Lecture 20

Question 1

Ostracoderm

Answer 1

Early jawless fishes

Question 2

Ostracoderm stratigraphic range

Answer 2

Ordovician-Devonian

Question 3

Chondrichthyans examples

Answer 3

Sharks and rays

Question 4

Actinopterygians examples

Answer 4

Ray-finned fishes

Question 5

Actinopterygian claim to fame

Answer 5

Represent over 50% of living vertebrate species

Question 6

First appearance of actinopterygians

Answer 6

Late Silurian

Question 7

Sarcopterygians

Answer 7

Lobe-finned fishes

Question 8

Sarcopterygians 2 main lineages

Answer 8

Coelacanths and rhipidistians

Question 9

Coelacanths

Answer 9

Remained in the oceans and are still around today

Question 10

Rhipidistians

Answer 10

Lived in estuaries and fresh water, and are the ancestors of all tetrapod (four-legged creatures)

Question 11

What are the earliest true tetrapods considered to be?

Answer 11

Stem group amhibians

Question 12

Amniotes

Answer 12

Evolved from amphibians
Vertebrates that have thicker and less permeable skin, breathe by expanding and contracting the rib cage, have 3 membranes around their embryos, etc.
Features allow them to live entirely on land

Question 13

Testudines

Answer 13

Turtles

Question 14

What are testudines?

Answer 14

A very early branch of the Pan-Reptilia

Question 15

Lepidosaurs

Answer 15

Lizards, snakes, etc.

Question 16

Lepidosaurs fossil record

Answer 16

Significant

Question 17

Archosaurs

Answer 17

Dinosaurs
Crocodilians
Pterosaurs
Birds

Question 18

Shared features of archosaurs

Answer 18

Teeth in sockets
Similar pattern of skull fenestrae
Pronounced ridge on femur
Ability to conserve water
Laid eggs

Question 19

4 basic dinosaur groups

Answer 19

Herresauria
Sauropodomorpha
Ornithischia
Theropoda