Phylogenetic placement and description of an extinct genus and species of kitefin shark based on tooth fossils (Squaliformes: Dalatiidae)

In this study we describe a new kitefin shark (Dalatiidae) genus and species Dracipinna bracheri gen. et sp. nov. based on upper Oligocene and lower Miocene tooth fossils. The teeth were excavated at three different sites which all lie in transgression phases. The fossil shark teeth are diverse and, depending on the excavation site, indicate pelagic to mesopelagic habitats. As these fossils were not found in older or younger sediments, we suggest a patchy distribution of the species. The fossils show several dental morphological characteristics of extant Dalatiidae. Phylogenetic analyses of combined morphological and DNA sequence-based data set suggest a weakly supported sister-group relationship of D. bracheri to extant Dalatiidae. Based on the dental morphological characters, we assign the dentition to a tearing type, which is rare among squaliform sharks and only known from a single extant species with a pelagic lifestyle.