Distribution Geographic
Morphological characteristics
Medial teeth
Teeth from medial files are up to 5 mm high and 3.7 mm wide, and have a nearly symmetrical crown with an upright, pointed principal cusp. The cusp is lingually inclined. On the heels, 1-2 or rarely 3 pairs of low, triangular cusplets are present. The labial crown base is almost flat or forms a slightly convex overhang. The root has a pronounced lingual bulge (protuberance), but is rather thin at the marginal heels. Medial teeth tend to be smaller in size (height and width) than anterior and antero-lateral teeth. Their height-to-width ratio and depth-to-width ratio is similar to that of anterior teeth.
Anterior teeth (without clear assignment to upper or lower jaw)
Teeth with a slender, acute main cusp, narrow to broad heels and a thick root. The labio-lingual diameter of the principal cusp at its base equals or exceeds the mesio-distal diameter. The main cusp is strongly bent lingually and forms an angle of 45-60° with the basal face of the root. The distal inclination of the cusp is variable; it tends to be higher in teeth with a broader root base.
The labial and lingual crown faces are smooth, lacking ornamentation. The labial crown face is convex. The curvature of the lingual face is strong, displaying subparallel marginal faces near the crown base. The basal labial crown overhang is weak. The cutting edges continuously extend from the apex to the margins of the heels, which form high ridges with labio-lingually narrow, convex faces. The cutting edges of the ridges are smooth; they pass into the margins with a convex bow or form a broad cusplet on the distal heel. In occlusal view, the distal heel and, less commonly, the mesial heel is recurved lingually. In labial and mesial view, the mesial cutting edge of the main cusp shows a sigmoid, flexuous course. The distal cutting edge is straight to convex; its curvature is less flexuous than the mesial cutting edge.
The root lobes meet at an angle of 180° and are hardly separated. In the most anterior teeth the root is as wide as labio-lingually thick. In more lateral files the root width increases, whereas its thickness remains almost unchanged. Generally, the root is asymmetric and has the shape of a distally inclined parallellogram, whose mesial and distal flanks are constricted. The lingual bulge is very thick and salient and forms the solid base of the robust crown (see above). The basal root face is convex in teeth of the most anterior files and rather flat or irregularly shaped in teeth of more lateral files. The nutrient groove is variably deep and contains one to three larger foramina, sometimes also additional smaller foramina. The paratypes (P 9692, P 9693, P 9694) show the characteristics of anterior teeth. Anterior teeth tend to show higher height-to-width ratios than anterolateral teeth. Anterior teeth clearly differ from antero-lateral teeth by a higher depth-towidth ratio mainly because of their thicker root.
Antero-lateral teeth of the upper jaw
Teeth with a slender, sigmoid principal cusp on a broad base, with low, but distinct cusplets on the distal heel and a moderately thick and low root. The cusp is inclined at 70 to 45° in distal direction. The inclination of the cusp moderately increases while the teeth become lower towards the commissure. The crown faces are smooth and convex, the lingual face being much more convex than the labial one, but not as extreme as in the anterior files. In profile or occlusal view, the teeth show a flexuous labial crown face, characterised by a subcircular bulge at the base, a thin, labially recurved crown tip and a sigmoid bend of the mesial cutting edge.
The mesial cutting edge runs smoothly from the apex to the outer margin of the mesial heel. Some notches or low cusplets rarely occur at the outer mesial heel. The distal cutting edge of the cusp is slightly convex, sometimes even straight or sigmoid. Separated from the cusp by a concave or acute notch, the distal heel bears two or three (rarely up to five) low cusplets which are distally inclined and decrease in size distally.
The root is only slightly broader than the crown base. It is moderately strong and rather low. Its lingual bulge is less developed than in anterior teeth. Labially, the root is weakly concave, whereas its basal face is almost flat. Lingually, the crown-root junction is marked by a transversal groove. 1-2 foramina join the nutrient groove, which is open and rather flat. Numerous small foramina may also be present along the base of the labial and lingual root faces.
The holotype, an upper left antero-lateral tooth, shows a high, narrow cusp that is inclined at an angle of 50° toward the commissure. The mesial cutting edge has a sigmoid outline, whereas the distal cutting edge is straight to slightly convex near the apex. The tooth has broad heels. Three low cusplets, well separated from the main cusp, are present on the distal heel. Antero-lateral teeth of the lower jaw
The antero-lateral teeth of the lower jaw resemble the teeth of the upper jaw, except for the following features: the mesial cutting edge is markedly concave and the crown tip is generally directed upward. Some teeth may have a minor bend in the course of the mesial cutting edge. The mesial heel is relatively wider and less inclined than in comparable upper teeth. Teeth from very lateral and postero-lateral files have an almost vertical distal cutting edge which in combination with the strongly concave mesial edge gives the teeth a hook-like shape. The cusplets on the distal heel tend to be lower and less regular than in upper files. Rarely, cusplets are lacking and a low, straight or convex enamel board is present on the distal heel. In teeth of the lower jaw the labial crown face is less flexuous than in those of the upper jaw, i.e. the crown tip is straight or only slightly bent in lingual direction. A labial recurvature of the crown tips is only seen in the most anterior files. The paratypes P 9695 and P 9696 are antero-lateral teeth of the lower jaw. Lower und upper antero-lateral teeth have quite similar dimensions.

Remarks
shark-references Species-ID=10855;

References