Genus:

Etymology: Greek,

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Species: *peeblesorum* HORNER & MAKELA, 1979

Etymology: In honor of the James and John Peebles families, owners of the land
where the specimens were collected.

Holotype: YPM 22405

Locality: 12 miles west of Choteau, on the James and John Peebles Ranch, Willow Creek Anticline, Teton County, Montana.

Horizon: Two Medicine Formation.

Note: Equivalent to the Lower to Middle Dinosaur Park Formation

Biostratigraphy:

Age: Judithian age, Campanian Stage, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.

Material: Skull with partial right dentary and predentary.

Top two After Horner; Bottom after a ROM specimen.

Referred material:

YPM 22400: skeletons of 15 individuals, of babes, juveniles and adults.

Numerous eggs, eggshells, and nests.

Referred material:

HORNER, 1988

Material:

Lower

Maiasauranesting Ground.

Maiasaurabonebed.Upper

Maiasauranesting Ground.HORNER, 1999

MOR 244: Embryonic remains, Mid-shaft of a femur, proximal end of a tibia, 2 caudal vertebrae, partial dentary battery, partial parietal, cervical centrum, dorsal centrum, caudal centrum, partial humerus, distal metatarsal III, distal tibia, and partial right scapula.

MOR 281: 16 eggs in a nest.

Note: Incorrectly listed as MOR 328 by HIRSCH & QUINN, 1990.HORNER, 1992

MOR 005, MOR 547:

HORNER, 1994

MOR 236: Partial skeleton.

HORNER, RICQLES & PADIAN, 2000

YPM 33472: Early juvenile.

MOR 005JV: Late Juvenile.

MOR 0055A: Subadult.

MOR 005A: Adult.

HORNER & WEISHAMPEL, 1988

PU 22432: Embryonic remains in an egg.

PRIETO-MARQUEZ & GUENTHER, 2018

YPM-PU 22400: 6 left and 8 right maxillae (as well as 3 maxillary fragments), 2 partial left quadrates, 2 right jugals, 12 left and 12 right dentaries (as well as dentary fragments), a partial left sternal plate, a right coracoid, partial left and right scapulae, 6 left and 6 right humeri, 2 right and 2 left ulnae, 2 right and 1 left radii, left manus, right manual digits II, III and IV, a nearly complete right ilium missing the postacetabular process, the central plate of a right ilium, the preacetabular processes of a left and right ilia, 1 right and 2 left proximal ischiadic fragments, a left pubis, 24 femora, 16 tibiae, a partial left and 3 right fibulae, a left and right astragalus, a left calcaneum, a right metatarsal II, 2 left and 1 right metatarsal III, a right metatarsal IV, an articulated left and right pes, a pedal phalanx III-1 and various other indeterminate postcranial fragments.

STEIN, 2001

Pathological neural spine (a neural arch with 3 spines).

GATES, HORNER, HANA & NELSON, 2011

TCMI 2001.89.2

TREXLER, 1994

Locality: Montana.

Horizon: Two Medicine Formation.

Note: Equivalent to the Lower to Middle Dinosaur Park FormationBiostratigraphy:

Age: Judithian age, Campanian Stage, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.

Material:

ROM 44770: An adult skull and skeleton.

Note: This specimen shows its more closely related toBrachylophosaurus.

Note: With skin impressions (BELL, 2014).