Dinosaur Extinction

Question 1

species that are still present today are called
a) extinct
b) extant
c) alive

Answer 1

b

Question 2

list the species alive during the following period/eon/era

end permian

Answer 2

marine invertebrates, insects, synapsids and anapsids

Question 3

list the species alive during the following period/eon/era

end cretaceous

Answer 3

marine invertebrates and reptiles, birds, pterosaurs and dinosaurs, marine diapsids

Question 4

list the species alive during the following period/eon/era

end ordovician

Answer 4

marine invertebrates

Question 5

list the species alive during the following period/eon/era

end triassic

Answer 5

pseudosuchians and marine organisms

Question 6

what animals made it through the end cretaceous extinction

Answer 6

mammals, turtles, amphibians and fish

Question 7

what species survived the end cretaceous extinction only to go extinct during the Miocene

Answer 7

champsosaurs - crocodile-like aquatic diapsids

Question 8

what is the name of the flightless aquatic bird mentioned in the lesson
a) Mosasaurus
b) Hesperonis
c) plesiosaurs

Answer 8

b

Question 9

mosasaurus is a
a) giant marine lizard
b) aquatic bird
c) giant pterosaur

Answer 9

c

Question 10

describe the Tasmanian tiger/wolf and what is its actual species name

Answer 10

thylacine
-> large carnivorous marsupial that went extinct in the zoo

Question 11

what are the species that went extinct due to intense hunting and habitat loss

Answer 11

carolina parakeet, passenger pigeon and thylacine

Question 12

many biologists argrued earth is in the middle of its sixth mass extinction … why

Answer 12

being brought on by sudden global climactic change and large ecosystem degradation -> humans

Question 13

what did the italian stratigrahapher find out during the Paleogene and Cretaceous periods

Answer 13

he was studying rock layers -> discovered grey clay -> had high concentrations of iridium, a common component of meteorites

Question 14

what was the grey clay, found by the italian stratigrapher, composed of

Answer 14

iridium - rare element
tektites - tiny pieces of rock that have been melted and cooled
shocked quartz - form of mineral quartz by powerful shockwaves

Question 15

where was the peculiar pattern of cenotes found

Answer 15

mexico’s yucatan peninsula

Question 16

what is another name for cenotes

Answer 16

limestone sinkholes

Question 17

what was strange about the finding of cenotes

Answer 17

the cenotes were arranged in a crescent shape, but the ends did not stop at the end of the peninsulas -> the limestone layer continued along the ocean floor (continuous ring)

Question 18

how old was the massive ring of displaced limestone layer and and how was this found out

Answer 18

66 million years
radiometric dating

Question 19

What is the prevailing theory that explains the cause of the End-Cretaceous extinction? Elaborate.

Answer 19

Chicxulub impact in the Yucatan peninsula
- initial impact caused tsunamis and wildfires
- cooked alive animals that were too large to seek shelter
- residual haze reduced sunlight –> reduce photosynthesis –> kill plants –> disrupt food chain

Question 20

What kinds of animals survived the meteorite impact and how?

Answer 20

• turtles, champsosaurs, crocodilians, small mammals, birds
• small enough to easily find shelter (whereas dinos were too large)
• not at top of the food chain

Question 21

Why is there a low likelihood that dinosaurs could be brought back from extinction?

Answer 21

DNA is very delicate (i.e. could not be preserved until now)