Genus: Placerias LUCAS, 1904
Etymology: Greek, plakeros, “broad”, Greek, -ias, (in character): Broad body.

Species: hesternus LUCAS, 1904
Etymology:

Holotype: USNM 2198

Locality: Ward’s Bonebed, 3 miles north of Tanners Crossing of the Little Colorado River, Petrified Forest, Apache County, Arizona.

Horizon: Lower Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material: Right humerus.

Topotype: MNA V 8464

Locality: MNA Locality 1454, along Ward’s Terrace, east of Cameron and just north of Landmark Wash at UTM Zone 12, 472000E, 3964620N, Apachae County, Arizona.
Note: Found near the type specimen.

Horizon: Lower Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material: Maxillary, orbital region and squamosal region, especially of the left side. (LUCAS, HECKERT & ESTEP, 1999, LUCAS & HECKERT, 2002)

Referred material:

CAMP & WELLES, 1956

UCMP V3309: Fragment of a small squamosal.

UCMP V4121: Fragmentary scapula.

 

HUBER, LUCAS & HUNT, 1993, LUCAS, 1998

Locality: Pomona Pipe Products Pit, Gulf, Deep River Basin, Wadesboro sub-basin, North Carolina.

Horizon: Middle Pekin Formation, Chatham Group.

Biostratigraphy:

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

Material:

AMNH 2848, 2854, 2853, 2857, 2859, 2863, 2864, 2868, 24112: Assorted vertebrae.

AMNH 2849, 2850,2851, 24142, 24125: Ribs and rib fragments.

AMNH 24118, 24119: Humerus fragments.

AMNH 24126-24137, 2845-2847: Bone fragments.

AMNH 2852: Partial articular.

AMNH 2855: Distal end of tibia.

AMNH 2856: Scapula fragment.

AMNH 2858: Left articular.

AMNH 2859: Vertebrael fragments.

AMNH 2860: Proximal part of a femur.

AMNH 2861: Sacral vertebrae.

AMNH 2866: Left femur.

AMNH 2867: Shaft of left humerus.

AMNH 2869: Partial quadrate.

AMNH 2871: Incomplete squamosal.

AMNH 2872: Right maxillary.

AMNH 2873: Left squamosal.

AMNH 2874, 2876: Fragments of left humeral shaft.

AMNH 2875: Fragment femoral shaft.

AMNH 2877: Partial left radius.

AMNH 2878: Shaft of right humerus.

AMNH 2879: Phalanx.

AMNH 2880: Distal end of right humerus.

AMNH 2881: Left maxillary.

AMNH 2883: Left articular.

AMNH 2884: Left quadrate.

AMNH 2885: Portion of occupit.

AMNH 2886: partial occipital plate.

AMNH 24114: Left maxillary fragment.

AMNH 24115: Metopodial.

AMNH 24116: Squamosal fragment.

AMNH 24117: Preparietal.

AMNH 24120: Distal end of radius.

AMNH 24121: Proximal end of right radius.

BAIRD & PATTERSON, III, 1968

Number: Not given: Teeth.

 


= Placerias gigas CAMP & WELLES, 1956
Etymology:

Holotype: UCMP 27553 (A269)MX

Locality: UCMP loc A269, the Placerias quarry, in a small valley 6 1/2 miles S 65"W of St. Johns, Apache County, Arizona. Located 0.3 miles northwest of Romero Springs at approximately Long. 109'28'W and lat. 34"27'N on the USGS St. Johns quadrangle of 1921.

Horizon: Bluewater Creek Formation, Lower Chinle Group.

Biostratigraphy:

Age: Adamanian, Latest Carnian Stage, Late Triassic Epoch, Late Triassic.

Material: Right maxillary.

Referred material:

UCMP 24547, 25324, 32409, 32415 C4, 32437, 32438, 27632, 27665, 27636, 27674, 27675: Postorbitals.

UCMP 24561, 24589, 32416: Jugals.

UCMP 24633, 24642, 24657, 24675, 32401: Quadrates.

UCMP 24644, 24650, 24653, 24654, 24674, 24680, 25332, 32400: Stapes.

UCMP 24711: Articular.

UCMP 24713: Prearticular.

UCMP 24739, 24741: Dentaries.

UCMP 24746, 24761, 24762, 24766, 32404: Splenals.

UCMP 24781, 24782, 24783, 24810, 24817, 24826: Scapula.

UCMP 24823, 24824, 25444, 25446, 25447, 25448: Pubes.

UCMP 24852, 25429, 25431, 25432, 25952, 25953, 32442: Ulnae.

UCMP 24859, 26682, 32445: Radii.
Note: UCMP 32445 has tooth marks.

UCMP 24864, 24865, 24866, 24868, 24871, 24872, 32447: Tibiae.

UCMP 24875, 24876, 24878, 24882, 24883, 24890, 32446: Fibulae.

UCMP 24894, 24926, 27994, 27995, 27999: Mesopodials.

UCMP 24927, 25043, 25471: Phalanages.

UCMP 24951, 24959, 25007: Metapodials.

UCMP 25055, 25454, 32394: Femora.

UCMP 25064, 25069, 25096, 32159, 32393: Ilia.

UCMP 25087, 25093, 25094: Ischia.

UCMP 25100, 25129, 25132, 25136, 25148, 25157, 25267, 25268, 25269, 25274, 25280, 25281, 25286: Fragmentary vertebrae.

UCMP 25146: Fragmentary cervical vertebrae.

UCMP 25295: Vertebra.

UCMP 25316, 27353, 27360, 27830: Premaxillae.

UCMP 25317, 27318, 27319, 27550, 27551, 32389: Maxillae of a male.

UCMP 25346: Dorsal rib head.

UCMP 25361, 32459, 32460: Humeri.

UCMP 25442, 27699, 27709, 27712, 27720: Preparietals.

UCMP 25443: Preparietal and ulna.

UCMP 25588: Dorsal neural spine.

UCMP 25602: Cervical neural spine.

UCMP 26674, 27702, 28383, 28384, 28399: Frontals.

UCMP 26679: Parietal.

UCMP 26680, 27891, 27892, 28372, 32398: Supraocciptial, parocciptual and prootic segments.

UCMP 27532: Dorsal vertebra.

UCMP 27539, 27541, 27546, 27552, 27555, 28391, 28398: Maxillae of a female.

UCMP 27553: Left and right maxillae of a male.

UCMP 27565, 27947, 32414: Lachrymals.

UCMP 27619, 28396: Postfrontals.

UCMP 27704: Frontal, parietal.

UCMP 27721: Interparietal.

UCMP 27737, 27738, 27766, 27777, 32395, 32441: Squamosals.

UCMP 27924, 27925: Basiphenoids.

UCMP 27936, 27937: Supraoccipitals.

UCMP 28341: Surangular.

UCMP 28363, 28364: Quadratojugals.

UCMP 32402, 32403: Preparietals.

UCMP 32405: Angular.

UCMP 32410: Interparietal?

UCMP 32411: Interclavicle?

UCMP 32412: Basiocciptal.

UCMP 32420: Postfrontal?

UCMP 32448: Sternum.

UCMP 32454: Pubis of a juvenile.

UCMP 32458: Supraoccipital, basiociptal.

C62, CH2: Fragmentary skulls.

In addition to LONG & MURRY, 1995

MNA collections

MNA Pl. 2753: Left quadrate.

MNA Pl. 2769: Left articular.

MNA Pl. 2770: Squamosal fragment.

MNA Pl. 2950: Right jugal.

MNA Pl. 2951: Right jugal.

MNA Pl. 2986: Cervical centrum.

MNA Pl. 2981: Caudal vertebra.

MNA Pl. 3031: Neural arch.

MNA Pl. 2714B: Right humerus (same individual as MNA Pl. 2714A).

MNA Pl. 2878: Right humerus in 2 pieces.

MNA Pl. 2714A: Right ulna.

MNA Pl. 2713: Right femur.

MNA Pl. 2820: Ungual.

MNA Pl. 3011: Ungual phalange.

MNA Pl. 3023: Phalange.