Yesterday we looked at the reduction of the postorbital and postfrontal in basal cynodonts and their predecessors among the gorgonopsids and theerocephalians. And for those who got there early, a late addition found the missing taxon I was looking for.
Today we’ll look at data that appears great, but a little experience tells you it’s not all there. In Sauroctonus (Fig. 1) it looks like we have a squamosal contributing to the base of the postorbital bar. But sister taxa don’t do that.
Sure, the easy answer is to go visit the specimen
But here I’ve done what I want to do without weeks of planning, a few day’s worth of jetting around, and thousands of dollars in expenses. Does this problem move this taxon up or down the tree a node or two? Doubtful, so why not go with what you’ve got?
Yes, there’s great data and terrible data out there. You have to trust a single source of data, but when given the opportunity to make comparisons, go ahead and test one against the other and their sisters. Sometimes the data is a poor half-a-century-old drawing. Sometimes you take what you can get and make corrections later.
Keep pushing. It will all work out in the end.
Bystrow AP 1955. A gorgonopsian from the Upper Permian beds of the Volga. Voprosy Paleont., 2: 7-18.
Gebauer EVI 2007. Phylogeny and Evolution of the Gorgonopsia with a Special Reference to the Skull and Skeleton of GPIT/RE/7113 (‘Aelurognathus?’ parringtoni). PhD Dissertation, Eberhard-Karls University at Tübingen. Online here.