Incertae sedis Elasmobranchii

Superregnum: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Classis: Chondrichthyes
Subclassis: Elasmobranchii
Superordo: incertae sedis
Familia: Thrinacodontidae

References

* Grogan, Eileen D. & Lund, Richard 2008; "A Basal Elasmobranch, Thrinacoselache gracia n. gen & sp., (Thrinacodontidae, New Family) from the Bear Gulch Limestone, Serpukhovian of Montana, USA" Journal of Vertebrate Paleontology 28(4):970–988,