Amazonsaurus and the Itapecuru dicraeosaurid

[Jose Ignacio Ruiz-Omeñaca <jigruiz@unizar.es>]

>Thanks to both Mickey Mortimer and Jose Ignacio Ruiz-Omenaca for sending me 
>the Amazonsaurus PDF; now all I have to do is find time to read it.  I was 
>under the impression that Amazonsaurus was the same animal mentioned the SVP 
>2002 abstract "A New Sauropod from the Aptian-Albian of Brazil and its 
>phylogenetic relationships" I was apparently wrong, seeing as how this 
>abstract mentions an axis and assigns the sauropod to Dicraeosauridae.  Does 
>anyone have further information on this other Itapecuru taxon?

I thik that "the Itapecuru specimen" and Amazonsaurus maranhensis are the same 
taxon.

"The Itapecuru specimen is known from a few, but diagnostic postcranial 
skeleton comprising several incomplete vertebrae, isolated centra, neural 
spines, chevrons, both scapulae and a complete ilium" (Carvalho & Avilla, 
2002), 

and the holotype of Amazonsaurus maranhensis has "two dorsal neural spines; two 
dorsal centra; neural spine of anterior caudal vertebra; one mid caudal 
vertebra; one mid-posterior caudal vertebra; two posterior caudal vertebrae; 
eight chevrons; an ilium; a partial pubis; and three ribs" (Carvalho et al., 
2003).

Perhaps the "very elongated neural spine of the axis" of  Carvalho & Avilla 
(2002) has been reidentified as the "neural spine of anterior caudal vertebra" 
figured in Carvalho et al. (2003), and the scapulae of  Carvalho & Avilla 
(2002) could be the two dorsal neural spines of  Carvalho et al. (2003), or 
could be not from a sauropod but any othed dinosaur. It should be noted that 
Amazonsaurus´ bones were associated with  turtles and crocodyle and theropod 
teeth, so many taxa fossilized together in the "proximal fluvial mouthbar 
deposits" of the locality.

Hope this helps.

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Jose Ignacio Ruiz-Omeñaca
Departamento de Ciencias de la Tierra
Area de Paleontologia
Universidad de Zaragoza
E-50009 ZARAGOZA, SPAIN

tel: (+34) 976 761000 ext. 3160
fax: (+34) 976 761106
e-mail: jigruiz@unizar.es
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