Two new species of Constrictoceras nov gen. (Ammonoidea) from the Early Cretaceous (Aptian) of Hungary

摘要

The new genus Constrictoceras is described below, and is represented in Hungary by two new species: Constrictoceras foezyi sp. nov. and Constrictoceras steineri sp. nov. According to morphological similarities, they are provisionally assigned to Acanthohoplitinae, but the lack of sutures cannot keep us from the idea of a possible relationship with Puzosiinae or Silesitidae, therefore its phylogenetic position of Constrictoceras gen. nov. is uncertain. Morphologically similar forms are described from the Aptian of Madagascar (Collignon, M., 1962) and from the Middle Aptian of Colombia (Sharikadze et al., 2004). Stratigraphical and paleobiogeographical use is very limited for the new genus.