New sauropod refs: Rinconsaurus & Amygdalodon

[bh480@scn.org]

New sauropod refs
From: Ben Creisler
In case these refs have not been mentioned here:

Calvo, J.O. & B.J.G. Riga, 2003. Rinconsaurus caudamirus 
gen. et sp nov., a new titanosaurid (Dinosauria, 
Sauropoda) from the Late Cretaceous of Patagonia, 
Argentina. REVISTA GEOLOGICA DE CHILE 30 (2):333-353 (DEC 
2003)
Rinconsaurus caudamirus gen. et sp. nov. (Dinosauria, 
Sauropoda) is a new and slender Titanosauridae. The 
specimens come from the Upper Cretaceous strata of the Rio 
Neuquen Formation at Rincon de los Sauces, Neuquen 
Province, Patagonia, Argentina. The remains include 13 
articulated caudal vertebrae and disarticulated cranial, 
cervical, dorsal and appendicular materials. These fossils 
belong to three individuals, two adults and one juvenile. 
This new species is characterized by the following 
association of autapomorphies: (1) neural spines in mid-
anterior dorsal vertebrae inclined posteriorly more than 
60 degrees with respect to the vertical, (2) middle caudal 
vertebrae with bony processes that support the articular 
surfaces of postzygapophyses, and (3) procoelous posterior 
caudal centra with intercalation of a series of 
amphicoelous-biconvex or amphicoelous-opisthocoelous-
biconvex centra. A cladistic phylogenetic analysis placed 
Rinconsaurus in the family Titanosauridae. Within 
Titanosauridae (Rinconsaurus + Aeolosaurus) is considered 
a sister group of the clade (Opisthocoelicaudia + 
(Alamosaurus + (Neuquensaurus + Saltasaurus))). 
Rinconsaurus caudamirus has preserved short articulated 
posterior caudal series with amphicoelous, opisthocoelous 
and biconvex centra. This unusual morphology represents 
the first such occurrence in sauropod dinosaurs. From the 
systematic point of view, this discovery is important 
because Titanosauridae were traditionally defined, among 
other characters, by strongly developed procoelia in their 
caudal vertebrae.
Calvo, JO: jocalvo40@yahoo.com.ar; Riga, BJG: 
bgonriga@lab.cricyt.edu.ar

This is the follow up to:
Gonzalez Riga and Calvo, 2001. A new genus and species of 
titanosaurid sauropod from the Upper Cretaceous of Rincon 
de los Sauces, Neuquen, Argentina. JVP 21(3) 55A. 

Rauhut, O., 2003. Revision of Amygdalodon patagonicus 
Cabrera, 1947 (Dinosauria, Sauropoda). Mitteilungen aus 
dem Museum fuer Naturkunde in Berlin: Geowissenschaftliche 
Reihe 6:173-181.

AB: The type material of the oldest known sauropod 
dinosaur from South America, Amygdalodon patagonicus, from 
the Cerro Carnerero Formation (Toarcian-Bajocian) of 
Chubut province, Argentina, is reviewed. The material 
includes elements of at least two individuals plus a 
remain of another, indeterminate vertebrate, and a 
posterior dorsal vertebra is designated as the lectotype 
of Amygdalodon. All of the sauropod material originally 
referred to this species represents very basal, non-
neosauropodan eusauropods. Amygdalodon is the only South 
American evidence for a probable Early to early Middle 
Jurassic global dispersal of basal eusauropodan sauropods.