Pronunciation: KOH-muh-hoo-SOR-us
Meaning: Comahue lizard
Author/s: Carballido et al. (2012)
Synonyms: Limaysaurus sp. (Salgado, 2004)
First Discovery: Neuquén, Argentina
Discovery Chart Position: #794
Comahuesaurus windhauseni
Comahuesaurus was provisionally identified as a new species of the rebbachisaurid Limaysaurus by Salgado in 2004, based on three matching characters found in 126 fossils from at least three individuals (based on right thigh count) at a single dig site in Comahue called Puesto Díaz Quarry: (1) its vertebrae have a deeper hollow on the rear than on the front, (2) its forward-pointing hip bone (pubis) flares out at both ends and looks like a bow tie, and (3) its backwards-pointing hip bone (ischium) is curved.
Ironically, its curved ischium is the deal breaker, as a closer inspection by Carballido in 2012 revealed that it was actually straight, as in most other sauropods. Also, the 90° angle between the ischium and the point where thigh meets hip socket (acetabulum) is much sharper than the obtuse angle found in Limaysaurusas and most closely matches that of Zapalasaurus. The latter is reputed to be the basalmost member of Rebbachisauridae, so it and Comahuesaurus may form their own, as yet unnamed, group of primitive rebbachisaurids far removed from Limaysaurus and its limaysaurine clan.
In 2015, Garrido and Salgado presented a study of the Puesto Díaz Quarry in which they tried to work out why several individuals had died in the same area and concluded that such an accumulation was caused by a catastrophic event, in this case, a flood, judging by the lay of the bones. Coincidently, Comahue, meaning "place of abundance" in Mapuche, can also translate as "where the water hurt", which it certainly did. But all things considered, the fossils weren't in bad shape, so they must have been carried only a short distance before being buried. However, some bones seem randomly scattered and were perhaps exposed long enough to allow disarticulation by scavengers and decay.
Ironically, its curved ischium is the deal breaker, as a closer inspection by Carballido in 2012 revealed that it was actually straight, as in most other sauropods. Also, the 90° angle between the ischium and the point where thigh meets hip socket (acetabulum) is much sharper than the obtuse angle found in Limaysaurusas and most closely matches that of Zapalasaurus. The latter is reputed to be the basalmost member of Rebbachisauridae, so it and Comahuesaurus may form their own, as yet unnamed, group of primitive rebbachisaurids far removed from Limaysaurus and its limaysaurine clan.
In 2015, Garrido and Salgado presented a study of the Puesto Díaz Quarry in which they tried to work out why several individuals had died in the same area and concluded that such an accumulation was caused by a catastrophic event, in this case, a flood, judging by the lay of the bones. Coincidently, Comahue, meaning "place of abundance" in Mapuche, can also translate as "where the water hurt", which it certainly did. But all things considered, the fossils weren't in bad shape, so they must have been carried only a short distance before being buried. However, some bones seem randomly scattered and were perhaps exposed long enough to allow disarticulation by scavengers and decay.
(Anselmo Windhausen's Comahue Lizard)Etymology
Comahuesaurus is derived from the Mapuche "Comahue" (place of abundance), for the Comahue region where its remains were discovered, and the Greek "sauros" (lizard).
The species epithet, windhauseni, honors Anselmo Windhausen for his contribution to the geological knowledge of the Neuquén basin.
Discovery
The first remains of Comahuesaurus were discovered at Puesto Díaz Quarry in the Puesto Quiroga Member of the Lohan Cura Formation, on the northern slope of Cerro Aguada del León, 48 km east of Catan Lil town, La Picasa area, Neuquén province, Comahue region, Argentina, by Argentine palaeontologist José Fernando Bonaparte, between 1995 and 1996.
The holotype (MOZ-PV 6722) is the arch from a back vertebra.
Referred material from the same quarry includes 126 fossils from at least three individuals based on the presence of three right thigh bones.
