| Elaltitan | |
|---|---|
 | |
| Skeletal restoration, known material in blue | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Macronaria |
| Clade: | †Titanosauria |
| Clade: | †Lithostrotia |
| Genus: | †Elaltitan Mannion & Otero,2012 |
| Type species | |
| †Elaltitan lilloi Mannion & Otero, 2012 | |
Elaltitan is anextinctgenus of largelithostrotiantitanosaursauropoddinosaur known from theLate Cretaceous (midCenomanian toTuronian stage) ofChubut Province, southernArgentina. It contains a single species,Elaltitan lilloi.[1]
Elaltitan was first described and named by Philip D. Mannion and Alejandro Otero in2012 and thetype species isElaltitan lilloi. Thegeneric name is derived fromElal (pronounced as "ee-lal") - the god of theTehuelche people ofChubut Province andtitan, giant inGreek mythology. Thespecific name,lilloi, honors Miguel Lillo, for his contribution and legacy to natural sciences in Tucumán.[1]
Elaltitan is known only from a single individual, represented by an associated partialpostcranialskeleton. Theholotype includes both PVL 4628 and MACN-CH 217 comprising threedorsal vertebrae, twocaudal vertebrae, leftscapula, lefthumerus, leftradius, bothulnae, rightpubis, proximal half of rightfemur, distal part of lefttibia, distal two-thirds of leftfibula, rightastragalus andcalcaneum.Elaltitan is the first titanosaur skeleton to preserve an associated calcaneum. Although all of the material was originally housed in the Colección de Paleontología de Vertebrados de la Fundación Instituto Miguel Lillo in Tucumán, Argentina and accessioned as PVL 4628, the dorsal vertebrae and complete caudal vertebra were subsequently moved to the Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" in Buenos Aires, where they were accessioned as MACN-CH 217. The holotype specimen was collected by an expedition of theFundación Miguel Lillo and theUniversidad Nacional de Tucumán, led byJosé Fernando Bonaparte, from the right (southern) bank of theSenguerr River, in the area between the bend of this river and the Pampa de María Santísima, southeast of the southernmost part of the Sierra de San Bernardo,Chubut Province. It came from the lower member of theBajo Barreal Formation, dating to the middleCenomanian to theTuronian stage of theLate Cretaceousperiod, about 96.5-89.3 million years ago.[1]
Theholotype ofElaltitan was originally attributed toAntarctosaurus sp. by Bonaparte & Gasparini (1979), and later tentatively referred toArgyrosaurus by Jaime Powell (1986, 2003). Philip D. Mannion and Alejandro Otero (2012), who named the genus, diagnosedElaltitan by a unique combination of characters, as well as oneautapomorphy. The autapomorphy (unique trait) is the presence of dorsoventrally tallneural arch restricted to anterior half of centrum (excluding condylar ball) in anterior-mostcaudal vertebrae. Other unusual characters include a spinopostzygapophyseal laminae in middle–posterior dorsal vertebrae bifurcate into medial and lateral branches, an astragalar ascending process that does not extend to the posterior margin of the astragalus and the presence of a calcaneum. Other potentially unusual features were also listed. These traits distinguishElaltitan from all othertitanosauriforms, includingAntarctosaurus andArgyrosaurus, as well as other sauropods from the lower member of the Bajo Barreal Formation, such asDrusilasaura andEpachthosaurus. Based on comparisons with the morphologically similarfemur of "Antarctosaurus" giganteus, which was measured as 231 cm (91 in) in length, the complete femur ofElaltitan would be approximately the same size. This makes it one of the largest knownsauropods ever to have existed. Mannion & Otero (2012) also pointed out that there are currently 39 Cretaceous South American titanosauriform genera considered to be valid, the majority of which (31) are from Argentina.[1] Its weight has been estimated at 42.8 tonnes (42.1 long tons; 47.2 short tons) in 2014,[2] and at 35.4 tonnes (34.8 long tons; 39.0 short tons) in 2018.[3] However, in 2020 Molina-Perez and Larramendi gave a smaller size of 20 meters (66 ft) and 23 tonnes (25.35 short tons).[4]
