| Laplatasaurus | |
|---|---|
 | |
| Tibia & fibula ofLaplatasaurus. Scale bar equals 10cm. | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Macronaria |
| Clade: | †Titanosauria |
| Genus: | †Laplatasaurus von Huene, 1929 |
| Type species | |
| †Laplatasaurus araukanicus von Huene, 1929 | |
| Synonyms | |
| |
Laplatasaurus (meaning "La Plata lizard", named forLa Plata,Argentina) is agenus oftitanosauriansauropoddinosaur that lived during theLate Cretaceous inSouth America, with the holotype and only known specimen found in theAnacleto Formation.
The genus was named in 1927 byFriedrich von Huene, but without a description, so that it remained anomen nudum.[1] In 1929 thetype species,Laplatasaurus araukanicus, was described by Huene.[2] The generic name refers to La Plata. Thespecific name is derived from theAraucanos orMapuche. By accident Huene in 1929 also mentioned a "Laplatasaurus wichmannianus" but that was alapsus calami forAntarctosaurus wichmannianus. In 1933 however, he andCharles Alfred Matley renamedTitanosaurus madagascariensis toLaplatasaurus madagascariensis.[3] This last species is today commonly referred to the originalTitanosaurus.
Huene basedLaplatasaurus on fragmentary material found in three locations inArgentina, in strata of theAnacleto Formation,[4] dating from theCampanianfaunal stage. It consisted of limb elements, some dorsal vertebrae and a series of caudal vertebrae. Part of the finds had earlier been referred byRichard Lydekker toTitanosaurus australis. Huene never assigned aholotype, but in 1979José Fernando Bonaparte choseMLP 26-306 as thelectotype, a specimen consisting of atibia and afibula that perhaps originate from different individuals.
Huene assigned those fossils toLaplatasaurus that seemed to indicate a rather large yet at the same time elegantly built sauropod. The about eighteen metres (59 ft) longLaplatasaurus was perhaps similar toSaltasaurus.Osteoderms forming an armored plating on the back, have been referred toLaplatasaurus but the association is uncertain. These plates had much smaller ridges than those ofSaltasaurus.
AMegaloolithusegg found in theAnacleto Formation inAuca Mahuevo,Argentina[5] that was once assigned toTitanosaurus may have instead been laid byLaplatasaurus.
Huene placedLaplatasaurus in theTitanosauridae, which is still a common classification. In his 2003 review of South American titanosaurs,Jaime Eduardo Powell assignedLaplatasaurus toTitanosaurus, creating the new combinationTitanosaurus aurakanicus.[6] Others however, continued to treatLaplatasaurus as valid genus separate fromTitanosaurus.[7][8][9]
A 2015 re-assessment ofLaplatasaurus found it to be closely related toBonitasaura,Futalognkosaurus,Mendozasaurus, andUberabatitan. The genus was restricted to the lectotype, and the material from Rancho de Avila was assigned to cf.Bonitasaura sp.[4]
