geologic time scale: dinosaur special edition Flashcards
when did dinosaurs appear?
during the TRIASSIC PERIOD
approximately 230 million years ago
when did dinosaurs ultimately disappeared?
at the end of the CRETACEOUS period,
approximately 65 million years ago
how long were dinosaurs on earth for?
for 165 million years
what era is known as the age of dinosaurs?
MESOZOIC ERA (which includes the TRIASSIC, JURASSIC and CRETACEOUS PERIODS)
did all dinosaurs meet?
Not all dinosaurs we have come to recognize lived (and died out) at them same time!
Ex: Stegosaurus (which lived during the Jurassic) was extinct 80 million years before Tyrannosaurus (which lived during the Cretaceous). The two never met!
what is the supercontinent known as? (when dinosaurs appeared approximately 230 million years ago (during the triassic period) the continents were stuck together)
pangea
why did the pangea gradually broke apart due to?
due to motion of Earth’s TECTONIC PLATE
by what time did dinosaurs go extinct and what happened to the continents?
65 million years ago and they started resembling what we see today
where was the largest Tyrannosaurus Rex discovered and when did it go extinct?
from Saskatchewan (a Canadian Province) and 65 millions years ago
when was the Tyrannosaurus rex discovered, known as scotty, and what did he weight?
in 1991 and approximately 9.8 tons
how many years did it take to remove Scotty’s fossil from the rock and it resulted in a skeleton of what percentage complete?
over 20 years and 65% complete
where can Scotty be seen?
at the Royal Saskatchewan
Museum
what did earth experience 65 million years ago?
the K-T (MASS) EXTINCTION EVENT
what does the k and t stand for in the k-t mass extinction?
K = Kreide (German for chalk and refers to
CRETACIOUS PERIOD)
Word CRETACIOUS comes from CRETA, which is Latin for CHALK.
T = TERTIARY (the period after CRETACIOUS)
K-T EXTINCTION EVENT ushers in the end of
CRETACIOUS, beginning of TERTIARY PERIOD.
what is the cretaceous period named after?
named after large quantities of CHALK (a form of LIMESTONE, made up of calcite, CaCO3) it left behind in Europe
what’s the percentage the K-T EXTINCTION wiped out and why did it do that much damage?
approximately 80% of animals thought to be caused by asteroid impact (or impacts)
what is the impact caused by the asteroid impact (or impacts)?
Such impacts ejected debris into the atmosphere, blocking sun and preventing photosynthesis.
This would be catastrophic to food chains.
May also have other factors such as changes in
climate, volcanoes, sea levels, etc…
did all dinosaurs died out because of the K-T EXTINCTION?
no, birds are dinosaurs and therefore theoretically reptiles.
also some AVIAN DINOSAURS (the ancestors of today’s birds) survived the K-T EXTINCTION EVENT whereas all NON-AVIAN DINOSAURS died out.
what do birds descended from?
from MANIRAPTORAN dinosaurs (from the MANIRAPTORA dinosaur group/clade).
give an example of a MANIRAPTORAN dinosaur that lived during the CRETACEOUS PERIOD.
BAMBIRAPTOR
what the group/clade of maniraptora palaeontologists believe birds were derived from approximately 150 million years ago during the JURASSIC PERIOD?
THEROPOD dinosaurs
what are theropod dinosaurs?
dinosaurs with hollow bones and 3
toes/claws on each limb.
what do maniraptorans feature like birds?
PROPATAGIUM
so what are birds compared to dinosaurs?
Thus, birds are dinosaurs (or at the very least, their descendants).
