Species: mjosi CARPENTER, MILES & CLOWARD, 2001
Etymology: In honor of Ronald G. Mjos (‘mus’), who was responsible for collecting and preparing the specimen and for mounting a cast of the holotype skeleton.
= Stegosaurus mjosi (CARPENTER, MILES & CLOWARD, 2001) MAIDMENT, NORMAN, BARRETT & UPCHURCH, 2008

Holotype: HMNS 14 (old HMNS 001)

Locality: S. B. Smith Ranch, Johnson County, Wyoming.

Horizon: 5 meters above the base of the Morrison Formation, Lower Salt Water Wash Member, Morrison Formation.

Biostratigraphy: Zone 1.

Age: Lower Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.

Material: A nearly complete disarticulated skull, 1 hyoid, 13 cervicals, 13 dorsals, 44 caudals, most of the cervical and dorsal ribs, most of the chevrons, 10 dermal plates, both ilia, both ischia and both pubes, partial left scapula, and ossified tendons.

DMNH 29421: Cast.

Referred material:

CHRISTIANSEN & TSCHOPP, 2010

Locality: Howe-Stephens Quarry, 44°39'N, 107°49'W, 450 m southwest of the historic Howe Quarry, near Shell, Greybull, Big Horn County, Wyoming.

Horizon: Member? Morrison Formation.

Biostratigraphy: Zone?

Age: Age?, Stage?, Malm Epoch, Late Jurassic.

Material:

SMA 0018 (old SMA V03): Fragmentary skull and skeleton.

Note: With skin impressions.

SIBER & MÖCKLI, 2009

Saurier Museum, "Victoria": Nearly complete skull and skeleton.

SAITTA, 2015

SMA 0092 (old SMA L02), VFSMA 001 (old SMA 3074-FV01, SMA M04:

 

Locality: JRDI 5ES Quarry, near Grass Range, Montana.

Horizon: Member? Morrison Formation.

Biostratigraphy: Zone?

Age: Age?, Stage?, Malm Epoch, Late Jurassic.

Material:

Numbers: Not given: 5 specimens.

 

Localtiy: Meilyn Quarry, Como Bluff, Wyoming.

Horizon: Member? Morrison Formation.

Biostratigraphy: Zone?

Age: Age?, Stage?, Malm Epoch, Late Jurassic.

Material:

Numbers: Not given: 2 specimens.

 

FULLER, 2009

Locality: Dana Quarry, Ten Sleep, Washakie County, Wyoming.

Horizon: Member?, Morrison Formation.

Biostratigraphy: Zone?

Age: Age? Stage?, Malm Epoch, Late Jurassic.

Material:

Number: Not given: Skeletal remains.

 

MAIDMENT, WOODRUFF & HORNER, 2018

Locality: MOR's O'Hair Quarry (formelry Strickland Creek Quarry), Park County, Montana.

Locality: Dana Quarry, Ten Sleep, Washakie County, Wyoming.

Horizon: Member?, Morrison Formation.

Biostratigraphy: Zone?

Age: Age? Stage?, Malm Epoch, Late Jurassic.

Material:

MOR 9728: A nearly complete skull, 8 cervical vertebrae, 1 dorsal, and 2 sacral vertebrae, right scapulocoracoid, parts of left element, both humeri, right tibia, fibula, astragalus and calcneum, a metatarsal and a partial dermal plate.

 

= cf. Hesperosaurus mjosi SIBER & MÖCKLI, 2009

Locality: Howe-Scott Quarry, southwest of the historic Howe Quarry and north-east of the Howe-Stephens Quarry, near Shell, Greybull, Big Horn County, Wyoming.

Horizon: Member? Morrison Formation.

Biostratigraphy: Zone?

Age: Age?, Stage?, Malm Epoch, Late Jurassic.

Material:

Saurier Museum, "Moritz"; Fragmentary skull and fragmentary skeleton.

Saurier Museum, "Lilly": nearly complete skull and skeleton.