Upper Cretaceous marine sites of the Haţeg Country Dinosaur Geopark

The Haţeg Country Dinosaur Geopark is located in the central part of Romania, being famous for its continental macrofaunas in general, and for its Upper Cretaceous (Maastrictian) dinosaur fossils in special. However, in this geopark there are also significant sites of Upper Cretaceous deposits that contain abundant and various marine fossils. Among them, there are two palaeontologically-important sites, namely the Snail Hill from Ohaba-Ponor and the Rudists from the Strei Valley, both of them being located in the SE part of Haţeg Country Dinosaur Geopark. The Snail Hill exposes a sequence spanning the Early Cenomanian-Early Turonian interval. This age was assigned based on the identified calcareous nannoplankton assemblages, containing, among other taxa, Quadrum gartneri, Q. intermedium, Eprolithus floralis, Lithastrinus septenarius and Helenea chiastia. The oldest Cenomanian deposits are sandstones and calcarenites with numerous taxa of Actaeonella, mostly belonging to A. lamarki, A. conica and A. goldfussi species. Other rudist taxa of the Cenomanian deposits exposed in the Snail Hill from Ohaba-Ponor are Durania connectens LUPU 1966, Eoradiolites sp., Eoradiolites triangularis ORBIGNY 1842, Fossulites sp., Medeella sp., Neocaprina gigantea GEMMELLARO 1865, Praeradiolites fleuriaui ORBIGNY 1842, Sauvagesia praesharpei TOUCAS 1909, Sauvagesia sp., Sphaerucaprina sp., Sphaerulites astrei LUPU 1966, Sphaerulites foliaceus LAMARCK 1815. In the marlstones that overly the Actaeonella coquina, specimens of the ammonite Mantelliceras mantelli (indicative for the upper part of the Early Cenomanian), as well as other macrofaunal taxa, such as Nerinea parva, Pecten acuminatus, Exogyra columba, E. conica, Modiola polygona, Lopha carinata and Puzosia sp. are present. Mollusc genera, such as Aporrhais, Protocardium and Panopea, could be also found. Upwards, the marlstones and claystones of the Snail Hill from the Ohaba-Ponor contains the ammonite species Acanthoceras rhotomagense, Acanthoceras jukes-brownei and Eucalycoceras pentagonum indicating a Middle-Late Cenomanian age, together with abundant other macrofaunas, especially molluscs. Another marine Upper Cretaceous palaeontologically-important site is represented by the Rudists exposure from Strei. There, a sequence of marine Upper Cretaceous sedimentation, consisting of Actaeonella- and Hippurites-bearing conglomerates and sandstones of the Strei Formation, is exposed. These are the youngest Cretaceous marine sediments of the SE part of the Haţeg Country. The rudist fauna, comprising mostly Hippurites lapeirousei (GOLDFUSS), Hippurites nabresinensis FUTTERER and Hippurites cf. colliciatus WOODWARD, dates these deposits as Santonian–Campanian, but the sandstones contain Campanian nannofloras. Therefore, probably the age of the exposed sequence is Campanian. Both above-described sites add a significant palaeontological value to the geological heritage of the Haţeg Country Dinosaur Geopark. These sites are important geological patrimonial resources that are able to generate tourist, cultural and scientific activities.