Berberosaurus

• Morocco ( Toundoute - continental series)

• Berberosaurus liassicus

Berberosaurus is a genus of theropod dinosaur and oldest known representatives of Ceratosauria. So far, a very fragmentary skull -less skeleton is only known that dates back to the Early Jurassic ( Pliensbachian to Toarcian ) of Morocco.

The genus was described scientifically with the only kind, Berberosaurus liassicus 2007. Berberosaurus is scientifically particularly significant because it is one of the few dating from the late Jurassic dinosaurs. From this time the continental faunas are preserved only very sparse. As the oldest known Ceratosauria this genus also fills an important gap in the fossil record because the next oldest Ceratosauria appear only in the Upper Jurassic ( Kimmeridgian to Tithonian ).

The name Berberosaurus ( " Berber lizard" ) has the Berbers who live in the western North Africa. The second part of the species name, liassicus, has the Lias, an obsolete term for the epoch of the Lower Jurassic.

Features

Berberosaurus was having a length of approximately 6.2 meters, a medium-sized theropod, which reached a similar size as the related Elaphrosaurus. From other Ceratosauria can distinguish this genus by a unique combination of features: For example, the cervical vertebrae were short and highly pneumatized ( permeated with air-filled chambers ), while the shinbone ( tibia) viewed from below appears triangular.

System

The systematic position within the Ceratosauria is controversial: Allain and colleagues ( 2007) consider Berberosaurus as original and oldest known representatives of Abelisauroidea, a group that summarizes all derived ( advanced ) Representatives of Ceratosauria. This Berberosaurus would indeed be more original than Xenotarsosaurus that Abelisauridae and Noasauridae, but derived as for example Spinostropheus, Elaphrosaurus and Ceratosaurus. These authors classify the Triassic Coelophysoidea as a subgroup of Ceratosauria, which Berberosaurus not the oldest Ceratosauria, but only the oldest Abelisauroidea would. Today the Coelophysoidea however classified by most studies outside the Ceratosauria. The assignment to the Abelisauroidea based on three features that can be found on the vertebral arches of the cervical vertebrae.

Carrano and Sampson (2008) classify Berberosaurus opposite to this as outside the Abelisauroidea. The authors conclude that this genus shows a number of features that are otherwise only known from basal Ceratosauria, such as the shape of the muscle attachment sites ( trochanter ) of the femur (femur). A cladistic analysis comes to the preliminary conclusion that Berberosaurus is basal as Ceratosaurus.

Discovery

The only known skeleton was recovered near the village Toundoute in the High Atlas of Morocco Ouarzazate province. The fossils were found in an area of ​​4 m²; The holotype specimen of early sauropod Tazoudasaurus was 100 meters away from this locality discovered. The fragmentary remains of Berberosaurus include a neck vertebra, the anterior part of the sacrum, the second left metacarpal bone, right femur, two fragments of the tibia, as well as a left fibula ( fibula ) with a. The skeleton is preserved in the collection of the Muséum d' Histoire Naturelle de Marrakech.