[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

New South American dinosaur news



This is from a while back, but I don't seem to recall it being mentioned previously n the list.  On http://www.paleonet.com.ar/ you can download abstracts from the XVI Jornadas Argentinas de Paleontología de Vertebrados that occured on May 15-17.  Most are in Spanish, but they do include several interesting dinosaur papers.  Besides lots of egg and footprint stuff, we have...
 
Coria, 2000. New findings of dinosaurs in the Rio Neuquen Basin.
 
Basically lists the dinosaurs known from the Neuquen Group.  Nothing new, but Ilokelesia is mentioned as well as Coria and Chiappe's new abelisaurid, which is described later.....
 
Bertini, Santucci, Ribeiro and Arruda-Campos, 2000. Aeolosaurus (Sauropoda: Titanosauria) from Upper Cretaceous of Brazil.
 
This sums up all the occurences of Aeolosaurus.  The most intriguing comment is that they synonymize Gondwanatitan with Aeolosaurus based on the anterodorsally projected neural spine on proximal caudal vertebrae and "other appendicular characters".
The original description of Gondwanatitan notes however, that the two genera differ in several features:
- sixth sacral centrum with concave posterior articular surface in Gondwanatitan
- heart-shaped posterior articular surfaces on proximal and mid caudal centra in Gondwanatitan
- prominent lateral ridge on basal part of mid caudal neural arch in Gondwanatitan
- large articulation of the prezygopophyses in Aeolosaurus
- lateral tuberosity present on ischium in Gondwanatitan
- iliac peduncle of ischium less expanded in Gondwanatitan
- medial ischiac plate less expanded in Aeolosaurus
- more slender humerus in Aeolosaurus
Thus, I do not accept the synonomy of thse two genera.
 
Coria and Chiappe, 2000. New abelisaurid theropod from the Rio Colorado Formation (Late Cretaceous) of Neuquen Province.
 
This describes the new, nearly complete abelisaurid mentioned in connection to Ilokelesia earlier on the list.  It was discovered in Auca Mahuevo, where all the titanosaurid embryos were described two years ago.  It is the sister group of Carnotaurus based on cranially oriented processes on the cervical epipophyses and hyposphene-hypantrum articulations in the proximal caudal vertebrae.  There are also shared characters with an ambiguous distribution among abelisaurids (due to poor postcranial remains) including lateral frontal prominences; large coracoid; humerus with large hemispherical head; very short radius and ulna.  It is distinguished from Carnotaurus by a lower snout and antorbital fenestra; a promaxillary fenestra showing laterally; the presence of prominences, not horns, on the frontals; chevrons with heamal canal; reduced coracoid process; other forelimb characters I can't read in Spanish.  Thus, it is a new taxon.
 
Diaz, Vargas, Rubilar, Suarez, Cacares and Kellner, 2000. Cretaceous dinosaur locality at the Atacama Desert, Northern Chile.
 
A new Chilean locality with two incomplete titanosaur skeletons, based on procoelous distal caudals.  This suggests a Late Cretaceous age for the site.
 
Gonzalez Riga and Casadio, 2000. New remains of Hadrosauridae (Ornithischia) from the Allen Formation, Pampas Province, Argentina.
 
Hadrosaurine elements (cervical and dorsal vertebrae, scapular fragments, coracoids, femur, phalanges) from the Allen Formation of the Falkland Islands.  The specimen exhibits opisthocoelous, heart-shaped cervical centra, cervical neural arches with robust postzygopophyses, reduced neural spines and amphiplatyan dorsal centra.  The large dorsal centra are hexagonal.  Hadrosaurid characters are also seen in the scapulae, coracoids and phalanges.  The short dorsal neural arches with vertically oriented diapophyses ally it with hadrosaurines.  Although too incomplete for specific determination, it is not synonymous with Kritosaurus? australis.
 
Vargas, Suarez, Rubilar and Moreno, 2000. A titanosaurid vertebra from Pichasca, Formation La Vinita (Late Cretaceous), IV Region, Northern Chile.
 
The La Vinita Formation is Maastrichtian and has produced the anterior half of a titanosaurid posterior dorsal vertebrae (MNHN 387, centrum width 35 cm, centrum height 25 cm).  The pleurocoels are elongate and there are no hyposphenes.
 
That's all the dinosaurian osteological articles.  I just got the papers on Charonosaurus and Isanosaurus, so I'll be writing details segments on them soon, but college really takes time out of the day.
 
Mickey Mortimer