Genus: Archaeothyris REISZ, 1972
Etymology:

Species: florensis REISZ, 1972
Etymology:

Holotype: MCZ 4079

Locality: Dominion Coal Company, strip mine no. 7, 2 miles north of Florence, Cape Breton County, Nova Scotia Province, Canada.

Horizon: Morien Group, within 25 feet above the Lloyd Cove Coal seam, equivalent to the Westphalian D of Europe.

Biostratigraphy:

Age: Westphalian D, Lower Upper Silesian, Desmoniensean, Myachkovskian Stage, upper Moscovian Epoch, Late Pennsylvanian (Late Carboniferous).

Material: Partial skull, several vertebrae, humerus, and cervical ribs.

Referred material:

MCZ 4080: Pelvis, sacral vertebrae and axis.

MCZ 4081: Caudal vertebrae.

MCZ 4082: Anterior dorsal vertebrae.

MCZ 4083: Assorted postcranial elements.

MCZ 4084: Caudal vertebrae.

MCZ 4085: Lower jaw elements and frontal.

MCZ 4086: Metacarpals.

MCZ 4087: Presacral vertebrae.

RM 10056: Maxilla, dentary, presacral and caudal vertebrae, interclavical, calcaneum.