TOPIC 33: MAMMALS Flashcards
1
Q
shared derived traits of mammals
A
- mammary glands
- body hairé fur
- three middle ear bones
- endothermic
- dentary squamosal joint jaw
- specialized teeth
- big brain
2
Q
two things endothermy in animals is supported by
A
- four chambered heart
- metabolism
- vertical limb placement under body
- diaphragm
- intromittent organ
3
Q
lower jaw that carries teeth
A
dentary
4
Q
squamosal
A
small cranium bone
5
Q
middle ear bone
A
formed by relocation of the leftover jaw
6
Q
most mammals are
a) oviporous
b) ovovoporous
c) viviporous
A
c) viviporous
7
Q
mammals eveolved from ___
A
synapsids
8
Q
two things that show mammal evolution
A
- enlarged dentary bone
- seconday plate
9
Q
bone partition in between nasal and oral cavities
A
secondary plate
10
Q
extant clades of mammals
A
- monotremata
- marsupialia
- clade eutheria
11
Q
characteristics of monotremes (platypus and echidnas)
A
- lay eggs(oviporous) and provide milk
- no nipples
- cloacas
- lack teeth
12
Q
shared derived traits of clade marsupials and eutherians
A
- viviparous
- placenta
- post birth nourishment from nipples
13
Q
characteristics of marisoupals (opossums, kangaroos, and koalas)
A
- brief embryotic development
- partially born embryo
- no cloaca
14
Q
characterisitc sof eutherians (non-marsupial animals)
A
- complex placenta
- young feed on nipples after birth
- seperate urinary and anal openings
15
Q
where did primates evolve from
A
ancestors who inhabited trees of tropical regions
