Genus: Acaenasuchus LONG & MURRY, 1995
Etymology: Greek, akaina, "thorn," for the thorn like spikes developed on the armor and Greek, suchus, "crocodile": Thorn crocodile.
= "Acaenasuchus" MURRY & LONG, 1989 (nomen nudum)

Species: geoffreyi LONG & MURRY, 1995
Etymology: In honor of Geoffrey E. Long, son of R. A. Long, for his considerable patience while his father was away in the field.
= Acaenasuchus "geoffreyi" MURRY & LONG, 1989 (nomen nudum)

Holotype: UCMP 139576

Locality: Blue Hills 1, (UCMP 7307 and 7308), 3 miles NE of St. Johns, Apache County, Arizona.

Horizon: Lower Blue Mesa Member, Lower Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material: Paramedian plate.

Referred material:

UCMP 7308/139585-139588: Partial paramedian plate.

UCMP 7308/139590-139595: 7 lateral plates.

UCMP 7308/139596-139602: 7 lateral plates.

UCMP 7308/139577, 139578, 729579, 139580, 139581, 139582, 139583: Lateral plates.

UCMP 7308/139603-139621: 20 plate fragments.

PEFO 40711, UCMP 285903: Cranal fragment.

PEFP 38748, 40693, 40687, 40703, 40706, 40712, 40723, 40731, 40738, MNA V2877, UCMP 192558, 195222, 285836, 285856, 285858, 285875, 285904, UMNH VP 30183: Vertebrae.

PEFO 40703, 40712, 40721, 40723, 40738, UCMP 285842: Ribs.

PEFO 40720, UCMP 285840: Scapula.

UCMP 285851: Coracoid.

PEFO 40693, 40704, 40739: Humerus.

UCMP 285835: Ulna.

PEFO 16638, 40720, 40731, UCMP 285833, 2859009: Ilium.

PEFO 40693, UCMP 285841, 285851: Pubis.

PEFO 40693: Ischium.

PEFO 38762, 38763, 40696, 40720, 40734, MNA V3048: Femur.

PEFO 40731: Tibia.

PEFO 39763, 40702, 40740, 44449, MNA V3043, V3066, UCMP 139582, 175109, 175111: Articulated osteoderms.

PEFO 16621, 317181, 37185, 37223, 37326, 38363, 40000, 40694, 40706, 40742, 44448, 44450, 44452, 44455, MNA V3040, V3067, V3113, V3632, V3668, V3714, UMNH VP 30185, 30186, 30208, 30209, 30210, 30217, 156046, 165214, 175068, 175073, 175082, 175084, 175085, 175093, 175100, 175101-175103, 175105, 175101-175103, 175105, 175121, 175132, 175133, 175138, 195236, 195240, 195248, 285847, 285848, 285865, 285867, 285868, 285872, 285878, 285888, 285889, 285901, 285905, 30185, 30186, 30208, 30209, 30210, 30217: Paramedian osteoderms.

PEFO 31781, 37245, 38744, 38774, 40741, 4451, 44453, 44454, 44456, MNA V3046, V3631, UMNH VP 30184, UCMP 139577-139581, 139583, 139589-139601, 139603-13609, 139611, 139613, 139614-139619, 139621, 156046, 175096, 175106-175108, 175110, 175113-175120, 175123-175126, 195232, 195233, 195234, 195235, 195237, 195238, 195243-195247, 295831, 285849, 285855, 285857, 285863, 285871, 285874, 285877, 285887, 285934: Lateral osteoderms.

UCMP 139602, 139610, 139620, 175060, 175069, 175074, 17581, 175097, 175134, 175135, 175139, 195241, 2858259, 285834, 285861, 285879, 285881, 285883, 285864: Venteral osteoderms.

UCMP PEFO 20358, 31717, 37173, 37181, 37233, 37245, 37323, 37326, 38264, 38738, 38761, 40692, 40701, 40713, 40721, 40722, 40732, 40734, 40736, 40744, 40747, 40748, 40749, 40750, 40751, MNA V2921, V2952, V3002, V3007, V3050, V3679, UCMP 139613, 175071, 175122, 175127-175129, 175141, 175155, 195239, 195242, 285839, 285845, 285846, 285850, 285852, 285853, 285859, 285860, 285863, 285873, 285876, 285883-285886, 285890-285893, 285899, 285902, 285907, 285908, 285910, 139586 (139584 label), 139486 (1398585 label), 139586 (139586 label), 175130 (175130 label), 175130, (175131 label), UCM 76194: Partial osteoderms.

Locality: Placerias quarry (UCMP A269, MNA 207C), Big Hollow Wash near Romero Springs, a small valley 6 1/2 miles (approximately 10.4 km) S 65"W of St. Johns, Apache County, Arizona.
Note: 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:

MNA V3668, MNA Pl.3040, 3043: Paramedian plates.

MNA V3679: 6 plates.

MNA Pl. 2921: 4 plates.

MNA Pl.2952: Plate.

MNA Pl. 3002: 8 fragments of plates.

MNA Pl.3007: 2 fragments of plates.

MNA Pl. 3046: Plate.

PEFO 43699: Maxilla.

PEFO 44457, UCMP 285854: Frontal.

UCMP 285909: Parietal.

UCMP 285837: Squamosal.

MNA V3679, UCMP 293853: Articular and surangula.

 

Locality: Downs Quarry (MNA Loc. 207N), approximately 72 m east of Placerias Quarry, Big Hollow Wash near Romero Spring, approximately 10.4 km southwest of St. Johns, Apache County, Arizona.

Horizon: Bluewater Creek Formation, Lower Chinle Group.

Biostratigraphy:

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

Material:

MNA V3714, MNA Pl. 3066: Parameidan plates.

MNA Pl. 3050: 2 plates.

MNA Pl. 3067, 3113: Plates.

 

Locality: Rincon Basin E (UCMP), 16 km northeast of Winslow on eastern margin of Rincon Basin, Winslow Area, Petrified Forest, Navajo County, Arizona.

Horizon: Lower Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material:

UCMP: Paramedian plate.

HUNT, OLSON, HUBER, SHIPMAN, BIRCHEFF & FROST, 1996

Locality: Dinosaur Ridge, Petrified Forest National Park, Apache County, Arizona.

Horizon: Blue Mesa Member, Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material:

Number: Not given: Several Osteoderms.

 

MARSH, PARKER, NESBITT, KLIGMAN & STOCKER, 2022

Locality: Dinosaur Wash (PFV 217, Field numbers WGP 14/24, ADM 15'17, ADM 15'18, ADM 15/24-15/32, ADM 15/34, aDM 15/35), Petrified Forest Natinoal Park, Apache County, Arizona.

Horizon: Upper part of the Blue Mesa Member, Chinle Formation.

Biostratigraphy:

Age: Norian Stage, Late Traissic Epoch, Late Triassic.

Material:

PEFO 44219: Osteoderm.

 

POLCYN, WINKLER, JACOS & NEWMAN, 2002

Locality: SMU locality 252, vicinity of North Stinking Springs Mountian, what use to be Seven Springs Ranch, northwest of St. Johns, Apache County, Arizona.

Horizon: Lowe Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material:

Number: Not given: