Morphotype IV, Bonaparte & Novas, 1985

Morphotype IV

The morphology of the teeth referred to this morphotype is somewhat reminiscent to that seen in the lateral teeth of Noasauridae . They are similar to typical abelisaurid lateral teeth, but differ in that they are much smaller (<2 cm) and typically short (CHR <1.5). They have a small number of comparatively large denticles on both mesial and distal carinae, which are often asymmetrically convex to apically hooked. The DSDI is always close to one. The teeth have a lanceolate cross-sectional outline, a straight to weakly concave distal profile, and centrally positioned mesial and distal carinae that always extend to the root. The enamel surface texture is irregular, and there are no crown ornamentations, such as transverse or marginal undulations. The mesial and distal denticles are typically asymmetrically to distally hooked.

Identification: Specimens from morphotype IV probably represent lateral teeth from juvenile to very young abelisaurids and not noasaurids, because they differ from the latter by having crowns with a DSDI close to one.

Specimens from Uberaba, Minas Gerais state, Marília Formation : CPP 129a , CPP 129c , CPP 375-1 , and CPP 452-2 .

Specimens from Ibirá, São Paulo state, Adamantina Formation : LPP-PV 1109 , LPP-PV 1123 ( Fig. 14 View Figure 14 ), LPP-PV 1146 ( Fig. 15 View Figure 15 ), and LPP-PV 1149 .

Specimens from Prata, Minas Gerais state, Adamantina Formation: MN 6274-V , MN 6287-V , and MN 6295-V .

Specimen from Flórida Paulista, São Paulo state, Adamantina Formation : UFRJ-DG 374-Rd ( Fig. 16 View Figure 16 ).