Daouitherium rebouli

Tabuce, Rodolphe, Delmer, Cyrille & Gheerbrant, Emmanuel, 2007, Evolution of the tooth enamel microstructure in the earliest proboscideans (Mammalia), Zoological Journal of the Linnean Society 149 (4), pp. 611-628 : 616

DAOUITHERIUM REBOULI

In a vertical section of a m3 tooth, the enamel thickness is around 1500 µm. The Schmelzmuster is entirely constituted by HSB from the EDJ to the OES ( Fig. 3C ). The HSB run straight outwards and are parallel to each other; they are of variable width, varying in the sample from seven to 20 prisms. Very few bifurcations of HSB occur. In horizontal sections of a fragment removed from a m2 tooth, the prism cross sections present a rounded pattern near the OES. In the inner zone, the prism cross sections vary from a keyhole pattern (the prisms are basally opened and densely packed) to an arc pattern (the prisms are also basally opened, but not densely packed, and they present an important amount of IPM of the enamel) ( Fig. 3B ); in this zone, the diameter of the prisms is around 5–7 µm. Near the EDJ, the prisms cross sections were not observed. A tangential view of the same specimen shows decussations of low amplitudes; bundles of prisms appear. On an enamel fragment removed from the unique known molar of Daouitherium sp. , the enamel thickness is around 350 µm; the Schmelzmuster is identical to that of D. rebouli .

Figures

Figure 3. A, Moeritherium chehbeurameuri, late–middle Eocene, Bir El Ater, Algeria; vertical section of a lower molar showing a two-layered Schmelzmuster with radial enamel in the outer zone underlain by Hunter-Schreger bands (HSB) in the inner two thirds; EDJ, enamel dentine junction. B, Daouitherium rebouli, earliest Eocene, Ouled Abdoun Basin, Morocco; horizontal section of a lower molar with open-prism cross sections and an important amount of interprismatic matrix (IPM). C, vertical section of a lower molar of the same species showing HSB that reach the outer enamel surface (OES).