Lecture 15: Jurassic World 2

Question 1

Was there a slow recovery from the P/T extinction?

Answer 1

Things in the Triassic took a long time to reestablish…
The corals had almost completely been wiped out- reverted into sponges and stromatolites.
Corals didn’t reestablish themselves until late Triassic- scleractinians (‘hexacorals’).

Question 2

How did the corals in the late Triassic differ from the corals that preceded them in the paleozoic?

Answer 2

Symbiotic- they harbor other organisms in their tissues.
E.g photosynthetic dinoflagellates
Also an important member of the plankton

calcareous nannoplankton - coccolithophores appears also

Question 3

Some groups that were epifaunal…

Answer 3

start to develop individuals within the group that can burrow into the sediment.
The first group are the bivalves- soft tissue fuses into tube-like siphons (act like snorkels to keep them connected to water column above surface of sediment).

Question 4

What only just made into the Mesozoic?

Answer 4

The cephalopods.
Only one genus made it through the late Permian extinctions (P/T).
Only one family made it through T/J (end of Triassic).
…but gave rise to ammonites (one of the top marine predator groups)

Question 5

Triassic was the first geological period to see…

Answer 5

Frogs
Turtles
Marine reptiles flourish

Question 6

What dominates the Triassic on land?

What were the other ones?

Answer 6

Ferns but gymnosperms diversify
Cycads and their relatives dominate from Jurassic
Gymnosperm = ‘naked seed’

araucarians – Monkey Puzzle trees
ginkgos – Maidenhair trees

Question 7

Dinosaurs overview

Answer 7

reptiles
amniotic egg
internal fertilisation
all lived on land
all walked on upright straight legs
…and on tippy-toes

Question 8

When were dinosaurs existent?

Answer 8

all were Mesozoic (220 Ma - 66 Ma)

Question 9

What two main groups can dinosaurs be divided into?

Answer 9

the ‘lizard-hipped’ saurischians (incl. giant sauropods)

‘bird-hipped’ ornithischians

Question 10

Can begin to reconstruct true colour patterns

Answer 10

some fossil feathers preserve pigment cells (melanosomes)

Question 11

Making them live again…

Answer 11

trace fossils: trackways
identify type of dinosaur
determine speed, social behaviour, etc.

Question 12

Can tell what they ate?

Answer 12

gastroliths: stomach stones
coprolites: it’s all in the poo

Question 13

Can we now make them “talk”?

Answer 13

if birds are descended from dinosaurs…
in 2016 the first Late Cretaceous bird vocal organ (syrinx) was found
did dinosaurs also have the same vocal organs?