Genus: Hesperosuchus COLBERT, 1952
Etymology: Greek, hesper, "western" and Greek, souchos, "crocodile."

Species: agilis COLBERT, 1952
Etymology: Latin, agilis, "agile."

Holotype: AMNH 6758

Locality: On the north side of the Little Colorado River, near Tanner Crossing, about 6 miles (9.5 km) southeast of Cameron, Coconino County, Arizona.

Horizon: Lower part of the Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material: Fronto-parietal region of the cranial roof, much of the occiput, other skull fragments, posterior fragment of right maxilla, left premaxilla and maxilla, right quadrate, portion of an articular(?), a large portion of the left mandibular ramus, the first 10 presacral vertebrae not definitely identifiable as to position, sacral vertebra, various fragments of vertebrae, various cervical and thoracic ribs, left scapula and proximal portion of coracoid, left humerus, right humerus, left radius and ulna, proximal portions of metacarpals of right manus, left femur, a greater part of the left tibia, portion of left fibula, portions of right femur, proximal end of right fibula, 3 metatarsals, various phalanges, numerous fragments of foot bones and limb bones, and several dorsal scutes.

Hesperosuchus agilis (modified from Colbert, 1952).

 

Referred material:

CLARK, SUES & BERMAN, 2000

Locality: Ghost Ranch Quarry or the Whitaker Quarry, SE 1/4, SE. 1/4, SW 1/4, Section 1, Township 24 North, Range 4 East, Rio Arriba County, New Mexico.

Horizon: Rock Point Formation, Chinle Group.

Biostratigraphy:

Age: Apachean, Late Norian Stage, Upper Late Triassic Epoch, Late Late Triassic.

Material:

CM 29894: Skull and articulated partial postcranial skeleton.

RINEHART, LUCAS, HECKERT, SPIELMANN & CELESKEY, 2009

NMMNH P-41600: Tooth.

NMMNH P-57654: 5 rhombic to retrangula osteoderms.

 

HUNT & LUCAS, 1989

Locality: Barranca Creek, Secs. 6-7, T 10N, R33 E: secs. 1-2, T10N, R32E; sec. 31, T11N, R33E, ownership is private and State of New Mexico.

Horizon: Bull Canyon Formation.

Biostratigraphy:

Age: Revueltian, Early Norian Substage, Early Norian Epoch, Middle Late Triassic Epoch, Late Triassic.

Material:

Number: Not given: Vertebrae, pelvic fragments and a jaw fragment.

 


Locality: Revuelto Creek, Secs. 9-10, 14-16 and 21-22, T10N, R33E, Quay County, New Mexico.

Horizon: Bull Canyon Formation.

Biostratigraphy:

Age: Revueltian, Early Norian Substage, Early Norian Epoch, Middle Late Triassic Epoch, Late Triassic.

Material:

Number: Not given: 2 post skeletons and postcranina.

 


HUNT & LUCAS, 1995

Locality: NMMNH locality 149, NW 1/4, SW 1/4, SE 1/4, sec. 2, T14N, R10E, Santa Fe County, New Mexico.

Horizon: Los Esteros Member, Santa Rosa Formation.

Biostratigraphy:

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

Material:

Number: Not given: A few vertebrae.

 

MURRY & LONG, 1989

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.

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. (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:

Number: Not given:

 


LONG & MURRY, 1995

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: Lower Petrified Forest Formation, Chinle Group.

Biostratigraphy:

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

Material:

MNA Pl. 3102: Radius.

 


Locality: West side of White River crossing of old Spur-Crosbyton Road, Crosby County, Texas.

Horizon: Tecovas Formation, Dockum Group.

Biostratigraphy:

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

Material:

UMMP 10604: Much of postcranial skeleton.
(CASE, 1929, p. 52-54, figs. 24a-c, left calcaneum figured, but caption reversed with fig. 23).

 

= cf. Sphenosuchus sp PARRISH, 1991

Locality: Lacey Point quarry, (Dinosaur Hill of LONG & MURRY, 1995), UCMP locality V82250, "Painted Desert", Petrified Forest, Arizona.

Horizon: Upper Unit of the Petrified Forest Formation, Upper Chinle Group.

Biostratigraphy:

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

Material:

UCMP 129470: Fragmentary lower jaw, and fragmentary skeleton.

 

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: