Austrocheirus
Carnivore·Late Cretaceous·Pari Aike Formation·Bipedal
Austrocheirus was a medium-sized theropod dinosaur that inhabited Earth during the Late Cretaceous period. Its scientific name, meaning "southern hand," reflects its discovery location and a notable anatomical feature. While initially classified within Abelisauroidea, its exact phylogenetic placement remains a subject of ongoing scientific discussion.
Key Facts
- ›Lived during the Late Cretaceous period.
- ›Named "southern hand" due to its origin and hand anatomy.
- ›Fossils found in the Pari Aike Formation.
- ›Estimated to be 5.5–6.5 meters (18–21 ft) long.
- ›Its classification within theropod groups is debated.
- ›Represents a potentially early MID-sized abelisauroid with unreduced forelimbs.
- Medium-Sized Theropod
- Estimated Length of 5.5–6.5 Meters
- Partial Manus Found
- Possessed A Tibia, Axial Bones, and A Foot Bone
Noasaurus, Berberosaurus, Ceratosaurus, Berthasaura, Afromimus
About Austrocheirus
Austrocheirus is an extinct genus of theropod dinosaur that roamed the Earth during the Late Cretaceous period. Named in 2010 by paleontologists Martin Ezcurra, Federico Agnolin, and Fernando Novas, its scientific name, Austrocheirus isasii, translates to "southern hand," honoring both its geographic origin and the discoverer of its remains, Marcelo Pablo Isasi.
Fossil Discoveries and Anatomy
The fossils attributed to Austrocheirus were unearthed on March 17, 2002, within the Pari Aike Formation. This geological layer dates back to the Campanian to Maastrichtian stages of the Late Cretaceous. The known fossil material includes a partial manus (hand), a tibia, axial bones, and a foot bone. These remains indicate that Austrocheirus was a medium-sized theropod, with estimates placing its length between 5.5 and 6.5 meters (18 to 21 feet).
Classification Debates
The phylogenetic placement of Austrocheirus has been a subject of scientific discussion. Initial cladistic analyses suggested a basal position within the Abelisauroidea clade, distinguishing it as one of the first known mid-sized abelisauroids that did not exhibit the severely reduced forelimbs characteristic of many other members of that group. However, this classification has been challenged, with some researchers arguing that the features used to justify its placement in Abelisauroidea are also present in non-abelisauroid theropods. Consequently, Austrocheirus has also been classified as a theropod dinosaur of uncertain phylogenetic placement, or more recently, within a clade named Berthasauridae, which nests outside of Noasauridae and as the sister taxon to abelisauroids.
Source: Wikipedia ↗
Frequently Asked Questions
When did Austrocheirus live?
Austrocheirus lived during the Late Cretaceous period. Fossils were discovered in the Pari Aike Formation, which dates from the Campanian to Maastrichtian stages of this period.
What does the name Austrocheirus mean?
The generic name "Austrocheirus" means "southern hand." This name reflects its discovery in the Southern Hemisphere and a characteristic feature of its hand.
How big was Austrocheirus?
Austrocheirus was a medium-sized theropod dinosaur. It is estimated to have measured between 5.5 to 6.5 meters (18 to 21 feet) in length.
Where were the fossils of Austrocheirus found?
The fossils of Austrocheirus were discovered in the Pari Aike Formation. This geological formation is located in a region that implies a southern discovery.
What is known about Austrocheirus's classification?
The classification of Austrocheirus has been debated. While some analyses suggest a basal position within Abelisauroidea, others place it as a theropod of uncertain phylogenetic placement, or within a clade called Berthasauridae.
Related Dinosaur species
Abelisaurus
Abelisaurus was a genus of predatory theropod dinosaur that lived in South America during the Late Cretaceous Period. Known primarily from a partial skull, it is estimated to have been a bipedal carnivore reaching around 7.4 meters in length.
Acheroraptor
Acheroraptor is an extinct genus of dromaeosaurid theropod dinosaur that lived in North America during the Late Cretaceous period. It is known from fossil remains discovered in the Hell Creek Formation of Montana, United States. Acheroraptor is notable for being one of the geologically youngest dromaeosaurids, existing just before the Cretaceous-Paleogene extinction event.
Achillobator
Achillobator was a large, heavily-built dromaeosaurid theropod dinosaur that inhabited Mongolia during the Late Cretaceous period. It is distinguished by its robust skeleton, deep maxilla, and primitive pelvis, contrasting with the generally lighter build of other dromaeosaurids. This predator likely hunted large prey using its enlarged sickle claw.