Genus: Pessosaurus WIMAN, 1910
Etymology: Greek, pessos, “round stone game-piece for playing draughts or checkers”, Greek, sauros, “lizard”: Game-piece (fin) lizard.
= Ekbainacanthus YOKOWLEW, 1903
Etymology: Greek, ekbaino, “go out, exceed” and Greek, akantha, “spine” + us: Outward projecting spine.

Species: polaris (HULKE, 1873) WIMAN, 1910
Etymology:
= Ichthyosaurus polaris HULKE, 1873
= Ichthyosaurus (Mixosaurus) polaris (HULKE, 1873) DAMES, 1895
= Shastasaurus polaris (HULKE, 1873) YAKOWLEW, 1902
= Cymbospondylus (?) polaris (HULKE, 1873) MERRIAM, 1908
= Ichthyosaurus (Shastasaurus) polaris (HULKE, 1873) MERRIAM, 1902

Holotype:

Locality: Isfjord, Spitsbergen, Svalbard Island, Norway.

Horizon:

Biostratigraphy:

Age: Late Triassic.

Material: Coracoid, left radius, humerus, femur, and vertebrae.

Referred material:

MAZIN, 1984

Locality: Mount Kongress, Dickson Land, Spitsbergen, Svalbard Island, Norway.
Horizon:

Biostratigraphy:

Age: Ladinian Stage, Upper Mid Triassic Epoch- Carnian Stage, Lower Late Triassic Epoch, Late Triassic.

Material: Fragment of mandible with teeth.

SVT 329: Fragment of mandible and dentary with teeth.

 

= Ekbainacanthus tschernyschewi YOKOWLEW, 1903
Etymology:

Holotype:

Locality: Spitsbergen, Svalbard Island, Norway.

Horizon: From a layer above the upper Sticky Keep Formation, Upper Saurian Nieveau.

Biostratigraphy:

Age: Near the Ladinian-Carnian boundary, Late Triassic.

Material: Ischium, tooth fragment and several vertebrae and ribs.
Note: The supposed scapula is most likely a rib head.

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Species: suevicus HUENE, 1916 (nomen dubium)
Etymology: Suevi, an old Germanic race.

Holotype:

Locality: Black Forest, Baden-Wurttemberg State, Germany.

Horizon: Lower Muschelkalk.

Biostratigraphy:

Age: Anisian Stage, Lower Mid Triassic Epoch, Middle Triassic.

Material: Posterior dorsal centrum.