Triassic - Mesozoic Flashcards
What are all the eons, eras, and periods that we have learned?
What is considered to be the transition to the modern era?
MESOZOIC ERA
Triassic, Jurassic, and Cretaceous periods
How was the state of the whole world at the start of the Triassic?
(Hint: End of Permian)
The whole world was HOT due to the SIBERIAN FLOOD BASALTS
Earth was supercharged with CO2 emissions globally
How hot did the land surfaces in Pangea get during the start of the Triassic?
Lands of Pangea got up to 40 degree Celsius
Year round got hotter than the highest recordings in Death Valley
What is the correlation between ocean temperature and the oxygen concentration within it?
As the temperature of the ocean RISES, oxygen concentration goes DOWN
What evidence supports the presence of anoxic waters during the P-T mass extinction?
Evidence from bioturbation
Rocks deposited during and following the extinction event lack signs of bioturbation
Bedded with little disruption
What is associated with bioturbation?
RESURGENCE OF SEAFLOOR MICROBIAL MATS AND WRINKLE STRUCTURES
Life had to essentially start over after the extinction, back to simpler life forms
Extinction was so bad, had to go back to pre-Cambrian lifestyles
What took over the sandy beaches for a brief moment, following the P-T mass extinction?
Wrinkle structures
What is the P-T boundary?
Transition from fossiliferous limestones to stromatolites
Animals disappear and microbes take over
What is important to note about the change between the Permian and Triassic?
It is very DISTINCT and UNMISTAKABLE
Changes from massive reefs in the Permian to scattered shells in the Triassic
How many fossils remain in great abundance in the record during the Triassic?
ONLY 5 fossils remain in great abundance
One inarticulate brachiopod and four bivalves
the four bivalves : Claraia, Eumorphotis, Unionites, Promyalina
How long would it take for diveristy to rebound during triassic?
About 100 million years, LARGEST MASS EXTINCTION late permian
MODERN FAUNA
Bivalves, Gastropods, Sea Urchins, Crustaceans, Sponges, Sharks, Bony Fish, Marine Reptiles, Mammals
REEF GAP
The P T mass extinction was followed by a significant reef gap with NO REEFS
Reefs that would eventually return would be different
NEW REEF BUILDER
Scleractinia
Paleozoic reefs
They contained tabulate corals and rugose corals, WENT EXTINCT AT THE P T
New corals were scleractinia
Series of ridges within coral
Called septa
where polyps rest upon them
Symmetry within coral
ALLL Scleractinia coral septas have a RADIAL symmetry and are divided into 6 major septa
RUGOSE CORAL septa have a BILATERAL symmetry