mammals origin and major groups

Question 1

what group did mammals evolve from

Answer 1

synapsid reptiles

Question 2

what are pelycosuars known for

Answer 2

sail-backed predatory synapsids

Question 3

what advanced synapsids led towards mammals

Answer 3

therapsids, inc cynodonts

Question 4

what evidence suggests cynodonts were warm blooded

Answer 4

fur, upright posture, heterodont teeth

Question 5

what is a key skeletal trait separating mammals from reptiles

Answer 5

three middle ear bones (malleus, incus, stapes)

Question 6

what type of teeth do mammals have

Answer 6

diphyodont (two sets), heterodont

Question 7

what is a tribosphenic molar

Answer 7

a 3 cusped tooth for cutting and crushing

Question 8

what is the purpose of the akinetic skull

Answer 8

precise occlusion, suckling, and efficient chewing

Question 9

what defines montremes

Answer 9

egg laying mammals with cloacas, no nipples

Question 10

name 2 living monotremes

Answer 10

platypus and echidna

Question 11

how does the platypus detect prey

Answer 11

electroreception in the bill

Question 12

what reproductive system do marsupials have

Answer 12

bifid penis, paired vaginas and simple placenta

Question 13

how are marsupials born so young

Answer 13

altricial (underdeveloped), crawl into pouch

Question 14

what is asynchronous lactation

Answer 14

marsupial mothers produce two milk types for young at different stages