mammary glands
hair
endothermic
homeothermic
diapgram, 4 chambered heart, red blood cells without nuclei
live birth (minus monotrmes)
heterodton teeth
disphydonty
determinate growth
secondary palate
single jaw bone
3 middle ear bones
repsirotory turbinates
large brains
double articulations
upright posture

7

mammal characteristics derived from fossilr ecord

heterodton teeth
disphydonty
determinate growth
secondary palate
single jaw bone
3 middle ear bones
repsirotory turbinates
large brains
double articulations
upright posture

8

heterodont teeth

different types of feeth

9

dyphydonty

two sets of teeth

10

secondary palate

seperate breating and feeding passages

11

pelycosaurs

first synapsids
mammal ancestors
in fossil record 306 mya
had sprawling gait
quadrate articular jaw joint
nasal passages open into mouth

12

synasid evolution

pelycosaurs
therapsids
cynadonts
mammal like reptiles
mammals

13

what traits evolved into mammals

1. posture (sprawling to upright)

2. respiration (formation of secondary palate)

3. post dentary jaw bones to middle ear elements

14

therapsids

275/200 mya
more upright stance
quadrate articular jaw joint but dentary expanding up and back
some taxa with partial or complete secondary palata

15

cynodonts

255-170 mya
more upright posture
still quadrate articular jaw joint but post dentary jaw reduced
partial or complete secondary palate in all taxa
only two sets of complex teeht

16

earliest mammals

210 mya; mainly small and insectivorous and nocturnal
upright gait
complete secondary palate
at first; both quadrate articular and squamosal jaw joint

e.g. harocosium (mous like)

17

what did the articular and the quadrate evelop into

malleus and incus

18

cenzoic

age of mammals

19

meozoic

reptile age

20

palezoic

synapsid age

21

jurassic

mammalia evolution of shrews

22

creatacous

large animals start evoling

23

age of mammals

after k/pg extinction 65 mya;
mammals that made it through diverisifed quickly in terms of body size especially and specialization

24

what are mammal clades based on

reproductive strategies

25

placentals

long gestataion period, 5000+ species (95% of mammals)
diverse in numbers and types and biographic division

e.g. pangolins, armadillos, humans

26

monotremata

egg laying
earlist fossils from creatcous
teeth in beke
mammary glands without teets
no placenta

e.g. platapus echina duckbill

27

marsupials

pouched animals
early createacous
south america and australia mainly
anticlockwize radiation around world

e.g. koala kangaroos oppposums

28

4 major clades of placentals

1. laurosiatheria

2. eurochontoglieres

3. xenartha

5. afrotheria

29

laurosiatheria

shrews bats carnivores

30

eurochontoglieres

rabbits rodents primates

31

xenartha

anteaters sloths south america

32

afrotheria

elephants manatee africa

33

atriodactyl

morphology of limb; nails to toes to feets; prupose to elongate limbs to move faster

e.g. whales closely repalted to hippos (ceetartiodatylus)

34

angulates

tapirs, horses and rhinos, and whales
- walk on toes

35

whatl developments

pakicetus to choohacetus to basilosaurus to modern whale

36

pakicetus

50 mya wolf like mammals with enlogated skull and simplified teeth

37

roohacetus

46 mya more specialized for water
webbed feed and elongated digits

38

basilosaurs

37 mya
very whale like and elongated

39

hippos to whales

transitional fossils show that teeth and balen devloved from hippo to modern whale ancesotrs