Antarctosaurus ‭(‬Southern lizard‭)‬

Short Info

Antarctosaurus ‭(‬Southern lizard‭)‬

Phonetic : An-tarc-toe-sore-us.

Named By : Friedrich von Huene‭ ‬-‭ ‬1929

Diet : Herbivore

Size : Estimated 18 meters long maybe larger

Type of Dinosaur : Sauropod

Type Species : A.‭ ‬wichmannianus‭ (‬type‭)

Found in : Argentina, Chile, Uruguay

When it Lived : Late Cretaceous, 84-65 million years ago

Antarctosaurus (/aen,ta:rktoU’so:r@s/; meaning “southern lizard”) is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. The Antarctosaurus species that is the type, Antarctosaurus wichmannianus, as well as a different kind, the Antarctosaurus giganteus were first described by the popular German paleontologist Friedrich von Huene in 1929. Three other Antarctosaurus species have also been described since then, however later research has concluded that they are as doubtful or unlikely to belong to the Genus.

Steveoc 86, CC BY-SA 4.0, via Wikimedia Commons

The species that is the type, A. wichmannianus, is a source of controversy because there is doubt as to whether the remains described belong to the same individual or the same genus. The other kind of species A. giganteus, has been regarded as doubtful, however the fragments represent some of the biggest dinosaurs that have been discovered.

The remains of the dinosaur first came up in a 1916 publication however they weren’t completely identified and named until 1929, a monograph by paleontologist Friedrich von Huene. Antarctosaurus is not a reference to Antarctica, the continental area of Antarctica as it was originally discovered in Argentina however, it has the same origin, derived which comes from Greek terms anti- anti-, meaning ‘opposite to the other’, arktos, meaning “north” and which means lizard.. The term is used to refer to the reptile’s nature and geographical position on an island in the south of the continent.

Antarctosaurus wichmannianus is the most common species in the genus of Antarctosaurus. It was named in 1929 in honor of the first person to discover their remains from 1912 by geoscientist Ricardo Wichmann. Von Huene used the name A. wichmannianus to describe an extensive collection of bones that are believed to originate out of the Anacleto Formation in Rio Negro Province of Argentina that is believed to be the earliest Campanian in the age of. Two additional limb bones discovered within the Chubut Province in 1924, were also identified as A. Wichmannianus from von Huene in 1929. The subsequent studies however have questioned their connection towards the species.

Von Huene also named a fragmentary second species of Antarctosaurus in the same 1929 monograph which he tentatively referred to as cf. Antarctosaurus giganteus due to its size. The fossils were discovered in the Neuquen Province of Argentina, from the Plottier Formation which dates to the Coniacian-Santonian stage in the Late Cretaceous Period. The Plottier, as Anacleto, which is Anacleto, which is the younger Anacleto is part of the Neuquen Group.

There are only a few known remains of this species, and it is considered to be a nomen dubium for some. Others consider A. giganteus as being a plausible species, though it could be part of an entirely new genus. The year 1969 was the first time Leigh Van Valen considered A. wichmannianus and A. giganteus as growth levels of the species. She favoured the term A. giganteus. This notion is not a good one since A. wichmannianus was named earlier in the same paper , and since it is derived through more sources, and so it must be given precedence ahead of A. giganteus. The two species also are not part of an identical geological structure, which implies that they do not belong to the same period of time.

It was in 1933 that Von Huene and Charles Matley identified a different species, Antarctosaurus septentrionalis which means “northern”. The remains were discovered within the Lameta Formation of Madhya Pradesh State in India. The species is able to preserve significant anatomical data, but it was classified as a genus in 1994. Jainosaurus.

Antarctosaurus jaxarticus of Kazakhstan is recognized by only one femur. It was identified in 1938 by Soviet paleontologist Anatoly Riabinin in 1938, and was the first sauropod species to be discovered in Kazakhstan. It was found at an area in the Kyzylkum Desert, but the exact location is not known. It could have been part of the Syuksyuk Formation (originally identified as Dabrazinskaya Svita) which is believed to date up to Santonian phase of Late Cretaceous. Some researchers have proposed it either as Titanosauridae incertae sedis, either as the name dubium, or as an unnamed nomen nudum.

In 1970, two broken bones from the limbs and a fragmentary vertebra were discovered within the Adamantina Formation (originally identified as the Bauru Formation as well as been described as being the Sao Jose do Rio Preto Formation) located in northwestern Parana Basin in Brazil. The bones were first described by their researchers Fahad Moyses Arid as well as Luiz Dino Vizotto in the year 1971 in 1971 as A. brasiliensis. Other researchers have viewed this species as a nomen dubium or an undetermined titanosaur.

Antarctosaurus is a genus that has been criticized since none of the species listed have been identified from complete remains and the type species is comprised of elements of uncertain relationship, which has led to confusion in the taxonomy. Four additional species assigned to Antarctosaurus throughout the years Three have been deemed doubtful as well “Antarctosaurus” septentrionalis, was assigned its own genus, Jainosaurus.

The remains identified belong to sauropods, likely titanosaurs, an assemblage of large-bodied herbivores that are quadrupedal, typically having a an extended neck and tail. They also have a the head being small.

Source: Wikipedia