Berberosaurus
| Berberosaurus | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| Lower Jurassic ( Pliensbachian to Toarcian ) | ||||||||||||
| 190.8 to 174.1 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Berberosaurus | ||||||||||||
| Allain et al. , 2007 | ||||||||||||
| Art | ||||||||||||
|
Berberosaurus is a genus of theropod dinosaur and the oldest known representative of the Ceratosauria . So far only a very fragmentary, skullless skeleton is known, which comes from the Lower Jurassic ( Pliensbachian to Toarcian ) Morocco .
The genus was scientifically described in 2007 with the only species, Berberosaurus liassicus . Berberosaurus is particularly important scientifically because it is one of the few dinosaurs from the late Lower Jurassic. The continental faunas are very sparsely known from this time. As the oldest known ceratosauria, this genus also closes an important gap in the fossil record, as the next oldest ceratosauria only appear in the Upper Jurassic ( Kimmeridgian to Tithonian ).
The name Berberosaurus ("Berber lizard") refers to the Berbers who live in western North Africa. The second part of the species name, liassicus , refers to the lias , an outdated name for the Lower Jurassic period.
features
At an estimated 6.2 meters in length, Berberosaurus was a medium-sized theropod that reached a size similar to its related Elaphrosaurus . This genus can be distinguished from other Ceratosauria by a unique combination of characteristics: For example, the cervical vertebrae were short and strongly pneumatized (with air-filled chambers), while the shinbone (tibia) appears triangular when viewed from below.
Systematics
The systematic position within the Ceratosauria is controversial: Allain and colleagues (2007) consider Berberosaurus as the most original and oldest known representative of the Abelisauroidea , a group that includes all derived (advanced) representatives of the Ceratosauria. Berberosaurus would be more original than Xenotarsosaurus , the Abelisauridae and Noasauridae , but more derived than, for example, Spinostropheus , Elaphrosaurus and Ceratosaurus . These authors classify the Triassic Coelophysoidea as a subgroup of the Ceratosauria, whereby Berberosaurus would not be the oldest Ceratosauria, but only the oldest Abelisauroidea. Today, however, most studies classify the Coelophysoidea outside of the Ceratosauria. The assignment to the Abelis auroid is based on three features that can be found on the vertebral arches of the cervical vertebrae.
Carrano and Sampson (2008), on the other hand, classify Berberosaurus as standing outside of the Abelisauroidea. The authors note that this genus shows a number of features that are otherwise only known from basal ceratosauria, such as the shape of the muscle attachment points (trochanter) of the thighbone (femur). A cladistic analysis comes to the preliminary conclusion that Berberosaurus is more basal than Ceratosaurus .
Find
The only known skeleton was found near the village of Toundoute in the High Atlas in the Moroccan province of Ouarzazate . The fossils were found on an area of 4 m²; The holotype specimen of the early sauropod Tazoudasaurus was discovered 100 m from this site . The fragmentary remains of berberosaurus include a cervical vertebra, the front part of the sacrum, the second left metacarpal bones, the right femur, two fragments of the tibia, and a left fibula (fibula) tools. The skeleton is kept in the collection of the Muséum d'Histoire Naturelle de Marrakech .
Individual evidence
- ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 78, online ( memento of the original of July 13, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. .
- ^ A b c Matthew T. Carrano, Scott D. Sampson: The Phylogeny of Ceratosauria (Dinosauria: Theropoda). In: Journal of Systematic Palaeontology. Vol. 6, No. 2, 2008, ISSN 1477-2019 , pp. 183-236, doi : 10.1017 / S1477201907002246 .
- ↑ a b c d e Ronan Allain, Ronald Tykoski, Najat Aquesbi, Nour-Eddine Jalil, Michel Monbaron, Dale Russell , Philippe Taquet : A basal abelisauroid from the late Early Jurassic of the High Atlas Mountains, Morocco, and the radiation of ceratosaurs . In: Journal of Vertebrate Paleontology. Vol. 27, No. 3, 2007, ISSN 0272-4634 , pp. 610-624, doi : 10.1671 / 0272-4634 (2007) 27 [610: AADTFT] 2.0.CO; 2 .
- ↑ Thomas R. Holtz Jr .: Supplementary Information. to: Thomas R. Holtz Jr .: Dinosaurs. The most complete, up-to-date Encyclopedia for Dinosaur Lovers of all ages. Random House, New York NY 2007, ISBN 978-0-375-82419-7 , online (PDF; 184.08 kB) .
