Nowy dinozaur z wczesnej kredy
: 9 września 2006, o 11:38
Smith, J., Tshakreen, S., Rasmussen, S. & Lamanna, M. (2006) - Nowy dinozaur z wczesnej kredy z Libii.
DD.org - abstrakt pisze:Although the interval has been rather well sampled, a solid understanding of the nature of the Cretaceous tetrapod faunas of mainland Africa remains elusive. This is particularly true of Libya, which has produced only a few fragmentary Cretaceous tetrapod remains. For example, the previous record of Dinosauria from the country is limited to a few isolated bones and teeth from the ?Early Cretaceous (provenance is unclear for some of the remains) of the Jabal Nafusah area (between Tunisia and Tripoli) and several bones from the Late Cretaceous (probably Cenomanian, ~99-93 Ma) of the Ghadames and Draa Ubari regions.
In August 2005, as an expansion of ongoing research in the Late Cretaceous of Egypt, we conducted what appears to have been the first joint Libyan-American dinosaur expedition. Over three weeks we traveled ~4000 km in northeaster and south-central Libya, penetrating to ~450km north of the Chad border. Along Jabal Nafusah we produced fossil vertebrates from 13 localities in the Aptian-Albian (~125-99 Ma) Chicla Formation and the underlying uppermost Cabao Formation (uppermost strata regarded as upper Neocomian, ~125 Ma).
The assemblage from these sites consists largely of shark, turtle, lungfish, and crocodyliform (?two species, including bones and teeth of a very large form) remains, and numerous unidentified tetrapod elements. Dinosaurs are currently represented by fragmentary remains of a ?titanosauriform sauropod and the partial skeleton of a theropod.
The theropod, the most complete record of a Libyan dinosaur to date, was found at the top of the Cabao Formation near the town of Nalut, ~40 km east of the Tunisian border. It consists of vertebrae and appendicular elements. This specimen, which appears to be a previously unrecorded taxon as evidenced by several autapomorphies, possesses femoral and tibial characters very similar to Masiakasaurus and is thus perhaps a large-bodied noasaurid. If correctly identified, this find extends the African record of Abelisauroidea into the Neocomian.