Aeolosaurus

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Aeolosaurus
Artistic reconstruction of Aeolosaurus

Artistic reconstruction of Aeolosaurus

Temporal occurrence
Upper Cretaceous (Upper Campanium to Lower Maastrichtian )
76.4 to 69.9 million years
Locations
Systematics
Dinosaur (dinosauria)
Lizard dinosaur (Saurischia)
Sauropodomorpha
Sauropoda
Titanosaurs (Titanosauria)
Aeolosaurus
Scientific name
Aeolosaurus
Powell , 1987
species
  • Aeolosaurus rionegrinus ( type )
  • Aeolosaurus colhuehuapensis (Casal et al. , 2007)
  • Aeolosaurus maximus ( Santucci et al. , 2011)

Aeolosaurus is a genus of sauropod dinosaurs from the Titanosauria group that lived in the Upper Cretaceous South America. The fossils come from different sites in Argentina and Brazil and can be dated to the late Campanian and early Maastrichtian .

So far, three are types described: The type species aeolosaurus rionegrinus , type 2007 described aeolosaurus colhuehuapensis well as the type described in 2011 aeolosaurus maximus . Sometimes Aeolosaurus is combined with Gondwanatitan in the Aeolosaurini group.

features

Aeolosaurus , like all sauropods, was a herbivore with a long neck and tail, reaching an estimated length of about 15 meters. Like some other titanosaurs, Aeolosaurus had osteoderms (skin bone plates). Two osteoderms were discovered in connection with Aeolosaurus remains in the Allen Formation - the better preserved of these two finds is oval and measures 15 centimeters in diameter. Two other osteoderms come from a quarry of the Marília Formation , which also contained the bones of Aeolosaurus , and can therefore possibly also be assigned to this genus. While one of these osteoderms is oval, the other shows a D-shape and tapers towards the top. Titanosaur osteoderms are only ever found in a few specimens. This could indicate that titanosaurs only carried a few osteoderms and that the latter - contrary to what was previously assumed - did not serve as a defense against predators .

According to Upchurch and colleagues (2004), this genus can be distinguished from other genera by the following characteristics ( autapomorphies ): The upper (dorsal) front edge of the spinous processes of the middle caudal vertebrae is extended towards the front and thus forms an overhang over the front area of ​​the vertebral bodies . Furthermore, the upper arm bone (humerus) shows a clear knob-like elevation on the deltopectoral ridge . The anterior articular processes ( prezygapophyses ) of the caudal vertebrae were long and showed very wide connecting surfaces.

Systematics

The systematic position within the Titanosauria is controversial. Initially, the genus was classified as a relative of Titanosaurus within the Titanosaurinae - this name is currently considered invalid by many researchers. Upchurch and colleagues (2004) classify Aeolosaurus within the Lithostrotia , which includes all more advanced titanosaurs except for a few primitive species.

Some researchers put Aeolosaurus and the closely related Gondwanatitan in a separate group - the Aeolosaurini . The genera Rinconsaurus , Panamericansaurus and Maxakalisaurus are also occasionally classified within the Aeolosaurini . Santucci and colleagues (2011) come to the conclusion that Panamericansaurus , Maxakalisaurus and Rinconsaurus were more original representatives of the Aeolosaurini than Aeolosaurus and Gondwanatitan . The aeolosaurini can be differentiated from other titanosaurs, among other things, by vertebral arches of the middle caudal vertebrae, which extend forward beyond the front edge of the vertebral bodies.

History of discovery, species and naming

Thigh bones (femur) from Aeolosaurus from Brazil

This genus was first described scientifically in 1987 by Jaime Powell . Powell description is based on fragmentary remains from the Angostura Colorada formation Province, Argentina Rio Negro - seven cervical vertebrae, the two shoulder blades partially preserved, two humerus, five metacarpals , the right shinbone (tibia) and fibula (fibula) and an anchor leg (Astragalus) . The genus name Aeolosaurus ("Aiolos' lizard") refers to the god of the winds of Roman and Greek mythology , Aiolos (Latinized Aeolus ), which is an allusion to the strong winds in the Patagonia region. The species name rionegrinus indicates the place where it was found.

In the following years Aeolosaurus were attributed further finds. Salgado and Coria (1993) assigned this genus to fossils from the lower limb of the Allen Formation , which Argentine paleontologists discovered in June 1989 in the Salitral Moreno site near General Roca in Río Negro. The fossils from multiple individual finds and include five vertebra, ulna, radius (radius), a metacarpal bone, pubis (pubic), ischium (ischium) and two osteoderms (skin bone plates) with a. Salgado and Coria suspect that these finds could belong to another species of Aeolosaurus , as the caudal vertebrae differ from the Aeolosaurus rionegrinus type by shorter and more robust prezygapophyses and differently positioned postzygapophyses . However, due to the incomplete fossil record, they decided not to name a new species and referred to the finds as Aeolosaurus sp.

A partial skeleton from the Los Alamitos Formation, also from Río Negro, was described by Salgado and colleagues (1997) and consists of four caudal vertebrae, two breast bones (sternum), a left humerus, two metacarpal bones, a partial left thigh bone, one left tibia, a fibula, an ankle bone and four metatarsal bones; a series of 15 caudal vertebrae was also discovered.

In 2000, 2001 and 2002, fossils from the Marília Formation near Uberaba in Brazil were assigned to the genus Aeolosaurus . In the same quarry that also housed the bones, osteoderms were found that resemble the two already known Aeolosaurus osteoderms and could therefore also belong to Aeolosaurus . Additional Aeolosaurus fossils from the Marília Formation were described in 2008. These finds include a right coracoid (coracoid), two vertebrae, a possible phalanges and a left tibia and other, unidentifiable fragments with one. Since these bones were found in an area of ​​only ten square meters, they could have belonged to the same individual.

In 2007, a series of 21 caudal vertebrae, which are still anatomically connected, were described as a new Aeolosaurus species - Aeolosaurus colhuehuapensis . This series of vortices comes from an island currently rising out of the water in Colhué Huapi , one of the largest lakes in Argentina, in the province of Chubut . The site belongs to the Bajo Barreal Formation . These vertebrae differ from the Aeolosaurus rionegrinus type in that they have deep pits (fossa) between the transverse processes and at the base of the spinous processes. The species name colhuehuapensis refers to Lake Colhué Huapi in Chubut, where the fossils were found.

In 2011, Rodrigo M. Santucci and colleagues described a third species, Aeolosaurus maximus . This species is based on a fragmentary skeleton that was recovered in 1997 and 1998 by paleontologists at the Museu de Paleontologia de Monte Alto from the layers of the Adamantina Formation in the Brazilian state of São Paulo . This skeleton consists of cervical vertebrae, caudal vertebrae, ribs and leg bones, with the humerus, thigh bones, cervical vertebrae and anterior caudal vertebrae found in their original anatomical position.

Individual evidence

  1. ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 208, online .
  2. ^ A b c d e Rodrigo M. Santucci, Antonio C. de Arruda-Campos. A new sauropod (Macronaria, Titanosauria) from the Adamantina Formation, Bauru Group, Upper Cretaceous of Brazil and the phylogenetic relationships of Aeolosaurini. In: Zootaxa . Vol. 3085, 2011, pp. 1–33, digital version (PDF; 2.09 MB) .
  3. ↑ a b c d Renato Pereira Lopes, Francisco Sekiguchi de Carvalho Buchmann: Fósseis de titanossauros (Dinosauria, Sauropoda) de um novo afloramento no Triângulo Mineiro, sudeste do Brasil. In: Revista Brasileira de Paleontologia. Vol. 11, No. 1, 2008, ISSN  1519-7530 , pp. 69-72, digital version (PDF; 1.65 MB) .
  4. ↑ a b c d e Paul Upchurch , Paul M. Barrett , Peter Dodson : Sauropoda. In: David B. Weishampel , Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 259-324.
  5. ↑ 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) .
  6. ↑ a b c Leonardo Salgado , Rodolfo A. Coria : El genero Aeolosaurus (Sauropoda, Titanosauridae) en la formación Allen (Campaniano-Maastrichtiano) de la Provincia de Río Negro, Argentina. In: Ameghiniana . Vol. 30, No. 2, 1993, pp. 119-128, online .
  7. ↑ Michael D. D'Emic, Jeffrey A. Wilson, Sankar Chatterjee : The titanosaur (Dinosauria: Sauropoda) osteoderm record: review and first definitive specimen from India. In: Journal of Vertebrate Paleontology. Vol. 29, No. 1, 2009, ISSN  0272-4634 , pp. 165-177, doi : 10.1671 / 039.029.0131 .
  8. ↑ Jeffrey A. Wilson, Dhananjay M. Mohabey, Shanan E. Peters, Jason J. Head: Predation upon Hatchling Dinosaurs by a New Snake from the Late Cretaceous of India. In: PLoS Biol . Vol. 8, No. 3, 2010, e1000322, doi : 10.1371 / journal.pbio.1000322 .
  9. ^ A b Jaime E. Powell: The Late Cretaceous fauna of Los Alamitos, Patagonia, Argentina. Part 6: The titanosaurids. In: Revista del Museo Argentino de Ciencias Naturales Bernardino Rivadavia e Instituto Nacional de Investigación de las Ciencias Naturales. Paleontología. Vol. 3, No. 3, 1987, ISSN  0524-9511 , pp. 147-153.
  10. ↑ Jeffrey A. Wilson, Paul Upchurch: A Revision of Titanosaurus Lydekker (Dinosauria - Sauropoda), the first dinosaur genus with a 'gondwanan' distribution. In: Journal of Systematic Palaeontology. Vol. 1, No. 3, 2003, ISSN  1477-2019 , pp. 125-160, doi : 10.1017 / S1477201903001044 .
  11. ↑ Aldirene Costa Franco-Rosas, Leonardo Salgado, Claudio Fabián Rosas, Ismar de Souza Carvalho: Nuevos materiales de titanosaurios (Sauropoda) en el Cretacico Superior de Mato Grosso, Brazil. In: Revista Brasileira de Paleontologia. Vol. 7, No. 3, 2004, pp. 329–336, digital version (PDF; 2.29 MB) .
  12. ↑ a b c d Gabriel Casal, Rubén Martínez, Marcelo Luna, Juan C. Sciutto, Matthew Lamanna: Aeolosaurus colhuehuapensis sp. nov. (Sauropoda, Titanosauria) de la Formación Bajo Barreal, Cretácico superior de Argentina. In: Revista Brasileira de Paleontologia. Vol. 10, No. 1, 2007, pp. 53-62, digital version (PDF; 2.85 MB) .
  13. ^ Jorge Calvo , Juan Domingo Porfiri: Panamericansaurus schroederi gen. Nov. sp. nov. Un nuevo Sauropoda (Titanosauridae-Aeolosaurini) de la Provincia del Neuquén, Cretácico Superior de Patagonia, Argentina. In: Brazilian Geographical Journal. Vol. 1, No. 1, 2010, ISSN  2179-2321 , pp. 100-115, online .
  14. ↑ Ben Creisler: Dinosauria Translation and Pronunciation Guide. Archived from the original on July 15, 2010 ; accessed on August 27, 2014 .
  15. ↑ Thiago S. Marinho, Carlos Roberto A. Candeiro: Titanosaur (Dinosauria: Sauropoda) Osteoderms from the Maastrichtian of Uberaba, Minas Gerais State, Brazil. In: Gondwana Research . Vol. 8, No. 4, 2005, ISSN  1342-937X , pp. 473-477.

Web links

Commons : Aeolosaurus  - collection of images, videos and audio files