Eoabelisaurus

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Eoabelisaurus
Temporal range: Middle Jurassic
MEF Eoabelisaurus.jpg
Eoabelisaurus holotype fossil, Museo Paleontológico Egidio Feruglio
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Abelisauridae
Genus: Eoabelisaurus
Pol & Rauhut, 2012
Species: E. mefi
Binomial name
Eoabelisaurus mefi
Pol & Rauhut, 2012

Eoabelisaurus is a genus of abelisaurid theropod dinosaur from the Middle Jurassic Period of what is now South America. It was a bipedal carnivore that was estimated to have reached 6–6.5 metres (19.7–21.3 ft) in length,[1] although more recent estimates have yielded a size of 5.8 metres (19 ft).[2]

Discovery[edit]

Restoration

In 2009, Argentinian paleontologist Diego Pol discovered the skeleton of a theropod near the village of Cerro Cóndor in Chubut Province. In 2012, based on these remains, the type species Eoabelisaurus mefi was named and described by Pol and his German colleague Oliver Walter Mischa Rauhut. The generic name combines a Greek ἠώς, (eos), "dawn", with the name Abelisaurus, in reference to the fact it represents an early relative of the latter. The specific name honours the MEF, the Museo Paleontológico "Egidio Feruglio", where Pol is active.[1]

The holotype specimen, MPEF PV 3990, was uncovered in a layer of the Cañadón Asfalto Formation, a lacustrine deposit dating from the Aalenian-Bajocian, roughly 170 million years old. It consists of a nearly complete skeleton with skull, of a subadult or adult individual.[1]

Phylogeny[edit]

Eoabelisaurus was assigned to the basalmost position in Abelisauridae by its describers. It would, then, be the oldest abelisaurid species known by forty million years. The describers indicated that in the cladistic analysis a difference of only a single trait would have resulted in a position lower in the evolutionary tree, basal in the Abelisauroidea. The following cladogram follows their analysis.[1]

Ceratosauria 

Berberosaurus



Deltadromeus





Spinostropheus




Limusaurus



Elaphrosaurus




 Neoceratosauria 
 Ceratosauridae 

Ceratosaurus



Genyodectes



 Abelisauroidea 
 Noasauridae 

Laevisuchus



Masiakasaurus



Noasaurus



Velocisaurus



 Abelisauridae 

Eoabelisaurus




Rugops




Abelisaurus


 Carnotaurinae 


Majungasaurus



Indosaurus



Rajasaurus



 Brachyrostra 


Ilokelesia



Ekrixinatosaurus



Skorpiovenator



 Carnotaurini 

Carnotaurus



Aucasaurus












See also[edit]

References[edit]

  1. ^ a b c d Diego Pol & Oliver W. M. Rauhut (2012). "A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs". Proceedings of the Royal Society B: Biological Sciences. 279 (1804): 3170–5. doi:10.1098/rspb.2012.0660. PMC 3385738Freely accessible. PMID 22628475. 
  2. ^ Grillo, O. N.; Delcourt, R. (2016). "Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king". Cretaceous Research. doi:10.1016/j.cretres.2016.09.001.