Dinosaur Extinction Flashcards
species that are still present today are called
a) extinct
b) extant
c) alive
b
list the species alive during the following period/eon/era
end permian
marine invertebrates, insects, synapsids and anapsids
list the species alive during the following period/eon/era
end cretaceous
marine invertebrates and reptiles, birds, pterosaurs and dinosaurs, marine diapsids
list the species alive during the following period/eon/era
end ordovician
marine invertebrates
list the species alive during the following period/eon/era
end triassic
pseudosuchians and marine organisms
what animals made it through the end cretaceous extinction
mammals, turtles, amphibians and fish
what species survived the end cretaceous extinction only to go extinct during the Miocene
champsosaurs - crocodile-like aquatic diapsids
what is the name of the flightless aquatic bird mentioned in the lesson
a) Mosasaurus
b) Hesperonis
c) plesiosaurs
b
mosasaurus is a
a) giant marine lizard
b) aquatic bird
c) giant pterosaur
c
describe the Tasmanian tiger/wolf and what is its actual species name
thylacine
-> large carnivorous marsupial that went extinct in the zoo
what are the species that went extinct due to intense hunting and habitat loss
carolina parakeet, passenger pigeon and thylacine
many biologists argrued earth is in the middle of its sixth mass extinction … why
being brought on by sudden global climactic change and large ecosystem degradation -> humans
what did the italian stratigrahapher find out during the Paleogene and Cretaceous periods
he was studying rock layers -> discovered grey clay -> had high concentrations of iridium, a common component of meteorites
what was the grey clay, found by the italian stratigrapher, composed of
iridium - rare element
tektites - tiny pieces of rock that have been melted and cooled
shocked quartz - form of mineral quartz by powerful shockwaves
where was the peculiar pattern of cenotes found
mexico’s yucatan peninsula
what is another name for cenotes
limestone sinkholes
what was strange about the finding of cenotes
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)
how old was the massive ring of displaced limestone layer and and how was this found out
66 million years
radiometric dating
What is the prevailing theory that explains the cause of the End-Cretaceous extinction? Elaborate.
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
What kinds of animals survived the meteorite impact and how?
- turtles, champsosaurs, crocodilians, small mammals, birds
- small enough to easily find shelter (whereas dinos were too large)
- not at top of the food chain
Why is there a low likelihood that dinosaurs could be brought back from extinction?
DNA is very delicate (i.e. could not be preserved until now)
