Chondrichthyes - Hybodontiformes - Sphenacanthidae
Synonym: Xenosynechodontidae Glikman 1980
Parent taxon: Hybodontiformes according to R. van der Laan 2019
See also Ginter et al. 2010, Ivanov 1999, Ivanov et al. 2013 and Tverdokhlebov et al. 2005
Sister taxa: Cassisodus, Doratodus, Hamiltonichthys, Hubeiodus, Hybodontidae, Hybodontoidea, Mesodmodus, Omanoselache, Onychoselache, Pseudodalatiidae, Reesodus, Steinbachodontidae, Teresodus, Thaiodontidae
Subtaxa: Khuffia Sphenacanthus Xenosynechodus
Type: Sphenacanthus
Ecology: nektonic carnivore
Distribution:
• Tatarian of the Russian Federation (4 collections)
• Permian of Brazil (2), Oman (8), the Russian Federation (13), United States (3: Texas)
• Carboniferous of the United Kingdom (2), United States (2: Illinois, Texas)
• Devonian of the Russian Federation (1)
Total: 35 collections including 42 occurrences