Oogenus: Mazonova GODFREY, 1995
Etymology: A combination of “Mazon” in reference to Mazon Creek, Illinois, the general locality where these fossils were collected and Latin, ova, “eggs”: “Mazon eggs”.

Oospecies: helmichnus GODFREY, 1995
Etymology: A combination of “Helmus” in honour of Karlene Ramsdell (nee Karlene Helmus) and her sister, Mary Pat Smith (nee Mary Pat Helmus) for their devotion to the collection and preservation of Mazon Creek, fossils, and Latin, ichnus, “trace”.

Holotype: ROM 47490

Locality: Known only from spill heaps of Pit 11 of the now abandoned strip mine of the Peabody Coal Company, Will-Kankakee Counties, Illinois.

Horizon: Carbondale Formation, Frances Creek Shale.


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

Material: String impressions of eggs.
Note: May not belong to an labyrinthodon.