Aucasaurus ‭(‬Auca lizard‭)‬

Short Info

Aucasaurus ‭(‬Auca lizard‭)‬

Phonetic : Aw-cah-sore-us.

Named By : Coria,‭ ‬Chiappe‭ & ‬Dingus‭ ‬-‭ ‬2002

Diet : Carnivore

Size : Estimated 5 meters long

Type of Dinosaur : Large Theropod

Type Species : A.‭ ‬garridoi‭ (‬type‭)‬

Found in : Argentina‭ ‬-‭ ‬Anacleto Formation

When it Lived : Late Cretaceous, 84-71 million years ago

Aucasaurus is a genus that includes medium-sized abelisaurid dinosaurs from Argentina which lived during the Late Cretaceous (Santonian to Campanian stage) of the Anacleto Formation. This was larger than Carnotaurus but was more descended in certain ways, like its extremely shortened arms and a complete lack of fingers. The type skeleton is fully complete up to the 13th caudal vertebra and is fairly well-studied, and is the largest known abelisaurid. However, the skull is damaged, causing some paleontologists[who?] to think that it was in a fight prior the time of death.


Aucasaurus
Kabacchi, CC BY 2.0, via Wikimedia Commons


As of 2009 Novas proposed that Aucasaurus garridoi could represent a synonym junior for Abelisaurus comahuensis. In 2010, Gregory S. Paul renamed Aucasaurus garridoi into Abelisaurus garridoi. The change was not accepted.

Aucasaurus is recognized from discoveries from Aucasaurus was discovered in Rio Colorado Subgroup, a Late Cretaceous group comprising the Anacleto Formation in the Neuquen Basin in Argentina that has produced numerous dinosaur fossils. Numerous sauropod eggs have also been found in this deposit.

Aucasaurus skull, which was short and deep-snouted was not as long or as deep-snouted of Carnotaurus. Additionally there were no horns instead, Aucasaurus had two lower ridges over each eye.

In 2010 Gregory S. Paul estimated the length of its body at 5.5 metresand its weight as 700 kilograms. In 2016 the length of its body was estimated at 6.1 meters (20 feet) and at the very least 1.5 tonnes in mass (comparable with Skorpiovenator) but it was more heavy than the Ilokelesia genus that was believed to weigh between 200 and 240 kilograms in weight. In a thorough analysis of the size of an abelisaur.

The arms that were small of Aucasaurus were similar to those of its horned kin but were proportionally bigger because of its smaller size. The bones did not have the boney processes as well as some of the unique proportions that were found in Carnotaurus. Its hand Aucasaurus was unique: Four metacarpals were found however those in the fourth and first had no fingers. The third and the second had fingers, however they were very small and did not have claws.

A study was conducted using the braincase of Aucasaurus in the year 2015 by Ariana Paulina-Carabajal as well as Cecilia Succar, in which the skull’s material was scanned with an Medical CT machine. Virtual three-dimensional inner ear as well as endocasts of the cranial region were taken and visualized with imagine software from the University of Alberta. A latex cranial endocast of the ear was as well. The forebrain, the midbrain and hindbrain have the same structure of those amphibians Majungasaurus as well as Indosaurus. But, Aucasaurus exhibits a floccular process that is comparatively bigger than Majungasaurus. It is also the only animal to have a floccular process. Aucasaurus this flocculus contained within an 8-shaped recess with a similar dimensions and shape to the one seen in Abelisaurus and Abelisaurus, suggesting that both Patagonian taxa had an a bit wider variety of movements for the head. The labyrinth in an inner ear identical in size and shape with the semicircular canals found in Majungasaurus, but the semicircular canal to the left is smaller in Aucasaurus.

Source: Wikipedia