アストルゴスクス（ブグティワニ）の吻部形状 : 残る疑問点 （英文雑記）

Bugti Croc, 'only comparatively short snouted'??

by the Saber Panther

Astorgosuchus, a still very elusive giant crocodyloid from the Oligocene Pakistan is described(Martin et al., 2019) as a typically short snouted, remarkably broad headed crocodilian, clearly different from tomistomines in these regards, yet, its mandible symphysis (frontal tip of the lower jaw) extends more posteriorly than in most Crocodilus of today, to the first seventh teeth.

 

An extended mandibular symphysis I gather, is generally a character of longirostrine forms such as Tomistoma and rarely observed in relatively short snouted taxa(but I may be wrong). Asiatosuchus may be one of exceptions, with whom Astorgosuchus is considered to have shared some similarities.

 

I have to admit that I'm not that much familiar with reptiles(although I love them, especially crocodilians extinct and extant), so the following may be just baseless suspicions, nonetheless I find it somewhat perplexing : does this mean that the Bugti croc is notable because of having a short, robust rostrum(it's actually described as such in the paper) while retaining an extended symphysis, 'a combination' rarely observed among other crocodyloids, or, it was short snouted 'only comparatively so', in compared with truly longirostrine forms.

 

If the latter was the case, Astorgosuchus may not have been short snouted as, say C. porosus, perhaps more like the Orinoco crocodile(?) whose rostrum appears much elongated, but definitely not so as in Tomistoma.

True, you can find the cranial restoration of Astorgosuchus in the internet which depicts a silhouette of typically broad and shortened rostrum, yet the fossils appear to me too fragmentary to be definitively construed whether it was really that massive or otherwise.

The way you interpret it could change the result a lot！

 

Here's the restoration based on the 'first' interpretation. (original image)

 

Then the restoration based on the 'latter' interpretation. (modifying its jaws slightly thinner and elongated)

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