Lesson 12: Dinosaur Extinction Flashcards
What are extant species?
species that are still present today
What are extinct species?
species whose members have all died off
What was the End Ordovician mass extinction?
affected only marine organisms, but at that time terrestrial organisms had only just begun to evolve
What was the Late Devonian mass extinction?
was largely limited to marine organisms, including some early vertebrate clades
What was the End Permian mass extinction?
saw the largest loss of diversity in all of Earth’s history
marine invertebrates were decimated, and this was the largest mass extinction of insects
on land, the synapsids were hard hit, as were the anapsids
What was the End Triassic mass extinction?
saw the extinction of most lineages of pseudosuchian archosaurs, as well as many of the synapsids that had survived the End Permian extinction, and also affected marine life
What was the End Cretaceous mass extinction?
occurred roughly 66 million years ago and killed all non-avian dinosaurs
in the oceans, large marine diapsids called mosasaurs and plesiosaurs, died out, as did many varieties of corals, several forms of plankton, and ammonites
land plants also lost many species in the extinction, and insect diversity fell
What types of animals survived the End Cretaceous mass extinction?
mammals, turtles, crocodiles, amphibians, and fish all made it through the extinction
What types of animals didn’t survive the End Cretaceous mass extinction?
it seems that large animals and photosynthetic organisms were the most likely to die off
small animals, and particularly those that were semiaquatic, had the best chance of surviving
What factors cause modern species to become extinct?
although deliberate hunting does not play as much of a role in the depletion of modern animal populations, habitat loss and pollution are significant contributors to the extinction of different species
What is iridium?
is a rare element on earth, but it is a common component of meteorites
What are tektites?
tiny pieces of rock that have been melted and then cooled
What is shocked quartz?
is a form of the mineral quartz with a unique internal structure that can only be created by exposure to a powerful shockwave, like those caused by a nuclear explosion or a meteorite impact
What are cenotes?
limestone stinkholes
What is the theory that mammals ate dinosaur eggs?
it has been suggested that dinosaurs went extinct because small mammals began eating all of the dinosaurs’ eggs
not only does this idea not take into consideration the fact that mammals and dinosaurs evolved at roughly the same time, but it also fails to explain why so many other kinds of organisms died out at the same time
