The last of Peters' (2000) "key taxa" to placing pterosaurs outside Archosauriformes is Sharovipteryx. Another taxon which was originally poorly illustrated and described, Gans et al. (1987) did a mediocre job redescribing it, and good photos are available of some areas. Unwin et al. (2000) provide some new information. Like Longisquama, Peters' imagination is at play in the 2000 paper. The forelimbs were not exposed at the time and the skull is in dorsal view, not ventral.
After coding, Sharovipteryx joins the other discussed taxa somewhere basal to Erythrosuchus. The topology is- (Sharov(Cose,Lango)(Longi(Valle,Megalanc))). As before, 13 more steps are needed to take pterosaurs out of Archosauriformes. They're still closest to simiosaurs, then Longisquama, with Sharovipteryx the next outgroup.
Next up, the pterosaurs themselves.
Mickey, could you draw this onto Nesbitt's tree? It would help a lot.ReplyDelete
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Most parsaimonious tree is-ReplyDelete
...`--more derived archosauriforms
Wow, does that comment ever need a fixed-width font :-)ReplyDelete
Very clever of Blogspot to reject comments that contain the [pre] or even [tt] tag. One more reason to be on Wordpress instead!
Yup. You may be able to see the deleted remains of my previous comment where I tested if more than one spaces actually work (they don't). Maybe if I use three periods below each plus sign...ReplyDelete
....`--more derived archosauriforms