SOES2011 Dinosaurs

Question 1

What 2 structures allowed marine organisms to become terrestrial?

Answer 1

amniotic egg, water-proof skin

Question 2

What’s an amniota?

Answer 2

the reptile-synapsid clade

Question 3

Define seymouria

Answer 3

classic Permian seymouriamorphs

Question 4

What did amniotes first diverge into?

Answer 4

Synapsida (mammals and their relatives) and diapsida

Question 5

Describe disapsid?

Answer 5

diapsid = two holes in skull; eloginated limbs

Question 6

Describe the characteristics of reptiles

Answer 6

• skills covered by reptiles
• eggs are laid in ground, developing embryonary membranes and apergaminate (soft) or calcareous (hard) calcium carbonate shells. Some groups can develop embryo retention and viviparity.

Question 7

Define reptile

Answer 7

all members of the amniote clade that includes living turtles, lizards, crocs

Question 8

Define diapsid

Answer 8

reptiles with two skull openings behind orbit: the lizards

Question 9

Define neodiapsid

Answer 9

diapsid clade that includes Youniniformes + Sauria

Question 10

Define lepidosaur

Answer 10

tuatara and kin (rhynchocephalians) and squamates. Incredibly mobile skull

Question 11

Define squamate

Answer 11

snakes, lizards, amphinsbaenians (= ‘worm-lizard’. Include large fossilised marine organisms.

Question 12

Define archosauromorph

Answer 12

archosaurs and close relatives (like protosaurs & rynchosaurs)

Question 13

Define archosaur

Answer 13

crocodiles and kin, pterosaurs, dinosaurs and kin (including birds)

Question 14

Why doesn’t the term ‘reptile’ mean anything?

Answer 14

Not all the descendants of ‘reptiles’ are ‘reptiles’ - Reptilia are not monophyletic.

Question 15

Describe synapsida

Answer 15

Mammal-like reptiles, existed before the divergence of amniota into dinosaurs. BUT they are more closely related to humans than dinosaurs.

Question 16

Why were turtles and tortoises originally put basally?

Answer 16

The have an anapsid skull

Question 17

Name and describe the two holes in a diapsid skull

Answer 17

The supratemporal fenestra and the laterotemporal fenestra - allow muscle to go through skull and move jaw.

Question 18

Where do turtles go on the phylogenetic tree and why?

Answer 18

in the diapsida (from molecular evidence), despite having an anapsid condition (secondarily evolved)

Question 19

Describe Ichthyosaurs

Answer 19

dolphin-looking, jurassic period

Question 20

Give the six adaptations a reptile must make to transition back to water

Answer 20

• efficient movement through water
• effective feeding in water
• ability to regulate salt concentrations.
• buoyancy
• reproduction
• heat loss

Question 21

What is discontinuous locomotion

Answer 21

where propulsion is only generated during the power stroke, e.g. paddling, rowing

Question 22

Give the two categories of continuous locomotion

Answer 22

axial locomotion and paraxial locomotion

Question 23

Give the two types of axial continuous locomotion

Answer 23

axial undulatory swimming and axial oscillatory swimming

Question 24

Define axial locomotion

Answer 24

strokes powered by body and/or tail

Question 25

Define axial undulatory swimming

Answer 25

using wave-like sweeps of the tail

Question 26

define axial oscillatory swimming

Answer 26

using swivelling of a propulsive structure, like a tail fin.

Question 27

define paraxial locomotion

Answer 27

using lift or drag-based limbs

Question 28

Where are the salt glands in marine iguanas?

Answer 28

in the nasal cavity

Question 29

Where are croc salt glands?

Answer 29

tongue

Question 30

Where are sea snake salt glands?

Answer 30

under the tongue

Question 31

What are placodonts?

Answer 31

triassic sauropterygians, famous for crushing dentition.

Question 32

What are pachypleurosaurs?

Answer 32

small amphibious triassic sauropterygians. some suction-feeding features, viviparity

Question 33

Give a key feature of nothosauroids

Answer 33

interesting teeth

Question 34

Which organism is likely to have been first to use the ‘underwater flight’ movement?

Answer 34

pistosaurs (anscestors of plesiosaurs)

Question 35

What are Rhynchocephalians?

Answer 35

the living tuatara and their fossil relatives; enlarged back teeth, shearing/sawing motion to break up prey.