Titanosaurian teeth from the Upper Cretaceous of “Lo Hueco” (Cuenca, Spain)

Abstract

The Upper Cretaceous fossil site of “Lo Hueco” (Cuenca, Spain) has yielded two morphotypes of sauropod teeth referable to Titanosauria. One (“Lo Hueco” morphotype A) is composed of robust spatulate crown teeth. These teeth exhibit the same morphology and microwear patterns in the apical facet as teeth described from the Massecaps site (Upper Cretaceous of southeastern France). The second morphotype (“Lo Hueco” morphotype B) comprises gracile spatulate teeth similar to those of the French titanosaur genus Atsinganosaurus. However, further analysis of skeletal and cranial elements from “Lo Hueco” and its association with the described dental morphotypes will be needed to establish the degree of proximity between the Iberian and French taxa.The presence of at least two more titanosaurian taxa in the Iberian Peninsula, besides the well-known species Lirainosaurus astibiae, corroborates the increase in the known diversity of the sauropod faunae from the Upper Cretaceous of the Ibero-Armorican Island suggested by previous studies on the biota of “Lo Hueco”. In addition, the microwear differences found in the apical wear facets of the two morphotypes could be explained as due to different diets. The absence of isolated pits and the orientational consistency of the scratches support the hypothesis of a non-selective diet on soft stems, as herbaceous plants, for the titanosaurs from “Lo Hueco”. However, the presence of a coarser pattern in morphotype B suggests a niche partition for both species.