Argentinosaurus

Replica of the reconstructed skeleton of a special exhibition at the Natural History Museum Senckenberg

• Argentina ( Huincul Formation)

• Argentinosaurus huinculensis

Argentinosaurus is a genus of sauropod dinosaur from the group of Titanosauria.

So far, very fragmentary remains have only been known from the early Late Cretaceous ( Cenomanian ) of the Argentine province of Neuquén come.

Argentinosaurus is one of the largest known sauropod, making it one of the largest known land animals on Earth's history - as the current estimate of a length of 30 meters and a weight of about 73 tonnes. The only known species is Argentinosaurus huinculensis.

Features

So far, only few bones have been found. The holotype material includes three front and three rear dorsal vertebrae, the lower portions of the vertebral bodies of five sacral vertebrae, most of the right sacral ribs, the bulk of a fragmented dorsal rib and the right shin (tibia) with a. Furthermore, Argentinosaurus was an incomplete thigh bone (femur ) attributed ( copy number MLP -DP 46- VIII -21 -3), which has a length of 1.18 meters. A total of 10 % of the entire skeleton are thus in the fossil record.

The vertebrae are up to 1.59 meters in height, measured from the spinous processes of the vertebrae to the bottom, while the vertebrae show diameter of approximately 50 centimeters. The tibia is about 1.55 meters long.

An early reconstruction by Gregory Paul estimated Argentinosaurus to a length of 30 to 35 meters and a weight of 80 to 100 tons. Other researchers base their size estimates the physique better known, related genera to reason and assume that Argentinosaurus showed similar proportions. So used Carpenter (2006) the complete Saltasaurus known as the reference and estimated Argentinosaurus at 30 meters in length. Weight estimates are generally more difficult and will be less frequent. Researchers to Mazzetta (2004) calculated, however, that the weight was 60-88 tons, 73 tons and give as the most probable value, which makes it the heaviest Argentinosaurus, known by relatively good sauropod fossils.

The vertebrae of sauropods were additional mechanical fasteners which Hyposphen - Hypantrum connections. These compounds stabilized the spine and thus probably supported the gigantism of sauropods, but at the same time a restricted spinal mobility. In most Titanosauria including Argentinosaurus these fasteners have been lost in favor of a more flexible spine. In Argentinosaurus and in similar form in Epachthosaurus secondarily novel compound elements are analogous to the Hyposphen - Hypantrum connections developed; probably as a result of increasing body size.

Argentinosaurus can be distinguished by the novel compound elements of the vertebrae (see above) and by the tubular fins of other genera.

System

The position of this genus within the Titanosauria is controversial. The describer ( Bonaparte and Coria, 2003) associated with Argentinosaurus Andesaurus within their own family Titanosaurier original one, the Andesauridae which should face the more advanced Titanosauridae. Today the Andesauridae is considered paraphyletic and hence invalid. Also Upchurch and colleagues ( 2004) see Argentinosaurus as a primitive representative of the Titanosauria, and classify him outside the Lithostrotia ( = Titanosauridae ). Curry Rogers ( 2005), however, sees Argentinosaurus as representatives of a group of very advanced Titanosauria, the Opisthocoelicaudiinae. In this group, it summarizes Argentinosaurus, Isisaurus, Alamosaurus, Opisthocoelicaudia and Antarctosaurus together.

History of discovery and naming

The fossils were collected by staff of the museum Carmen Funes within the farm Las Overa in the City Plaza Huincul. While initially only a shin was excavated, the remaining fossils were recovered in the summer of 1989.

The site belongs to the Huincul formation, a layer member of the Río Limay - subgroup of the Neuquén Group. Earlier this rock unit was subordinated as Huincul member of the Río Limay - formation.

Argentinosaurus was described in 1993 by the Argentine paleontologist José Fernando Bonaparte and Rodolpho Coria first time scientifically. The name Argentinosaurus (Latin for " Argentina lizard" ) has the country Argentina, during the second part of the species name, huinculensis, has the City Plaza Huincul where the fossils were found.