Genus: Thalattosaurus MERRIAM, 1904
Etymology:
= Scenodon MERRIAM, 1905
Etymology:

Species: alexandrae MERRIAM, 1904
Etymology:

Holotype: UCMP 9085

Locality: UCMP locality 1013, Bear Cove, Sec. 34, T35N, R2W, Lying between Squaw Creek and Pitt River, northern part of Shasta County, California.

Horizon: Hosselkus Limestone.

Biostratigraphy:

Age: Carnian Stage, Lower Late Triassic Epoch, Late Triassic.

Material: Skull missing posterior end, right quadrate, cervical, dorsal and caudal vertebrae, coracoid, scapula, humerus, ulna, radius, ischium, and ribs.

Referred material:

UCMP 9084: Posterior part of skull and mandible, vertebrae, pubis? humerus and radius.

HILTON, 2003

UCMP 10815: Teeth.

UCMP 9045: Pubis.

UCMP 9044: Pubis?

UCMP 9121: Mandible with teeth.

UCMP 39226: Right upper mandible and lower mandible.

UCMP 10628: Teeth.

UCMP 9123: Posterior premaxilla.

UCMP 11228: Mandible with teeth.

UCMP 39266: Skull.

NICHOLLS, 1999

USNM 10926: Incomplete skull and mandible, lacking region anterior to naris.

UCMP 9122: Isolated vomer,

UCMP 9126: Quadrate.

UCMP 8123: Premaxilla.

 

= Thalattosaurus perrini (MERRIAM 1905)

Locality: Smith Cove, near Squaw Creek, northern part of Shasta County, California.

Horizon: Hosselkus Limestone.

Biostratigraphy:

Age: Carnian Stage, Lower Late Triassic Epoch, Late Triassic.

Material:

CAS 66236.01: Vomer.
Note: Not type.

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Species: perrini (MERRIAM, 1905) (nomen nudum)
= Scenodon perrini MERRIAM, 1905
Etymology:

Holotype: Unknown, and lost.

Locality: Smith Cove, near Squaw Creek, northern part of Shasta County, California.

Horizon: Hosselkus Limestone.

Biostratigraphy:

Age: Carnian Stage, Lower Late Triassic Epoch, Late Triassic.

Material: Dentary, maxilla, prefrontal, frontal, palatine, splenial, articular, supra-angular, angular, teeth, prevomer, and rib.

Referred material:

NICHOLLS, 1999

UCMP 10620: A small dentary.

 

= Paralonetes sp NICHOLLS & BRINKMAN, 1993 (as per NICHOLLS, 1999)

Locality: "T" crique, near Wapiti Lake, 54'31"10'"N, 120'43"19'"W, British Columbia Province, Canada.

Horizon: Sulphur Mountain Formation.

Biostratigraphy:

Age: Griesbachian to Spathian in Stage, Upper Scythian Epoch, Late Early Triassic.

Material:

RTMP 89.126.2: Disarticulated elements including maxilla, premaxilla, jugal, incomplete pterygoid, dentary, prootic, unidentified elements and isolated vertebrae and ribs.

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Species: borealis NICHOLLS & BRINKMAN, 1993
Etymology: Latin, borealis, "northern."

Holotype: RTMP. 89.126.1

Locality: South west side of "T" crique, near Wapiti Lake, 54'30"44'"N, 120'42"22'"W, British Columbia Province, Canada.

Horizon: Sulphur Mountain Formation.

Biostratigraphy:

Age: Griesbachian to Spathian in Stage, Upper Scythian Epoch, Late Early Triassic.

Material: Anterior part of skull, from tip of snout to orbital region, preserved in right lateral view, and incomplete mandible, left pterygoid, and isolated ribs and centra.