Bonatitan

Bonatitan
Temporal occurrence
	Upper Cretaceous ( Campanium to Maastrichtian )
	83.6 to 66 million years
Locations
	Argentina , Allen Formation ( Río Negro );
Systematics
	Dinosaur (dinosauria)
	Lizard dinosaur (Saurischia)
	Sauropodomorpha
	Sauropoda
	Titanosaurs (Titanosauria)
	Bonatitan
Scientific name
	Bonatitan
	Martinelli & Forasiepi , 2004
Art
	Bonatitan reigi;

Bonatitan is a genus of small sauropod dinosaurs belonging to the Titanosauria group thatlived in what is now South Americaduring the late Upper Cretaceous .

So far, two fragmentary skeletons including skull bones are known that were recovered from a site of the Allen Formation in Argentina . The only known species is Bonatitan reigi . Bonatitan was a derived (modern) Titanosauria that is classified within the Saltasaurinae .

features

The Saltasaurinen, with lengths between an estimated 12 and 15 meters, are among the smallest known sauropods. Bonatitan was relatively small even compared to other saltasaurins. The thigh bone of the larger of the two specimens is only 58.5 centimeters long. The limb bones were slender compared to other Saltasaurins such as Saltasaurus and Neuquensaurus . Bonatitan can be distinguished from other genera by various unique features on the skull bones and vertebrae. For example, a pit extending between the pair of parietal bone (parietal) to about supraoccipital the magnum foramen . The vertebral arches of the anterior caudal vertebrae also show deep hollows (fossa) with numerous notches between the zygapophyses .

Systematics

The first descriptors assign Bonatitan to the Saltasaurinae, a group of small, modern, South American titanosaurs. The Saltasaurinae forms together with the Opisthocoelicaudiinae ( Opisthocoelicaudia and Alamosaurus ) the group Saltasauridae. Common features ( synapomorphies ) of Bonatitan with other Saltasaurinen include a crest on the postzygapophyses of the middle caudal vertebrae as well as the lower, forwardly exposed articular knot of the thigh bone (femur).

Finds and naming

Both skeletons were uncovered together in the Bajo-de-Santa-Rosa locality in the Argentine province of Río Negro from the same site. The rocks of the site belong to the Allen Formation , a formation of the Malargüe Group , which is dated from the Campanian to Maastrichtian (Upper Cretaceous). The bones of both specimens were found to be inarticulate and mixed with one another; the assignment to two different individuals was based primarily on differences in size: the holotype specimen was about 20% larger than the other specimen.

The holotype specimen (specimen number MACN-PV RN 821) consists of a complete brain skull , vertebrae (some middle back and tail vertebrae), as well as leg bones (humerus), a metacarpal bone, thigh bone, shin bone (tibia), Fibula, heel bone (calcaneus), and a metatarsal bone). The second skeleton (specimen number MACN-PV RN 1061) also consists of a complete cranial skull and an incomplete cervical vertebra, spoke (radius), ulna (ulna), femur, shin, calcaneus and metatarsal.

The new genus and species was first scientifically described in 2004 by Agustín Martinelli and Analía Forasiepi . The name Bonatitan honors the important palaeontologist José Fernando Bonaparte , who has made a special contribution to his research into the Mesozoic vertebrate fauna of South America. The Artepitheth reigi honors Osvaldo Reig for his contributions to paleontology in South America.

supporting documents

Main source

Augustín G. Martinelli, Analía M. Forasiepi: Late Cretaceous vertebrates from Bajo de Santa Rosa (Allen Formation), Río Negro province, Argentina, with the description of a new sauropod dinosaur (Titanosauridae). In: Revista del Museo Argentino de Ciencias Naturales. NS Vol. 6, No. 2, 2004, ISSN 1514-5158 , pp. 257-305.

Individual evidence

↑ Thomas R. Holtz Jr .: Supplementary Information. to: Thomas R. Holtz Jr .: Dinosaurs. The most complete, up-to-date Encyclopedia for Dinosaur Lovers of all ages. Random House, New York NY 2007, ISBN 978-0-375-82419-7 , online (PDF; 184.08 kB) .
↑ Alejandro Otero: The appendicular skeleton of Neuquensaurus, a Late Cretaceous saltasaurine sauropod from Patagonia, Argentina. In: Acta Palaeontologica Polonica. Vol. 55, No. 3, 2010, ISSN 0567-7920 , pp. 399-426, doi : 10.4202 / app.2009.0099 .

[holtz_08-1] Thomas R. Holtz Jr .: Supplementary Information. to: Thomas R. Holtz Jr .: Dinosaurs. The most complete, up-to-date Encyclopedia for Dinosaur Lovers of all ages. Random House, New York NY 2007, ISBN 978-0-375-82419-7 , online (PDF; 184.08 kB) .

[otero_2010-2] Alejandro Otero: The appendicular skeleton of Neuquensaurus, a Late Cretaceous saltasaurine sauropod from Patagonia, Argentina. In: Acta Palaeontologica Polonica. Vol. 55, No. 3, 2010, ISSN 0567-7920 , pp. 399-426, doi : 10.4202 / app.2009.0099 .