Dinheirosaurus is a genus of diplodocid sauropod dinosaur that is known from fossils uncovered in modern-day Portugal. It may represent a species of Supersaurus.[1] The only species is Dinheirosaurus lourinhanensis, first described by José Bonaparte and Octávio Mateus in 1999 for vertebrae and some other material from the Lourinhã Formation. Although the precise age of the formation is not known, it can be dated around the early Tithonian of the Late Jurassic.
The known material includes two cervical vertebrae, nine dorsal vertebrae, a few ribs, a fragment of a pubis, and many gastroliths. Of the material, only the vertebrae are diagnostic, with the ribs and pubis being too fragmentary or general to distinguish Dinheirosaurus. This material was first described as in the genus Lourinhasaurus, but differences were noticed and in 1999 Bonaparte and Mateus redescribed the material under the new binomial Dinheirosaurus lourinhanensis. Another specimen, ML 418, thought to be Dinheirosaurus, is now known to be from another Portuguese diplodocid. This means that Dinheirosaurus lived alongside many theropods, sauropods, thyreophorans and ornithopods, as well as at least one other diplodocid.
Dinheirosaurus is a diplodocid, a relative of Apatosaurus, Diplodocus, Barosaurus, Supersaurus, and Tornieria. Among those, the closest relative to Dinheirosaurus is Supersaurus.
ML 414 was first uncovered in 1987 by Mr. Carlos Anunciação. He was associated with the Museu da Lourinhã, and after the excavations which lasted from the time of discovery until 1992,[2] the specimen was then moved into the museum, and catalogued under the number 414.[3] Dantas et al. preliminarily announced ML 414 as soon as the excavations were complete. To remove the fossils from the surrounding rock, a bulldozer and tilt hammer were needed. The fossils were situated at the top of a coastal cliff, and once removed, were shipped to Lourinhã in two blocks with the help of a crane. A year before being described as a new taxon, Dantas et al. assigned ML 414 to Lourinhasaurus alenquerensis, previously grouped under Apatosaurus. José Bonaparte and Octávio Mateus studied the material of Lourinhasaurus, concluding one specimen, under the name ML 414, to be more closely related to diplodocids of the Morrison Formation, and thus warranting a new binomial name. This new species was described as Dinheirosaurus lourinhanensis, with a full meaning of "Porto Dinheiro lizard from Lourinhã".[2][3]
Dinheirosaurus material included vertebrae, ribs, partial pelvis, and gastroliths. The vertebrae were certainly from the cervical and dorsal regions, and are articulated. The two cervicals are not greatly preserved, although the twelve dorsals are articulated and in good condition. Other vertebral material includes seven centra that are fragmentary and a few neural arches, which are unattached. 12 dorsal ribs are preserved, as well as some appendicular elements.[2] David Weishampel et al. did not recognize all the material as belonging to Dinheirosaurus, and only found 9 dorsals in the holotype, while also misinterpreting the pubis as a limb fragment. They also incorrectly stated that it was found in the Camadas de Alcobaça Formation.[4] Another pair of vertebrae, under collection number ML 418, was originally assigned to Dinheirosaurus by Bonaparte and Mateus, but is now considered to be a distinct new unnamed genus of diplodocid.[3][5]
Dinheirosaurus was an average sized diplodocid, and had an elongated neck and tail.[4] The main features of the genus are based on its vertebral anatomy, and multiple vertebrae from across the spine have been found.[2] In total, Dinheirosaurus would have had an approximate length of 20–25 metres (66–82 ft) and weighed 8.8 metric tons (9.7 short tons).[6][7][8]