[SunkenCiv]

Old-style topic, I had it saved into a file; refers to Devonian impact:

• New Crater Found Down Under

[anglian]

Your link is no mas.

[anglian]

New Crater Found Down Under April 2000
http://www.freerepublic.com/forum/a390081092974.htm
http://www.space.com/scienceastronomy/planetearth/sydney_crater_000421.html

[Lucius Cornelius Sulla]

Tracking back the therapsids on Wiki I see that in addition to the well-known P/T (Permian / Triassic) catastrophe which marks the end of the early synapsid dominance and the famous K/T (Cretaceous / Tertiary) calamity which marked the end of the dinosaurs, it is now thought there was another extinction event, the T/J (Triassic / Jurassic) event. This event is thought to have been slightly less harmful than the K/T event. It marks the disappearance of the non-mammalian therapsids and the large non-dinosaurian members of the archosaur group. As of now they have no evidence of the cause.