Aeolosaurus
- Aeolosaurus rionegrinus (type )
- Aeolosaurus colhuehuapensis ( Casal et al., 2007)
- Aeolosaurus maximus ( Santucci et al., 2011)
Aeolosaurus is a genus of sauropod dinosaur from the group of Titanosauria who lived in the Upper Cretaceous of South America. The fossils come from different localities in Argentina and Brazil and can be dated to the late Campanian and Maastrichtian early.
So far, three types have been described: the type species Aeolosaurus rionegrinus the kind described in 2007 Aeolosaurus colhuehuapensis and the type first described in 2011 Aeolosaurus maximus. Sometimes Aeolosaurus is summarized together with Gondwana titanium in the group Aeolosaurini.
Features
Aeolosaurus was like all sauropods an herbivore with a long neck and tail and reached an estimated length of about 15 meters. Like some other Titanosaurier had Aeolosaurus osteoderms ( dermal bones plates). Two osteoderms were discovered in connection with Aeolosaurus remnants in the Allen lineup - the better preserved of these two findings is oval and measures 15 inches in diameter. Two other osteoderms come from a quarry of Marília Formation, which hid the bones of Aeolosaurus, and therefore may also be assigned to this genus. During one of these osteoderms is oval, the other shows a D shape and runs upward to a point. Osteoderms of titanosaurs are always only found in a few copies. This could indicate that Titanosaurier contributed only a few osteoderms and that the latter thus - unlike previously thought - not the defense against predators served.
This genus can be loud Upchurch and colleagues ( 2004) by the following features of other genres define ( autapomorphies ): Thus, the upper (dorsal ) anterior edge of the spinous processes of the middle caudal vertebrae is extended to the front, thus forming an overhang over the front area of the vertebral body. Furthermore, the upper arm bone (humerus ) shows a distinct knob -like projection on Deltopectoralkamm. The anterior articular processes ( prezygapophyses ) of the caudal vertebrae were long and showed very wide connection surfaces.
System
The systematic position within the Titanosauria is controversial. Initially, the genus has been classified as a relative of Titanosaurus within the Titanosaurinae - this name is, however, currently considered by many researchers as invalid. Upchurch and colleagues ( 2004) classify Aeolosaurus within the Lithostrotia that includes all advanced Titanosaurier up on some of the original species.
Some researchers Aeolosaurus and the closely related Gondwana titanium are summarized in a separate group - the Aeolosaurini. The genera Rinconsaurus, Panamericansaurus and Maxakalisaurus are sometimes also classified within the Aeolosaurini. Santucci and colleagues ( 2011) come to the conclusion that Panamericansaurus, Maxakalisaurus and Rinconsaurus more primitive representatives of Aeolosaurini were as Aeolosaurus and Gondwana titanium. The Aeolosaurini can be distinguished from other titanosaurs, among others, by the vertebral arches of the middle caudal vertebrae that extend beyond the front edge of the vertebral bodies addition to the front.
Discovery history, types and naming
This genus was described in 1987 by Jaime Powell for the first time scientifically. Powell's description is based on fragmentary remains from the Angostura Colorada Formation of the Argentine province of Río Negro - seven cervical vertebrae, both shoulder blades partially preserved, two upper arm bones, five metacarpal bones, the right shin (tibia) and fibula ( fibula ) as well as an ankle bone ( astragalus ). The genus name Aeolosaurus ( " Aeolus ' lizard" ) has the god of the winds of the Roman and Greek mythology, Aeolus ( Aeolus Latinized ), which is an allusion to the strong winds in the Patagonia region. The specific epithet rionegrinus points to the locality.
In the aftermath Aeolosaurus other findings were attributed. So arranged Salgado and Coria this genus fossils from the lower layer member of the Allen lineup to (1993 ), the Argentine paleontologists discovered close in June 1989 in Salitral Moreno reference in General Roca in Río Negro. The fossils come from several individual finds and close five caudal vertebrae, ulna, radius (radius ), a metacarpal bone, pubis ( pubic ), ischial ( ischium ) and two osteoderms ( dermal bones plates) with a. Salgado and Coria suggest that these findings might belong to another type of Aeolosaurus because distinguish the vertebrae of the tail shorter and more robust prezygapophyses and by otherwise positioned postzygapophyses of the type species Aeolosaurus rionegrinus. However, you could give up due to the incomplete fossil record to the designation of a new species and described the findings as Aeolosaurus sp.
A partial skeleton from the Los Alamitos Formation, also of Río Negro, was described by Salgado and colleagues ( 1997) and consists of four caudal vertebrae, two thoracic legs ( sternum), a left humerus, two metacarpal bones, a partial left femur, a left tibia, a fibula, a talus and four metatarsal bones; Furthermore, it was discovered a series of 15 caudal vertebrae.
In the years 2000, 2001 and 2002 fossils were attributed from the Marília Formation from near Uberaba in Brazil, the genus Aeolosaurus. In the same quarry that held the bones, osteoderms were found which resemble the two already known Aeolosaurus osteoderms and thus also could include Aeolosaurus. More 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. Since these bones were found in an area of only ten square meters, they could have belonged to one and the same individual.
2007, a series of 21 caudal vertebrae, which is still in the anatomical composite, described as new Aeolosaurus Style - Aeolosaurus colhuehuapensis. These vortices series comes from a currently rising out of the water island in Colhué Huapi, one of the largest lakes of Argentina, in the province of Chubut. The site belongs to the Bajo- Barreal lineup. These vertebrae differ from the type species Aeolosaurus rionegrinus including through deep pits ( fossa ) between the Transversprozessen and at the base of the spinous processes. The Artepitheth colhuehuapensis has the lake Colhué Huapi in Chubut, where the fossils were found.
2011 Rodrigo M. Santucci and colleagues described a third type, Aeolosaurus maximus. This type is based on a fragmentary skeleton, which was salvaged in 1997 and 1998 by paleontologists of the Museu de Paleontologia de Monte Alto from the layers of Adamantina formation in the Brazilian state of São Paulo. This skeleton consists of cervical vertebrae, caudal vertebrae, ribs and leg bone, the humerus, femur, vertebrae and anterior caudal vertebrae were found in their original anatomical position.