A unique diversity hotspot for Polycopidae (Ostracoda) in the Triassic of North Dobrogea

Abstract

ABSTRACT The present contribution explores the diversity of Early-Middle Triassic Polycopidae in North Dobrogea, Romania. Abundant and well-preserved specimens have been obtained from samples collected from the Deşli Caira section, adding unique scientific understanding of these often overlooked taxa in the fossil record. Their taxonomy is discussed, the first Triassic record of the genus Pontopolycope is reported and five new species are described (Polycope lazarusi Forel sp. nov., P. legio Forel sp. nov., P. ludwigi Forel sp. nov., Pontopolycope jeanlouisi Forel sp. nov., Pt. papai Forel sp. nov.). Issues regarding the orientation of species previously reported from the nearby Uzum Bair section are identified and the diagnosis of Polycope baudi, P. niculae and Pontopolycope densoreticulata are emended. For the first time, we describe the ontogenetic development of six species of Polycopidae and report on the occurrence of at least two species showing precocious sexual dimorphism. The high diversity of the Polycopidae assemblages from the North Dobrogea in the Early and Middle Triassic led us to consider this area as a biodiversity hotspot for these ostracod taxa.