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Re: Eosinopteryx, new paravian from China

I cannot overemphasize, having examined a whole bunch of claws, that using 
the bony unguals to estimate the curvature of the living claw is extremely 
unreliable, and definitely will often give errant results, and should never, 
ever be done. I can also tell, just looking at the keratin sheath of the 
Eosinopterx claws, that they are very straight, and unless something is very 
wrong with the specimen they are much more indicative of terrestrial than 
arboreal habits. This makes sense considering the short arms. 

As for this primitive Jurassic beast being a troodont, that is a real 
stretch. Am not even sure it is an avepectoran.

In a message dated 1/23/13 6:13:37 PM, df9465@yahoo.co.uk writes:

<< I just measured the outer curvature of the D-IV ungual. I used the 
larger photo available from Andrea Cau. The photo is fuzzy when zoomed in, so 
making out the actual tip is estimated, and might be underestimating. Plus, if 
the ungual is even slightly oblique (with respect to the photo), then the 
curvature value will be decreased. Hence the following value is a minimum.

Outer curvature for D-IV-5 is 69.1 degrees.

This compares with values for D-IV-5's:

Deinonychus 91.6; 65.9; 87

Saurornitholestes 90.6

Bambiraptor 81.7, 85.5

velociraptor 57.1

Cryptovolans 112

Microraptor 73.74

Sinornithoides 88.8

Troodon 75.4

tanycolagreus 49.5

Allosaurus 81.4 >>