Triassic -
After End Perm ME
2. Gradual Dinosaur Rise
Crocs dominated much of Triassic
Dinosaurs flourished after End-Triassic Mass Extinction
~ 50 ma after Siberian volcanism began
Dinosaurs prospered for ~100 Myr?
1. Rise of Archosaurs
Origin - soon after volcanism began
Rare & small footprints
Rare - boom/bust cycles
Archosaurs become more common
skeletons in fossil record
Archosaurs dominate Triassic
3. End Triassic Mass Extinction
Lasted ~600 kyr
Pangaea breakup - lotsa volcanism
less extensive than Siberian Traps
Crocodiles hit very hard
only a few survived
Dinosaurs survived & flourished
Recovered better than crocodiles
Not certain why they coped better
Achieved great diversity
Archosaurs Appear After End Perm
Appeared after volcanism ceased
Flourished - lotsa species & body types
Remaining archosaurs = birds, crocodiles
On both croc & bird lines of descemt
Crurotarsi = crocodile line
Aetosaurs
Phytosaurs
Avemetatarsalia = bird line
Pterosaurs
Basal dinosauromorphs