This is one of the star pieces of our Mosasaurus collection. It is the distand end of a jaw from Eremiasaurus heterodontus. This piece comes from the Upper Cretaceous famous phosphate quarries of the Ouled Abdoun Basin (Morocco). The specimen is in its original sedimentarian matrix.
Matrix dimensions: 310 x 222 x 80 mm (12.2 x 8.7 x 3.1 in)
Jaw dimensions: 204 mm (8.03 in) long
The rests of Mosasaurus jaws in this sector of Morocco are relatively common. However, it is extremely difficult to discover jaws which still have their teeth in their original position. Usually this type of pieces are mounted out of single teeth and jaw fragments without teeth. However, this piece is not a composition. This is an absolutely original piece. It does not have any restoration or reparation. It has only been excavated from the matrix in order to make it visible. It has not even been treated with stabilizers. It is displayed as it was discovered.
It is 100% original and authentic.
The piece has both hemi-jaws from the animal: the right hemi-jaw and the left hemi-jaw. We know the position of each of the hemi-jaws thanks to the preserved mandibular symphysis. The right mandibular branch is overlapped on the left one.
The right hemi-jaw preserves 5 teeth in its original position, including the symphysial tooth (one of the ones which would be located in the snout).
The teeth are between 30 and 45 mm (between 1.18 and 1.77 in).
We can observe the continuity of the teeth until the jaw and the corresponding jaw holes. The texture of the superficial anatomy of the bone is extremely well defined.
The left hemi-jaw preserves 3 full teeth and a partial one. Additionally, a tooth is preserved slightly out of its original position. Note the natural rugosity of the symphysial area in the distand end of this hemi-jaw.
The matrix contains as well other associated bone rests. We can observe several Selachii vertebrae distributed across the matrix, as well as some emerging shark teeth.
Without doubt, this is an exceptional exhibition piece.
The morphology of the jaw as well as their teeth tell us that it corresponds to the Mosasaurus taxon belonging to the Eremiasaurus heterodontus species.
To read more about this type of Mosasaur (which was recently described), you can read the following reference from its authors:
A. R. H. LeBlanc, M. W. Caldwell, and N. Bardet. 2012. A new mosasaurine from the Maastrichtian (Upper Cretaceous) phosphates of Morocco and its implications for mosasaurine systematics. Journal of Vertebrate Paleontology 32(1):82-104
In the international market is very common to find Mosasaurus rests coming from the phosphate quarries of the Upper Cretaceous of the Ouled Abdoun Basin (Morocco).
This quarries have been exploited since the beginning of the past century. Many sellers that sell this fossils do not make a good precise taxonomic identification work.
In these sites there are numerous different species of Mosasaurus described in the enormous assemblage of giant marine reptiles that reigned the seas during the Cretaceous.
The main rich levels in these paleontological taxons are in the deeper stratigraphic levels of the sedimentarian filling of the Ouled Abdoun Basin. The age of these correspond to the Maastrichtian stage, 66 million years ago.
Most of the research carried out on these marine reptiles from Morocco have been performed by French researchers.
Next we list the different Mosasaur species which have been recognised in the phosphate rocks in North Africa:
-Halisaurus aramborgi (Bardet et al., 2005)
-Halisaurus walkeri (Lingham-Solier, 1998)
-Prognathodon sp (Dollo, 1889)
-Prognathodon anceps (Leiodon anceps)
-Prognathodon solvay (Dollo, 1889)
-Prognathodon currii (Christiansen & Bonde, 2002)
-Eremiasaurus heterodontus (LeBlanc et al., 2012)
-Mosasaurus beaugei (Arambourg, 1952)
-Mosasaurus hoffmanni (Mantell, 1829)
-Tylosaurus (Marsh, 1872)
-Platecarpus ptychodon (Arambourg, 1954)
-Globidens phosphaticus (Bardet et al., 2005)
-Carinodens belgicus (Bardet et al., 2005)
The Ouled Abdoun Basin (or Khouribga Basin), located in the central sector of Morocco, is an enormous sedimentarian basin represented mostly by a vast filling of phosphate sediments. Apart from having a relevant raw material to be extracted, it has a series of very important paleontological sites in which amazing assemblages from big and small marine vertebrates are present. The basin has a so great continuity in its stratigraphic record that both the Upper Cretaceous as well as the two first epochs of the Paleogene (Paleocene and Eocene) can be studied.
The main assemblage of vertebrate fossils of the Paleogene sector present there is composed by sharks, fish, turtles, marine snakes, rays, crocodiles, other types of reptiles and even marine birds. In the Cretaceous part we can add Mosasaurs, Pterosaurs and Plesiosaurs.
Next you can visit a link with very interesting information about this sedimentarian basin rich in fossil vertebrates: Ouled Abdoun Basin