Czerkas and Feduccia disconnect birds and dinos

Figure 1. Reconstruction of Scansoriopteryx with possible feather extent by Stephen Czerkas. Good thing that second branch or telephone wire is available for balance!

Figure 1. Reconstruction of Scansoriopteryx with possible feather extent by Stephen Czerkas. Good thing that second branch or telephone wire is available for balance!

A new paper by Czerkas and Feduccia
attempts to unlink birds with dinosaurs and to link birds with some unspecified archosaur by their reexamination of Scansoriopteryx, a tiny Chinese fossil of the Jurassic. Much has already been said about this paper — all negative.

Czerkas and Feduccia report the “absence of fundamental dinosaurian characteristics,” but do not do so with phylogenetic analysis, which would have nested their study subject somewhere else that they could support, but can’t. They seem stuck in a trees-down vs. ground up battle when plenty of ground-dwelling dinosaurs seem fully capable of climbing a tree by grappling or simply by running up a vertical trunk bipedally, as some modern birds do (any Dial reference below). Their illustration (Fig. 1) seems to say that whether bird or dinosaur or non-dinosaur, Scansoriopteryx was not capable of standing balanced on its (apparently splayed?) hind limbs, despite the fact that it’s forelimbs appear poorly designed for walking. They’ve been accused of LarryMartinizing and it seems they have indeed been doing so. For those interested, Larry Martin preferred to discuss individual characters rather than suites of characters of a sort used in phylogenetic analysis.

I can’t buy into their particular heresy.
There’s no support for it. We need to see details and analyses. And they need to present their best alternative candidate among the non-dinosaurian archosaurs out there as a sister to Scansoriopteryx. 

The irony here
is that the same sort and style of argumentation is being used to support a pterosaur/archosaur connection by the same set of paleontologists who support the dino/bird connection. By that I mean, they present no archosaurian candidates that more closely match pterosaurs than our own favorites: the lepidosaur, tritosaur, fenestrasaurs.

So, if you’re a finger pointing paleontologist, be careful. Don’t fall into  that same trap.

References
Czerkas SA and Feduccia A 2014. Jurassic archosaur is a non-dinosaurian bird, Journal of OrnithologyDOI: 10.1007/s10336-014-1098-9
Dial KP, Jackson BE and Segre P 2008.  A fundamental avian wing-stroke provides a new perspective on the evolution of flight. Nature (online 23 Jan 08)
Padian K and Dial KP 2005. Could the “Four Winged” Dinosaurs Fly?  Nature: 438:E3-5.
Dial KP, Randall R and Dial TR 2006. What use is half a wing in the evolution of flapping flight? BioScience 56: 437-445.
Tobalske BW and Dial KP 2007. Aerodynamics of wing-assisted incline running. J. Exp. Biol. 210:1742-1751.
Bundle MW and Dial KP  2003. Mechanics of wing-assisted incline running.  J. Exp. Biol., 206:4553-4564.
Dial KP 2003.  Evolution of avian locomotion: Correlates of body size, reproductive biology, flight style, development and the origin of flapping flight. Auk 120:941-952.
Dial KP 2003. Wing-assisted incline running and the evolution of flight.  Science 299:402-404.
Read more at: http://phys.org/news/2014-07-declassify-dinosaurs-great-great-grandparents-birds.html#jCp

 

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2 thoughts on “Czerkas and Feduccia disconnect birds and dinos

  1. “Good thing that second branch or telephone wire is available for balance!”

    No, I think it’s doing uneven-bars gymnastics. Doubt it would get a ten, though.

  2. Kevin Padian’s suggestion that Microraptor evolved its flight feathers for display is one of the most ludicrous claims that an evolutionary biologist have ever made. It is clear that many of these so-called feathered dinosaurs are in fact hidden birds from China. If Deinonychus ran up a tree trunk, and loses its balance, then it would end up being a grease spot on the ground. The claim that flight evolved from the ground up is even more ludircrous than the idea that a ground dwelling theropod would evolve flight feathers on its legs for display. Such feathers slow the animal down. Unless the display feathers are so effective that dinosaurs who walk by will throw the display artists some scraps of meat, Microraptor would starve to death because it is too slow to catch anything to eat.

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