Dinosaur Extinction Flashcards
What does extant mean?
Still living today
What does extinct mean?
species where all members have died
What is a mass extinction event?
Dramatic environmental changes that trigger the extinction of many species all at the same time
What are the five major mass extinctions?
End Ordovician, Late Devonian, End Permian, End Triassic, and The End-Cretaceous
What happened during the End-Cretaceous Mass Extinction?
All non-avian dinosaurs died, mosasaurs and plesiosaurs died, pterosaurs also died, and there were also corals, plankton, ammonites, and land plants that didn’t make it
What traits made it more likely for a species the survive the end-cretaceous mass extinction?
small and semiaquatic
Which crocodilian survived the end-cretaceous but went extinct afterwards?
Champsosaurs
What are the leading factors today that cause extinctions of animals?
Human activity, Habitat Loss and Pollution
What layer in the earth is considered to be the cretaceous palogene boundary and what interesting minerals did it contain?
A clay layer first discovered in Italy, contained Iridium (rare on earth), tektites, and shocked quartz
What are tektites?
tiny pieces of rock that have been melted and then cooled
What is Shocked Quartz?
A form of the mineral quartz with a unique internal structure that can only be created through exposure to a powerful shockwave
What structures in the chicxulub peninsula suggested that there was a meteor impact?
Cenotes arranged in a crescent shape
How big was the chicxulub meteor?
10 km wide
What were the other hypotheses for the end-cretaceous mass extinction?
Small mammals ate all dinosaurs eggs, widespread glaciation and freezing temperatures, mass volcanic outgassing
What did the meteorite impact cause that would kill so many species?
Huge tsunamis, large cloud of super-heated rock and dust, wildfires, global increase in temperature (heat blast), reduced sunlight from debris in atmosphere (no photosynthesis)
