Skull

Question 1

What are the 3 types of skull morphology

Answer 1

Anapsid skull (No hole behind eye) (All dead)
Synapsid skull (One hole behind eye) (Mammals)
Diapsid skull (Two holes behind eye) (Reptiles)

Question 2

What are some feature of Nonamniotes

Answer 2

Undifferentiated adductor muscle - Buccal Bump = Snap closing and wider skull = Sucking animal in whole

Question 3

What are some features of early Amniotes

Answer 3

Differentiated adductor muscle - No buccal bump = Snap closing + Pressure once closed + narrow skull = Able to chew

Question 4

What was the general trend as evolution progressed through Thecodonts -> Crocodiles -> Dinosaurs -> Aves birds

Answer 4

A reduction in bone density/bone in general

Question 5

What are the general evolutionary trends in synapsid skull

Answer 5

Size of temporal fenestra - Condition of lower temporal bar - Lower jaw/joint - Teeth - Development of bony secondary plate - Presence of a patietal foramen

Question 6

What is the evolutionary synapsid trend with the size of temporal fenestra

Answer 6

Becomes increasing larger (Allows for greater jaw muscles)

Increasing tendency to enclose brain-case in dermal bone

Question 7

What is the evolutionary synapsid trend with the condition of the lower temporal bar

Answer 7

Presence of massaeter muscle (More efficient food processing)

Question 8

What is the evolutionary synapsid trend with the Lower jaw/joint

Answer 8

Tooth bearing part of the jaw dentary expanded

Question 9

What is the evolutionary synapsid trend with the Teeth

Answer 9

Greater specialisation of dentition (Homodont/Heterodont)

Question 10

What is the evolutionary synapsid trend with the Development of bony secondary plate

Answer 10

Allows breathing/feeding at the same time

Not in Pleycosaurs

Question 11

What is the evolutionary synapsid trend with the Presence of a patietal foramen

Answer 11

Hole in the skull for pineal eye

Not in mammals/Pleycosaurs