Nopcsaspondylus (meaning "Nopcsa's vertebra", in reference to the original describer) is a genus of rebbachisaurid sauropod dinosaur (a type of large, long-necked quadrupedal herbivorous dinosaur) from the Cenomanian-age (Upper Cretaceous) Candeleros Formation of Neuquén, Argentina. It is based on a now-lost back vertebra described by Nopcsa in 1902 but not named at the time. The specimen had a small vertebral body and large hollows, now known to be typical of rebbachisaurids.

Nopcsaspondylus
Temporal range: Cenomanian
~99–93 Ma
Holotype dorsal vertebra of Nopcsaspondylus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Superfamily: Diplodocoidea
Family: Rebbachisauridae
Genus: Nopcsaspondylus
Apesteguía, 2007
Species:
N. alarconensis
Binomial name
Nopcsaspondylus alarconensis
Apesteguía, 2007

History of research

edit

The only known specimen of Nopcsaspondylus is a fossilized dorsal vertebra collected in 1889 by Slovenian researcher Hugo Zapałowicz and transferred to the geological collection of the University of Vienna. The first person known to study the specimen, Hungarian paleontologist Franz Nopcsa von Felső-Szilvás, described it in a 1902 publication and recognized it as belonging to a sauropod dinosaur, assigning it to the genus Bothriospondylus. According to Nopcsa, the label on the fossil stated that it was collected on the left bank of the Limay River in Argentina, about 80 kilometers south of the confluence of the Limay and Neuquén rivers.[1] A year later, American paleontologist John Bell Hatcher claimed that this vertebra was indistinguishable from those of Haplocanthosaurus, a sauropod known from Colorado, and that while the Argentine vertebra does not undoubtedly represent the same genus as the Colorado material, the two are very similar in structure.[2] The vertebra would next be studied by German paleontologist Friedrich von Huene, who wrote a monograph published in 1929 in which he reassigns the material to the species Titanosaurus australis, and the locality from which it originates is named as Alarcón for the first time.[3]

The Nopcsaspondylus specimen would not be published on again until the release of The Dinosauria in 1990, in which the vertebra was deemed similar to those found in northern Africa of Rebbachisaurus garasbae, supposedly extending the range of the Rebbachisaurus genus into South America as well.[4] Five years afterwards, Argentine paleontologists Jorge O. Calvo and Leonardo Salgado described a new species which they named Rebbachisaurus tessonei (currently moved to the genus Limaysaurus), the specimens of which originate from the same locality (now named as Barda Alarcón) as the vertebra first described by Nopcsa 93 years prior. They therefore claimed that Nopcsa's specimen, at this point already considered lost, was a vertebra of R. tessonei.[5]

In 2007, Argentine paleontologist Sebastián Apesteguía became the first author to recognize that the vertebra described by Nopcsa represents a new genus and species, and thus named this species as Nopcsaspondylus alarconensis. The generic name combines the surname of the first researcher to study it with the Greek word σπονδυλος (spondylus, meaning "vertebra"), while the specific name refers to Barda Alarcón, the locality where the fossil was discovered.[6]

References

edit
  1. ^ Nopcsa, Franz (1902). "Notizen über Cretacischen Dinosaurier. Pt. 3. Wirbel eines südamerikanischen Sauropoden" (PDF). Akademie der Wissenschaften (in German). 3: 108–114.
  2. ^ Hatcher, J. B. (1903). "Osteology of Haplocanthosaurus, with description of a new species, and remarks on the probable habits of the Sauropoda and the age and origin of the Atlantosaurus beds". Memoirs of the Carnegie Museum. 2 (1): 1–75. doi:10.5962/p.234822. ISSN 0885-4645.
  3. ^ von Huene, Friedrich (1929). Los saurisquios y ornitisquios del cretáceo argentino (in Spanish). Coni. pp. 3–4.
  4. ^ Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (1990). "Sauropoda". The Dinosauria. University of California Press. p. 394. ISBN 978-0-520-06726-4.
  5. ^ Calvo, Jorge Orlando; Salgado, Leonardo (December 1995). "Rebbachisaurus tessonei sp. nov. A new sauropod from the Albian-Cenomanian of Argentina; new evidence on the origin of the Diplodocidae". Gaia. 11: 13–33.
  6. ^ Apesteguía, Sebastián (2007). "The sauropod diversity of the La Amarga Formation (Barremian), Neuquén (Argentina)". Gondwana Research. 12 (4): 533–546. Bibcode:2007GondR..12..533A. doi:10.1016/j.gr.2007.04.007.