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Re: DINOSAUR digest 3466



> Date: Tue, 31 Jan 2006 09:54:39 +0100
> From: Jose Ignacio Ruiz-Omeñaca <jigruiz@unizar.es>
> Subject: Paleoneurological evidence against a
> proboscis in the sauropod
>  dinosaur Diplodocus
> To: dinosaur@usc.edu
> 
> A new paper of my colleague and excellent
> paleontologist Fabien Knoll:
> 
> Fabien Knoll, Peter M. Galton and Raquel
> López-Antoñanzas. Paleoneurological evidence against
> a proboscis in the sauropod dinosaur Diplodocus.
> Geobios, In Press, Corrected Proof, Available online
> 20 January 2006
> 
> The dinosaur Diplodocus has a single, relatively
> large external bony narial orifice that is
> positioned far back between the orbits. In some
> mammals, such as elephants and tapirs, the caudal
> position of the narial opening is associated with a
> proboscis, so it has been suggested that Diplodocus
> possibly also had a trunk. In elephants, the facial
> nerve is large as it emerges from the brain. A
> branch of this nerve and a branch of the trigeminal
> nerve unite to form the proboscidial nerve that
> supplies the muscles of the powerful and complex
> motor system of the trunk. In contrast to the
> situation in modern elephants, the absolute as well
> as the relatively small size of the facial nerve in
> Diplodocus (deduced from an endocranial cast)
> indicates that there is no paleoneuroanatomical
> evidence for the presence of an elephant-like
> proboscis in this genus.

What about tapir skull? Or Markauchenia, which is also
supposed to have trunk? 

Jerzy 

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