A Sauropod Tooth from the Santonian of Hungary and the European Late Cretaceous \u2018Sauropod Hiatus\u2019

Attila Ősi,Edina Prondvai,Zoltán Csiki-Sava

doi:10.1038/s41598-017-03602-2

Abstract

The lack of sauropod body fossils from the 20 My-long mid-Cenomanian to the late Campanian interval of the Late Cretaceous in Europe is referred to as the ‘sauropod hiatus’, with only a few footprints reported from the Apulian microplate (i.e. the southern part of the European archipelago). Here we describe a single tooth from the Santonian continental beds of Iharkút, Hungary, that represents the first European body fossil evidence of a sauropod from this critical time interval. The mosaic of derived and plesiomorphic features documented by the tooth crown morphology points to a basal titanosauriform affinity suggesting the occurrence of a clade of sauropods in the Upper Cretaceous of Europe that is quite different from the previously known Campano-Maastrichtian titanosaurs. Along with the footprints coming from shallow marine sediments, this tooth further strengthens the view that the extreme rarity of sauropod remains from this period of Europe is the result of sampling bias related to the dominance of coastal over inland sediments, in the latter of which sauropod fossils usually occur. This is also in line with the hypothesis that sauropods preferred inland habitats to swampy environments.

Highlights

We report a sauropod dinosaur tooth from the Santonian of Iharkút, Hungary, an unexpected discovery that represents the first body fossil of the clade known from this poorly sampled period of the sauropod fossil record in the European Cretaceous
The bauxite and the karstified paleosurface is covered by alluvial floodplain deposits of the Santonian Csehbánya Formation consisting of alternating coarse basal breccia, sandstone, siltstone and paleosol beds deposited in a continental environment[21]
Bones at the site are accumulated in bonebeds, among which the most productive one (SZ-6 site, Fig. 1B,C), a greyish, coarse basal breccia layer, produced most of the vertebrate remains including the tooth described in this study

Summary

Introduction

We report a sauropod dinosaur tooth from the Santonian of Iharkút, Hungary, an unexpected discovery that represents the first body fossil of the clade known from this poorly sampled period of the sauropod fossil record in the European Cretaceous. It retains the lingual concavity and a D-shaped cross section, but the tooth crown is narrow and not markedly expanded relative to the root, the labial grooves are absent, and no denticulate mesial and distal margins are present.

Results

Conclusion