the importance of Quianosuchus

[David Peters <davidrpeters@earthlink.net>]

I ran across* Quianosuchus yesterday at the Hairy Museum of  
Paleontology and wondered what it was and why nobody had ever  
mentioned it before on the dino list.

It's got a long rostrum, a dorsally placed naris and an unusually  
broad scapula. Neural spines are high. Neck is long. Hands are  
missing. Feet are small and all five toes seem to be represented,  
but, unfortunately, not in their entirety.

Plugging what is shown online in the excellent line drawing,  
Quianosuchus nests as the sister taxon to Ticinosuchus, which begets  
aeotosaurs. Their common ancestor was a sister to Vjushkovia. Q also  
nests just below Turfanosuchus, the last known common ancestor of  
crocs and dinos. That makes Turfanosuchus THE basal archosaur, or  
very close to it. Quianosuchus ain't that far away and it's more  
completely known.

With Quianosuchus, the lineage leading toward dinosaurs has just  
gotten bushier. And its nice to know that none of the metatarsals are  
reduced in diameter. That little fact has big implications for  
Irmis's so-called "dinosauromorphs."

More brewing.

David Peters
St. Louis




* http://www.hmnh.org/archives/category/mesozoic/triassic/page/2/