Species: canadensis DENISON, 1963
Etymology:

Holotype: Princeton University, PU 17090

Locality: Beaver River, 60?27’N lat., 125?46’W long., Southeastern Yukon Province, Canada.

Horizon:

Biostratigraphy:

Age: Downtonian (?), Silurian.

Mateiral: Nearly complete dorsal shield.

Referred material:

FMNH PF 3296: Cast of type.

= Ptomaspis cf. P. canadensis DINELEY & LOEFLER, 1976

NMC 21423

Locality: GSC 69017, 63?25’N, 128?00’W, west of Natla River, Northwest Territories Province, Canada.

Horizon: 38m above the base of the Delorme Formation.

Biostratigaphy:

Age: Late Silurian or Early Devonian.

Material: Interior mould of dorsal shield with fragments of skeletal material preserved on rotral margin and posterior-lateral corners of shield.

Note: Brackish water lagoon.