Gregoriidae is an extinct family of early chondrichthyans from the Carboniferous period. It currently includes three described genera: Gregorius, Srianta, and Bealbonn. This family includes remains formerly ascribed to the genus Desmiodus, which is now considered a nomen vanum or nomen dubium. The relationships between the included genera are not entirely clear.Grogan, E. D., & Lund, R. (2008). A basal elasmobranch, Thrinacoselache gracia n. gen and sp.,(Thrinacodontidae, new family) from the Bear Gulch Limestone, Serpukhovian of Montana, USA. Journal of Vertebrate Paleontology, 28(4), 970–988. Fossils are known from Serpukhovian-aged formations including the Bear Gulch Limestone and Surprise Canyon Formation.John-Paul M. Hodnett, David K. Elliott; Carboniferous chondrichthyan assemblages from the Surprise Canyon and Watahomigi formations (latest Mississippian–Early Pennsylvanian) of the western Grand Canyon, Northern Arizona. Journal of Paleontology; 92 (S77): 1–33.
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