Full reference: R. Lund and E. Grogan. 2004. Five new euchondrocephalan Chondrichthyes from the Bear Gulch Limestone (Serpukhovian, Namurian E2b) of Montana, USA. Recent Advances in the Origin and Early Radiation of Vertebrates 505-531
Parent taxon: Euchondrocephali according to R. Lund and E. Grogan 2004
Sister taxa: Chimaeri, Debeeriformes, Debeeriiformes, Delphyodontos, Edaphodus, Eugeneodontiformes, Helodontiformes, Holocephalomorpha, Iniopterygiformes, Macrodontacanthus, Menaspacanthus, Orodontiformes, Paraselachiamorpha, Paraselachimorpha, Petalodontiformes, Thoralodus, Trachyacanthi, Pseudodontichthyidae, Desmiodus, Euglossodus, Mesolophodus, Ageleodus, Cynopodius, Metaxyacanthus, Lagarodontidae, Brachyrhizodus
Subtaxa: Bealbonn Gregorius Srianta
Type: Gregorius
Ecology: nektobenthic carnivore
Distribution: found only at Bear Gulch Limestone Lens (Carboniferous of Montana)