Genus: Tenuirostria emend ARKHANGELSKY, 1998
Etymology: Latin, tenuis, “narrow”, and Latin, rostrum, “snout”; narrow snout.
= Subgenus: Tenuirostria ARKHANGELSKY, 1998

Species: americanus (NACE 1939) ARKANGELSKY, 1998
Etymology: In reference to America, the country of origin.
= Myopterygius americanus NACE 1939
= Platypterygius americanus (NACE, 1939) McGOWAN, 1972
= Platypterygius (Tenuirostria) americanus (NACE 1939) ARKANGELSKY, 1998

Holotype: University of Wyoming Geological Museum No. VP50

Locality: 2 feet below base of Clay Spur bentonite bed, NE 1/4, SW 1/4, Sec. 17, T49N, R 65W, Crook County, Wyoming.

Horizon: Uppermost part of the Mowry Member, Graneros Formation.

Biostratigraphy:

Age: Albian Stage, Lower Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous.

Material: 69 vertebral centra, 17 cervical, 14 dorsal, and 38 caudal, 2 nearly complete neural arches and spines, various fragmentary arches, 1 complete posterior dorsal rib, numerous rib head and shaft fragments, various fragmentary abdominal ribs, left scapula, distal end of right scapula, both humeri, right and left ulnae and radii, right intermedium and ulnare, 17 miscellaneous phalangeal elements, possibly representing parts of all paddles, right (?) sichiopubis and lower or articular part of right (?) ilium, and both femora.

Referred material:

ROMER

Locality: Near Ostage, Wyoming.

Horizon: Mowry Shale.

Biostratigraphy:

Age: Albian Stage, Lower Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous.

Material:

UW 2421: Skull.

 

MASSARE & DAIN, 1989, LOPUCHOWYCZ & MASSARE, 2002

Locality: Near Upton, Weston County, Wyoming.

Horizon: Mowry Shale.

Biostratigraphy:

Age: Albian Stage, Lower Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous.

Material:

UW 32393-32395: Fragmentary specimens.

 

MAXWELL & KEAR, 2010

Locality: Wyoming.

Horizon: Belle Fourche Shale.

Biostratigraphy:

Age: Middle Cenomanian Stage, Gallic Subepoch, Lowermost Gulf Epoch, Middle Cretaceous.

Material:

UW 5545: Rostrum, opisthotic, stapes, rib fragments, vertebrae, partial scapula, right femur and assorted paddle elements.

 

Locality: Wyoming.

Horizon: Mowry Shale.

Biostratigraphy:

Age: Albian Stage, Lower Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous.

Material:

UW 2421: Skull, atlas-axis complex vertebrae, rib fragmetns, partial right and left scapulae, partial clavicale, humeri, articulated porximal paddle elements, and disarticulated phalangeal elements.

 

Locality: Wyoming:

Horizon: Ashville Formation.

Biostratigraphy:

Age: Albian Stage, Lower Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous-Cenomanian Stage, Gallic Subepoch, Lowermost Gulf Epoch, Middle Cretaceous.

Material:

CMN 10424: Partial rostrum.

= Myopterygius petersoni NACE, 1941
Etymology:

Holotype: University of Wyoming, Geological Museum, No. VP-190

Locality: SW part of Sec. 25, T48N, R 65W, Weston County, Wyoming.

Horizon: Base of the Belle Fourche shale Member, Granerous Formation.

Biostratigraphy:

Age: Albian Stage, Lower Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous.

Material: Large fragment of an unidentified skull, stapes and paroccipital (?) bones, teeth in place in the alveolar grooves of the rostrum, 2 complete anterior dorsal centra and 1 fragment of an anterior dorsal centrum, 1 complete and 3 incomplete posterior dorsal centra, 2 anterior and 3 posterior caudal centra, 1 dorsal rib, various rib heads and fragments of rib shafts, right scapula, right femur and 26 miscellaneous phalangeal elements.

_____________________________________________________________________________________