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Flashcards in Skulls-Modifications Deck (20):
1

Describe 2° palate of birds & why

Soft, complete
-lighter -> lighter head -> better for flight

2

Define cranial kinesis

Articulation points in skull other than between upper & lower jaw

3

Who has a primary palate, and what is its function?

All vertebrates; separates brain from mouth (protects ventral brain)

4

What do mammals typically use their jaws and teeth for?

Mastication: chewing, grinding, slicing food

5

Describe 2° palate of mammals & why

complete - anterior: hard, posterior: soft
-Good to breathe while chewing (takes a long time)
-Adds strength
-Allows infants to breathe while creating suction for nursing

6

Who has an akinetic skull?

Mammals, turtles, crocodilians, most amphibians

7

What compromise do snakes have to make because of their kinetic skull?

Skull is weak, so can't eat living prey -> must paralyze with venom or kill by constriction first

8

Who has a 2° palate?

Mammals (complete, hard & soft)
Some turtles (partial, bony)
Crocodilians (complete, hard)
Aves (complete, soft)

9

Describe cranial akinesis in mammals

Bones are fused to withstand forces of mastication without jostling brain; aligns teeth (e.g. carnassials, molars) perfectly for slicing or grinding
-Lose kinesis, limiting food size

10

Who has a kinetic skull?

Many squamates, aves

11

functions of temporal fenestrae

-provide space for jaw muscles to expand during contraction
-more secure muscle attachment site
-less bone in skull is lighter

12

Function of 2° palate

Separate nasal passage from mouth (respiration vs. food)

13

Describe 2° palate of crocodilians & why

Complete: Allows breathing through nose while head is underwater
Bony: Withstand forces of wresting prey underwater
(Causes skull to be more akinetic)

14

Describe cranial kinesis in lizards

Provides more efficient prehension by having upper & lower jaw contact prey simultaneously, and redirecting forces into prey, not outwards/forwards

15

Which bones form the bony palate?

Maxilla, premaxilla, palatine (dermatocranium)

16

What do snakes do, since they have no 2° palate?

Stick out their trachea while they swallow their food

17

Who doesn't have a 2° palate?

Fish, amphibians, most lepidosaurs

18

How are temporal fenestrae a compromise?

Decrease brain protection (but also have chondrocranium beneath) to increase bite strength

19

What do amphibians and sauropsids use their jaws & teeth for?

Prehension: grabbing, holding food

20

Describe cranial kinesis in snakes

Many loose articulation points, connection of left & right lower jaw by flexible connective tissue (not fused) allows great flexibility