Week 8 Theropods 2

Question 1

What is the order of evolution of the following theropod clades: basal theropods, neotheropods, avetheropods, coelurosaurs, maniraptors, paraves and aves?

Answer 1

1. Basal theropods
2. Neotheropods
3. Avetheropods
4. Ceolurosaurs
5. Maniraptors
6. Paraves
7. Aves

Question 2

What is one character that separates these clades from other, more basal clades?

Answer 2

Neotheropods have a Furcula (wishbone)
Avetheropods Loss of 4th digit/finger
Ceolurosaurs developed feathers
Maniraptors have semi-lunate carpal bone in wrist
Paraves developed wings w/ layers feathers
Aves flight feather on wings

Question 3

Examples of basal dino for Basal Theropods clade

Answer 3

Herrerasaurus

Question 4

Example of basal dino from Neotheropods clade

Answer 4

Ceolophysis

Question 5

Example of basal dino from Avetheropods clade

Answer 5

Allosaurus

Question 6

Example of basal dino from Ceolursaurus clade

Answer 6

Deinocheirus

Question 7

Example of basal dino from Maniraptors clade

Answer 7

Oviraptors

Question 8

Example of basal dino from Paraves clade

Answer 8

Dromaesaurids

Question 9

Example of basal theropod from Avialae (Ave) clade

Answer 9

Archaeopteryx

Question 10

What does the anatomy of Spinosaurus tell us about its lifestyle?

Answer 10

It spent a lot of time in the water

Question 11

What fossil evidence exists of predator/prey relationships in the Mesozoic between theropods and ornithischians?

Answer 11

Fossilized tracks
Coprolites (poop)
Both showed evidence that both Theropods and Ornithischians lived very near eachother

Question 12

What are melanosomes and why are they useful for reconstructing what dinosaurs looked like?

Answer 12

Melanosomes are organelles that contain pigmentation which are usually involved in camouflage, mate attraction, and thermoregulation.
Can help reconstructing dinos for coloration reconstruction and fossilized feathers and skin evidence

Question 13

What characters of Achaeopteryx are bird-like and which are reptile-like?

Answer 13

Bird: feathers, fused broad wings, furcula, pneumatic bones
Reptile: small teeth, boney tail, 3 fingers/digits w/ claws

Question 14

How far back in the evolution of theropods do feathers go and what fossil evidence is there for that?

Answer 14

Feathers can be traced as far back as before Aves. Found in ceolurosaurs fossil and in tyrannosaurus fossil.