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C O U R S E 
Dinosaur Ecosystems
Michael Pittman, University of Hong Kong
C O U R S E   L E C T U R E 
Dinosaur Life and Extinction
Notes taken on February 10, 2017 by Edward Tanguay
features that are shared between groups of dinosaurs
anatomical features that are not found in other dinosaurs
Phanerozoic Eon (542 million years ago)
1. Paleozoic Era (524-251 Ma) ANCIENT
2. Mesozoic Era (250-65 Ma) MIDDLE
Triassic (250-200 Ma)
Jurassic (200-145 Ma)
Cretaceous (145-65 Ma)
3. Cenozoic Era (65 Ma - today) CURRENT
earliest dinosaurs
235 million years ago
middle Triassic
South America
middle Triassic
legs much more robust than their arms
appeared to have been carniverous
two meters long
much like the Velociraptor
lived much later: 75-71 Ma
but the first dinosaurs were probably covered in scales than feathers
South America is known for early dinosaurs
Late Triassic
228 Ma
231 Ma
225 Ma
231 Ma
228 Ma
South America
probably omnivores
dinosaurs have a acetabulum
characteristic hole in hip bone
250 million years ago, an extinction event occurred
wiped out almost 90 percent of all species of tetrapod
dinosaurs became dominant when non-dinosaurian reptiles became extinct
an extinct family of reptiles from the Triassic period that were distantly related to crocodilians
a group of mostly large Triassic archosaurs
Tyrannosaurus Rex
quintessential carnivore
one of the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event
found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 68 to 66 million years ago
focused on eating vegetation
North America
Jurassic period
the boundary between carnivory and herbivory is fluid in dinosaurs
the impressive range of diets found in living birds is a testament to the dietary diversity of their theropod ancestors
extinction of non-avian dinosaurs
impact event
10-kilometer wide asteroid or comet
dating of rock samples shows that non-avian dinosaurs went extinct at the same time as this event
formed the Chicxulub Crater in Mexico's Yucatan Peninsula
today partly buried
65.5-million-year-old clay layer deposited widely across the globe
high concentration of iridium
a chemical only found in meteorites or nuclear blast sites
generated tsunamis
triggered earthquakes with magnitudes of over 11 on the Richter Scale
debris that the explosion threw up, upon returning to earth encountered friction and started to heat up
raised Earth's surface temperature
firestorms likely caused a greenhouse effect
dust in the atmosphere hindered photosynthesis in the short term
led to collapse of ecosystems
the site of impact over sulphate-rich deposits released sulfuric acid aerosols that acidified the oceans
reduced sunlight getting to Earth's surface
effected ocean ecosystem and food chains
the non-avian dinosaurs were either killed instantaneously by the impact or died quickly in the extreme environment following it