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Re: Asilisaurus kongwe, the Oldest Avian-line Archosaur and the Early Diversification of Ornithodira



Okay, the Avian-line problem is understood.

Asilsaurus is Anisian, older than anything dinosaurian and, surprisingly, way 
older than Silesaurus. 

The dating of the age of the Manda beds >might< be a problem. But maybe not. 

The contemporary Xinlingzhen formation produced Lotosaurus, a silesaurid 
relative (not tested by Nesbitt's group).

As Nesbitt's group indicate on their temporal chart, the diversification was 
earliest Middle Triassic.  Probably so. That does leave a long ghost lineage 
for dinos. And a long period of not much evolution for Silesaurids. 

Questions:

If Nesbitt's group and others are so keen on keeping pterosaurs with dinosaurs, 
why don't they include Cosesaurus (Middle Triassic), Sharovipteryx and 
Longisquama (Late Triassic) a couple of very dinosaurian/pterosaurian-looking 
taxon? 

And for that matter all the drepanosaurids and Jesairosaurus? 

And  if Lagerpeton, why not Chanaresuchus and Tropidosuchus (same kind of 
pedes)? Surprisingly proterochampsids and phytosaurs  often nest just outside 
the Ornithodira (don't ask me why). 

And then throw in Scleromochlus (a forgotten, in this case, "ornithodiran"). 

And just to keep things interesting Pseudhesperosuchus, Turfanosuchus, 
Trialestes and Gracilisuchus, a couple of bipedal croc-types to see if 
bipedalism was shared or convergent?

It gets more interesting the less pre-selection bias is present.

David Peters
St. Louis