Species: rex OSBORN, 1905
Etymology: Greek, rex, the king: “Tyrant lizard, the King”.
Holotype: CM 9380 (Formerly AMNH 973)
Locality: Quarry 1, near Jordan, Garfield County, Montana.
Horizon: Hell Creek Formation, 220 feet above the Bearpaw Shale.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material: Partial skull and mandible, right? ectopterygoid missidentified as a right postorbital, one cervical, seven dorsals, five sacrals, three abdominal ribs, right scapula, left humerus, ilia, pubes, ischia, left femur and part of right, tibia, right metatarsals II, and III, left metatarsal IV of a robust individual.
Note: Has erosive lesions, probably from Trichomonas gallinae-like protozoan on the dentary (WOLFF, SALISBURY, HORNER & VARRICCHIO, 2009). Lesion description: Round, tapered edge, rim remodelling.
Note: Also has evidence of face bitting (WOLFF, SALISBURY, HORNER & VARRICCHIO, 2009).
Referred material:
Locality: Near Jordan, Dawson County, Montana.
Horizon: Lance Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Referred material:
AMNH 5027: Skull and jaws, cervical, dorsal, and most of caudal vertebrae, ribs, cervical ribs, ilium, pubis and ischium of a more gracile individual.
Note: Paleopathologies, dorsals 7 and 8 exhibit pathological fusion of the centra (NEWMAN, 1970, the centra of cervical 10 and dorsal 1 are also fused (ROTHSCHILD, 1997). Nasal claw groove on the nasal, and the post-orbital has a large hole, made by a pes claw (ROTHSCHILD, 2013).CM 9379 (Formerly AMNH 5029): Occiput and Brain case, sectioned.
Note: Has erosive lesions, probably from Trichomonas gallinae-like protozoan on the dentary (WOLFF, SALISBURY, HORNER & VARRICCHIO, 2009). Lesion description: Round rectangle, tapered edge, remodelled.
Locality: On the Lester D. Engdahl Ranch (not, as originally noted, the F. S. McKeever Ranch), S34, T21N, R37E, near Jordan, Garfield County, Montana.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
LACM 23844: Disarticulated skull and fragmentary skeleton.
Note: Pathological openings in the right surangulars.Note: Stress fracture on a proximal phalanx (ROTHSCHILD & TANKE, 2005).
Locality: T-rex skull site, Near Custer, Gairfield County, Montana.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
MOR 008: Skull missing only the left premaxilla, the right palatine, the right epiptergoid, and the vomer, the lower jaw is missing the splineals, the coronoics, the right dentary, and left prearticular, and has the atlas.
Note: Palaeopathologies, pathological openings in the right surangulars, the squamosal articular surface of the right quadrate is rugose and partly hemispherical in form (MOLNAR, 2001). The dentary has a hole possibly made by a pedal ungual (ROTHSCHILDS, 2013).
BURNHAM, ROTHSCHILD & NUDDS, 2022
Locality: Whitney Ranch, Niobrara County, Woming.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
AWMM-IL 2022.9: Left angular, left postorbital, right squamosal, prearticular, right ilium, right ischium, caudal vertebra 1-7, dorsal vertebra 1-14, Haemal arch, 3, 5, left dorsal rib 4, 9, 8, left femur, left shaft and proximal end of left fibula, left ischium, left metatarsals 3, 4, left pubis, left scapula, left tibia, right tibia, right astragalus, right dorsal rib 5, 6, right femur, right fibula, right metatarsal 3, 4, right pubis sacral vertebra 1, 2, 5, right metatarsal 1, left metatarsal 1, left metatarsal 2, right dorsal rib 4, rib head and section of iliac blade.
Note: Paleopathology on the articualr surfaces of the ischium, femur and the astragalus has 2 lesions on the ascending process.
LARSON, 2008
Locality: Don and Allison Wyrick Ranch, north of Baker, Fallon County, Montana.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, lower Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
BHI 6230 (Wyrex): Partial braincase, right squamosal, postorbital, jugal, surangular, articular, prearticular, angular, 2 nearly complete legs adn feet (lacking to date [2008] the left tibia, astragalus, calcanieum, 1 left tarsal, both metatarsal 1, and 5 pes phalanges from the right foot), 5 dorsal, 1 cervical, 11 caudal vertebrae, 5 cervical, 15 dorsal ribs, both ischia, right pubis, right ilium, left scapula, coracoid, humerus, ulna, carpals, all 3 metacarpals, and 17 gastralia.
Note: Skin impression.
Note: Possible manual claw hole on the jugal (ROTSHSCHILD, 2013).
Locality: Donald Zimmershied Ranch, near the Jump-off, Harding County, South Dakota.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
Samson (Z-rex, Mr. Z., Mr. Zed): Nearly complete skull, 9 cervical and 7 dorsal vertebrae, 2 cervical and 10 dorsal ribs, 17 caudals, at least 4 chevrons, both femora, left fibula, abundant tibia pieces, 3 metatarsals, and 20 pes phalanges.
Note: A large portion of the left lacrimal has been ripped away, exposing the underlying sinus,and a large surangualr defect, possible made by a pedal claw (ROTHSCHILDS, 2013).
LARSON, P., & FREY, 1992, LARSON, N., 2008
Locality: Jon, Betty, and David Niemi Ranch, near Buffalo, Harding County, South Dakota.
Horizon: Hell Creek Formation, 16 m beneath the K-T boundary.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
BHI 3033 (Stan): Nearly complete skull missing only the right articular and left coronid, both dentaries, 9 cervical, 14 dorsal, 5 sacral, 31 caudal vertebrae, 24 chevrons, 14 cervical ribs including the proatlas, 12 dorsal ribs, a nearly complete pelvic girdle (the distal ends of both ischia and pubes were weathered away), left femora, both tibiae, left fibula, both calcanea and astragali, 2 left metatarsals and 11 pes phalanges.
Note: This is a gracile animal (Male).
Note: Broken ribs, ankylosed cervicals, bitten and broken parietal, anomoalous opeings in the right jugal and surangular (MOLNAR, 2001), tooth marks? holes, on the jugal and surangular (also possible made by manual claws) (ROTHSCHILDS, 2013).
LARSON & RIGBY, 2005
Locality: On the ranch of Wade and Loren Derflinger, Perkins County, South Dakota.
Horizon: Hell Creek Formation, not far from above the contact of the Fox Hills Formation..
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
TCM (CMI) 2001.90.1 (Bucky, formerly BHI 2960): 8 cervical, 9 dorsal, 5 sacral, 15 caudal vertebrae, 14 chevrons, 11 cervical ribs, 16 dorsal ribs, 24 gastralia, a complete furcula, scapulae, right coracoid, left ulna, 2 manus phalanges, ilia, ischia, 4 metatarsals, and 9 pes phalanges.
Note: Furcula is pathologic (LARSON, N., 2008).
Locality: East of Fort Peck Lake, McCone County, Montana.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
MOR 980 (Rigby Rex, Peck's Rex): Braincase, both maxillae, both premaxillae, incomplete nasals (most of the right), right postorital, right jugal, both lacrimals, both quadrates, both quadratojugals, both dentaires, left splenial, left prearticular, right surangular, right angular, furcula, both scapulae, 1 coracoid, both humeri, metacarpal III, 3 manus phalanges, right leg with calcaneum, astragalus, 1 metatarsal, left ilium, partial right ilium, both pubes, both ischia, sacral vertebrae, some dorsal and cervical vertebrae, a string of 9 or 10 anterior caudal vertebrae most with chevrons, many dorsal ribs, some cervical ribs and a few gastralia.
Note: Possible pes ungual hole in the lower jaw (surangular) (ROTHSCHILDS, 2013).
LOEWEN, SAMPSON, GETTY & DIFLEY, 2001, DIFLEY & EKDALE, 2002, SAMPSON & LOWEN, 2005
Locality: Central Utah.
Horizon: North Horn Formation.
Biostratigraphy: Unit 1B
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
UMNH 11000: Nearly complete right postorbital and squamoal, cervical vertebrae 3, 4, sacral vertebrae 2, 3, 4, and a series of mid-caudal vertebrae perhaps 10-16, chevrons cranial to each ca6, 13-17, along with a single mid-dorsal rib, distal blade of right ilium, left pubic peduncle, proximal end of left ischium, left tibia, fibula and astragalus.
Note: Palopathologies on the fibula and 4 other unidentified elements.
STEIN, 2021
Locality: Tooth Draw Deposit, Butte County, South Dakota.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
PARC-TD-11-094/FDM-xx?: Left dentary.
Note: With bite marks and/or infection with rasied scar tissue on its lower anterior end and another cluster of pathologic inguries with raisd scar tissue found in a line at the caudal end.
= Tyrannosaurus stanwimstonorum PICKERING in prep
Note: Also SDSMT 12047Locality: Near Faith, Hill City, South Dakota.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
FMNH PR2081 (was Black Hills Institute of Geological Research.(Sue) 2033): Skull and skeleton. With pathologies, 2 broken fibula, broken ribs with a tyrannosaur tooth in one, 2 broken caudal vertebrae, injured lower jaw with malformed double cusped tooth, and the top of the skull with tooth marks across it.
Note: Pathologies are healed osteomylitis (infection) of the left fibula, healded proximal humerus, exuberant vertebral osteophyte formation, and multiple bilaterally-present erosive lesions primarily confined to the post-dentary mandibular elements. No evidence of pre or peri-mortem bite marks (REGA, 2001, BROCHU, (2002) 2003). Furcula is also pathologic (LARSON & RIGBY, 2005).
2 broken fibula, broken ribs with a tyrannosaur tooth in one, 2 broken caudal vertebrae, injured lower jaw with malformed double cusped tooth (LARSON & RIGBY, 2005, HAMM, HAMPE, SCHWARZ, WITZMANN, MAKOVICKY, BROCHU, REITER & ASBACH, 2020).Note: Has erosive lesions, probably from Trichomonas gallinae-like protozoan on the dentary (WOLFF, SALISBURY, HORNER & VARRICCHIO, 2009) and on some of its theeth (BRINK, 2019). Lesion description: Round, tapered edge, rim thickening/remodelling, infrequent median process.
Locality: East of Fort Peck Lake, McCone County, Montana.
Horizon: Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
MOR 980 (Rigby Rex, Peck's Rex): Braincase, both maxillae, both premaxillae, incomplete nasals (most of the right), right postorital, right jugal, both lacrimals, both quadrates, both quadratojugals, both dentaires, left splenial, left prearticular, right surangular, right angular, furcula, both scapulae, 1 coracoid, both humeri, metacarpal III, 3 manus phalanges, right leg with calcaneum, astragalus, 1 metatarsal, left ilium, partial right ilium, both pubes, both ischia, sacral vertebrae, some dorsal and cervical vertebrae, a string of 9 or 10 anterior caudal vertebrae most with chevrons, many dorsal ribs, some cervical ribs and a few gastralia.
Note: Furcula.
Note: Nicknamed "Peck's rex".
Note: Has erosive lesions, probably from Trichomonas gallinae-like protozoan on the dentary (WOLFF, SALISBURY, HORNER & VARRICCHIO, 2009). Lesion description: Round, to sub-oval, tapered edge, rim remodelling, minor lesions on opposite side.
SCHWEITZER, WITTMEYER & HORNER, 2005, LARSON, N., 2008
Locality: Near Fort Peck Lake, Charles M. Russell National Wildlife Refuge, Garfield County, Montana.
Horizon: Base of the Hell Creek Formation.
Biostratigraphy:
Age: Lancian age, lower Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
MOR 1125 (Bob, B-rex): Both premaxilla, dentary, plus a few other skull bones, 3 cervical, 4 dorsal, 5 sacral, 12 caudal vertebrae, 7 chevrons, 4 cervical, 13 dorsal ribs, left scapula, left coracoid, furcula, left ulna, both femora, tibiae, fibulae, right calcaneum, right astragalus, and 11 pes phalanges.
Note: Soft tissue from the marrow of a left femur shows it is a female (SCHWEITZER, WITTMEYER & HORNER, 2005).Note: Has skin impressions around the femur (SCHWEITZER, WITTMEYER & HORNER, 2004).
Note: Has erosive lesions, probably from Trichomonas gallinae-like protozoan on the dentary (WOLFF, SALISBURY, HORNER & VARRICCHIO, 2009) . Lesion description: Round, tapered edge, rim remodelled.
WOLBERG, LONZINSKY & HUNT, 1986, WILLIAMSON & CARR, 2005Locality: NMMNH Locality 353, Staton-LaPoint locality, 1.1 km north of Kettle Top Butte on the eastern shore of Elephant Butte Reservoir, New Mexico.
Horizon: Hall Lake Member, McRae Formation.
Biostratigraphy:
Age: Lancian age, upper Maastrichtian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.
Material:
NMMNH P-3698 (old NMMNH P-1013-1): Left dentary, right palatine (misidentified as an incomplete articular), a right prearticular, right squamosal, right postorbital, splenial, incomplete teeth, and one nearly complete chevron.
Note: The dentary has a hole possibly made by the manus claw (ROTHSCHILDS, 2013).