The NEW Middle Cretaceous Fossil Fauna from Ramlia Taouz, South East Morocco
Name: Rhyncodercetis sp. / Rhynchodercetis Gar Fish(Needle fish);
Chordata Morocco, Middle East, Lebanon, Europe. Middle-Upper Cretaceous. Upper (95 M.Y.O.) Agoult/Daoura/Gara Sbaa, SW Morocco.
Phylum:
Class: Osteichthyes
Subclass: Neopterygii
Subdivision: Teleostei
Order: Auolpiformes
Suborder: Ichthyotrngoidei
Family: Darcetidae.
Geografical distribution:
Geological range:
Age:
Fossil Site:
This new species and maybe new genus of fossil fishes from Morocco belongs to the order of Aulopiformes, an Order of uncommon and basal Neopterygian fishes, that reached its apogee during the Cretaceous period.
This new species and maybe new genus of Darcetidae from Morocco is usually rapresented by not very large fish, with slender and almost arrow-shaped bodies. Head is extremely elongate up to 1/3 of the whole lenght of the animal and shallow. Upper and lower jaws are lenghtened to form a rostrum, with upper jaw projecting only slightly beyond the lower. Dorsal fin in the anterior half of the body, opposite the small pelvic fins. Anal fin likewise small. Caudal fin forked, with relatively narrow lobes.
Small predators with no recent relatives
This form from Upper Cretaceous from Morocco is most probably closely related to similar forms discovered in the Middle Cenomanian of Lebanon.
THE CENOMANIAN FOSSIL FAUNA FROM SOUTH MOROCCO:
These specimens were discovered, not many years ago, in deposits belonging to a new and recently identified Fossil Lagerstatte at the top of Gara Sbaa slope, located in Daoura SW Morocco. These fossiliferous levels are known in litterature as the Upper Cretaceous Kem Kem beds (Sereno et al.,1996). The sediments shaping a wide arc, emerging from NE to SE for an extension of 250 km and they are marked to N by Tafilalt are and to S by "Hamada de Kem Kem".
The studied area, is formed by a poorly sedimentary series, located at the top of a small mesa, known as Gara Sbaa.
The Kem Kem beds rest unconformably on Paleozoic deposits and they are divided into two units (lower and upper units), with a total thickness of 200 m. The non-marine lower unit includes the dinosaur bed-bones, while the upper is made of sandstones, detrital channels, clay-beds and dinosaur track key bed on the top.
The upper unit is covered by marine deposits of platform (limestones) of the transgression Cenomanian-Turonian. Sereno suggested a Cenomanian age for the Kem Kem beds.
The lithology and the fauna assemblage suggest an enviroment of inshore lagoon during Albian-Cenomania age, with the formation of an enclosed proximal reef of wide platform during the Cenomanian-Turonia age.
However, the new sedimentary levels, covering the upper unit of Kem Kem bedslay directly on the Cenomanian-Turonian limestones.
THE FOSSIL FAUNA:
Beside the decapod crustaceans, isopods, xiphosurans (firs report in N Africa), tanaideacean peracarids, rare insects (Orthoptera and Omoptera), traces of marine worms, rare pelagic crinoids (Comatulidae), rare teeth of Chondrichthyes Lamniformes, and many well preserved specimens of Actinopterigians are present.
Among the marine vertebrate, we report many specimens of the Order Amiiformes still indeterminate as well as undeterminate specimens of the Order Clupeiformes closely related to the Lebanes forms and other belonging to the Orders of Pycnodontiformes, Macrosemiiformes, Aulopiformes and many other totally new genus and species.
Finally, well-preserved leafy branches and leaves are also discovered.
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