Re: New Titanosaur (Maxakalisaurus) from Brazil

[Matias Soto <soto@adinet.com.uy>]

Nope, Andesauridae has been recognized as a paraphyletic assemblage of basal 
titanosaurs. Of the "andesaurids" you mentioned,  *Andesaurus* is the single 
non-titanosaurid titanosaur. In fact, one of the purported synapomorphies 
(presence of hyposphene-hypanthrum) has been shown to be lacking in 
*Argentinosaurus* (i.e., *Argentinosaurus* shares with other 
"titanosaurids"/lithostrotians, or derived titanosaurs, the character-state 
"hyposphene-hypanthrum absent)". *Epachthosaurus*, in turn, it is one of the 
most basal titanosaurid with procoelous mid and posterior caudal vertebrae 
(differing in this respect from *Andesaurus*, whose mid and posterior 
caudals are amphyplatyan). Indeed, it was chosen by Salgado (2003)
as a reference taxa in his restricted node-based definition of 
Titanosauridae (= Epachthosaurus sciuttoi + Saltasaurus loricatus).
Hope this helps,

Matías Soto

----- Original Message ----- 
From: "Jamie Stearns" <stearns5@cox.net>
To: <dinosaur@usc.edu>
Sent: Monday, August 28, 2006 9:28 PM
Subject: Re: New Titanosaur (Maxakalisaurus) from Brazil


> Well, I see they took the time to classify this one somewhat, as I found 
> titanosaur classification to be pretty difficult due to the number of 
> described but still "incertae sedis" taxa out there. As far as I could 
> tell, there were a number of basal titanosaurs, then Andesauridae which 
> includes Epachthosaurus, Andesaurus, and Argentinosaurus (Is this still 
> valid?), a proposed family of titanosaurs noted for (I think) amphicoelous 
> vertebrae which includes Adamantisaurus, Rinconsaurus, Gondwanatitan, 
> Laplatasaurus and possibly the original *Titanosaurus indicus*, the 
> inclusion of which would make this the Titanosauridae, and finally the 
> saltasaurids. I don't know exactly why the position of Aegyptosaurus is 
> still uncertain, as it's been known for a long time now and Stromer most 
> likely figured some of the (apparently somewhat complete) material in his 
> papers somewhere. Another question: Is a skull known for Argentinosaurus? 
> Many sources say there is no skull known, but I've also heard reports that 
> a prospector named Daniel Eseisa had found the skull. The one on the 
> Fernbank Museum's impressive restoration appears to be similar to a 
> somewhat longer-faced Camarasaurus.
>
> Moving on, I see another Diplodocus-like head has been added to this one. 
> Was it preserved at all, or was it simply based on Rapetosaurus?
>
>
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