# Kirtland Formation

The Kirtland Formation (originally the Kirtland Shale) is a sedimentary geological formation.

## Description

The Kirtland Formation is the product of alluvial muds and overbank sand deposits from the many channels draining the coastal plain that existed on the inland seashore of North America, in the late Cretaceous period. It overlies the Fruitland Formation. It is found in the San Juan Basin in the states of New Mexico and Colorado, in the United States of America.
The base of the Kirtland Formation and its lowest sub-unit, the Hunter Wash member, has been dated to 75.02 ± 0.13 Ma. Together with the upper part of the underlying Fruitland Formation, this contains fossils representing the Hunter Wash local fauna. The border between the Hunter Wash member and overlying Farmington member dates to approximately 74 million years ago. The top of the Farmington member and bottom of the overlying De-na-zin member has been radiometrically dated to 73.83 ± 0.18 Ma ago. The top of the De-na-zin member, which contains the Willow Wash local fauna, has been dated to 73.49 ± 0.25 Ma ago.
Overlying the De-na-zin member is a unit called the Naashoibito member This has often been considered to be part of the Kirtland formation, but more recently has been transferred back to the overlying Ojo Alamo Formation, which it had originally been part of.

## History of investigation

The formation was named by C.M. Bauer in 1916 for exposures near the Kirtland Post Office.

## Vertebrate paleofauna
### Saurischians

| Saurischians of the Kirtland Formation | Saurischians of the Kirtland Formation | Saurischians of the Kirtland Formation | Saurischians of the Kirtland Formation | Saurischians of the Kirtland Formation | Saurischians of the Kirtland Formation |
| Genus | Species | Member | Material | Notes | Images |
| Alamosaurus | A. sanjuanensis | | | Specimens actually from the Naashoibito member of the Ojo Alamo Formation | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Aublysodon | A. mirandus | Hunter Wash | | Remains are now referred to Bistahieversor, although these remains may possibly have come from the Fruitland Formation. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Bistahieversor | B. sealeyi | Hunter Wash | An articulated skull and undescribed postcranial skeleton of an adult individual, and an incomplete skull and postcranial skeleton of a juvenile individual. | A eutyrannosaur tyrannosauroid also known from the Fruitland Formation. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Caenagnathidae | Indeterminate | De-na-zin | A nearly complete right tibia | Indeterminate caenagnathid remains. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Daspletosaurus | Indeterminate | Hunter Wash | | Remains are now referred to Bistahieversor, although these remains may possibly have come from the Fruitland Formation. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Dromaeosauridae | Indeterminate | | Numerous isolated teeth. | Indeterminate dromaeosaurid remains. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Ornithomimidae | Indeterminate | De-na-zin | A distal end of a phalanx, and [two] partial manual unguals. | Indeterminate ornithomimid remains. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Saurornitholestes | S. sullivani | De-na-zin | A nearly complete frontal. | A saurornitholestine dromaeosaurid, sister taxa to Saurornitholestes langstoni. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| "Saurornitholestes" | "S." robustus | De-na-zin | A nearly complete frontal. | Originally assigned to Saurornitholestes, actually a troodontid. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| cf. Struthiomimus | cf. S. altus | | A centrum of a dorsal vertebra, distal portion of a metatarsal, and proximal phalanx. | Indeterminate remains that may belong to Struthiomimus altus. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |
| Tyrannosauridae | Indeterminate | | A partial skeleton, dentary, metatarsal, and numerous teeth. | Indeterminate tyrannosaurid material. | Alamosaurus Bistahieversor Saurornitholestes Struthiomimus |

### Ornithischians

Ornithischians reported from the Kirtland Formation :
| Genus | Species | Member | Material | Notes | Images |
| Ahshislepelta | A. minor | Hunter Wash | A partial girdle, scapulocoracoids, humerus, proximal portion of the radius, cervical and/or dorsal vertebrae, complete and fragmentary thoracic osteoderms, and other unidentifiable postcranial fragments. | An ankylosaurine ankylosaurid part of the Hunter Wash Member. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Anasazisaurus | A. horneri | De-Na-Zin | An incomplete skull consisting of premaxillae, nasals, maxilla, lacrimal, jugal, prefrontal, postorbital, squamosal, frontal, parietal, and fragment of dentary with teeth. | A kritosaurin hadrosaurid from the De-Na-Zin Member. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Bisticeratops | B. froeseorum | Farmington | A nearly complete skull. | A chasmosaurine ceratopsid, originally identified as a specimen of Pentaceratops. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Kritosaurus | K. navajovius | De-na-zin | [Two] incomplete skulls, an atlas, axis and cervical vertebrae. | A kritosaurin hadrosaurid also known from the Cerro del Pueblo Formation of Mexico. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Naashoibitosaurus | N.ostromi | De-na-zin | A skull lacking the premaxillae and mandible, a partial humerus, cervical vertebrae and dorsal vertebrae. | A kritosaurin hadrosaurid, distinct from Kritosaurus. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Nodocephalosaurus | N. kirtlandensis | De-na-zin | A partial skull. | An ankylosaurine ankylosaurid that has cranial ornamentation similar to Akainacephalus, an ankylosaur from the Kaiparowits Formation. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Parasaurolophus | P. tubicen | De-na-zin | [Two] incomplete and fragmentary skulls. | A lambeosaurine hadrosaurid known from partial cranial remains. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Pentaceratops | P. fenestratus | De-na-zin Member | A crushed but nearly complete skull, mandible, cervical vertebrae, dorsal vertebrae, sacral vertebrae, caudal vertebrae, chevrons, scapulae, coracoids, radii, ulnae, ischia, ilia, pubes, femora, tibiae, astragali, manual phalanxes and manual unguals. | A junior synonym of Pentaceratops sternbergii, diagnostic characteristics of the species were pathologies. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Pentaceratops | P. sternbergi | De-na-zin | A crushed but nearly complete skull, mandible, cervical vertebrae, dorsal vertebrae, sacral vertebrae, caudal vertebrae, chevrons, scapulae, coracoids, radii, ulnae, ischia, ilia, pubes, femora, tibiae, astragali, manual phalanxes and manual unguals. | A chasmosaurine ceratopsid also known from the Fruitland Formation. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Sphaerotholus | S. goodwini | De-na-zin | A partial skull lacking the facial and palatal elements. | A pachycephalosaurine pachycephalosaurid also known from the Hell Creek and Horseshoe Canyon Formation. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Stegoceras | S. novomexicanum | Hunter Wash | An incomplete parietal. | A basal pachycephalosaurid also known from the upper Fruitland Formation. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Terminocavus | T. sealeyi | Hunter Wash | A parietal, partial squamosal, jugal, epijugal, partial quadratojugal, partial sacrum and vertebral fragments. | A chasmosaurine ceratopsid that has been hypothesized to form an anagenetic series with several other chasmosaur species, including Navajoceratops. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Navajoceratops | N. sullivani | Hunter Wash | A parietal, squamosal fragments, fused jugal\epijugal and other unidentified cranial fragments. | A chasmosaurine ceratopsid that has been hypothesized to form an anagenetic series with several other chasmosaur species, including Terminocavus. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Titanoceratops | T. ouranos | | A partial skull, syncervical vertebrae, cervical vertebrae, dorsal vertebrae, sacral vertebrae, caudal vertebrae, ribs, humeri, radius, femora, tibiae, fibula, ilia, ischia, and ossified tendons. | Possibly represents a junior synonym of Pentaceratops, holotype may possibly have come from the Fruitland Formation. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |
| Ziapelta | Z. sanjuanensis | Hunter Wash De-na-zin | A complete skull, [two] first cervical half-rings, fragmentary second cervical half ring, and numerous fragmentary osteoderms. | An ankylosaurine ankylosaurid closely related to Scolosaurus. | Bisticeratops Kritosaurus Naashoibitosaurus Nodocephalosaurus (right) Pentaceratops Sphaerotholus Stegoceras Terminocavus Navajoceratops Titanoceratops Ziapelta |

### Pterosaurs

| Pterosaurs of the Kirtland Formation | Pterosaurs of the Kirtland Formation | Pterosaurs of the Kirtland Formation | Pterosaurs of the Kirtland Formation | Pterosaurs of the Kirtland Formation | Pterosaurs of the Kirtland Formation | |
| Genus | Species | Location | Member | Abundance | Notes | Images |
| Navajodactylus | N. boerei | | Hunter Wash Member | Partial phalanx and ulna fragment | A possible azhdarchid pterosaur known from fragmentary remains. | |

### Crurotarsans

Crurotarsans of the Kirtland Formation :
| Genus | Species | Member | Notes |
| Brachychampsa | B. montana | De-na-zin | Member of the Willow Wash local fauna. |
| Denazinosuchus | D. kirtlandicus | De-na-zin | Member of the Willow Wash local fauna. |
| Leidyosuchus | Indeterminate | De-na-zin | Member of the Willow Wash local fauna. |

### Turtles

| Turtles of the Kirtland Formation | Turtles of the Kirtland Formation | Turtles of the Kirtland Formation | Turtles of the Kirtland Formation | Turtles of the Kirtland Formation | Turtles of the Kirtland Formation | |
| Genus | Species | Location | Member | Abundance | Notes | Images |
| Basilemys | B. nobilis | | De-na-zin | | Member of the Willow Wash local fauna. | |
| Denazinemys | D. nodosa | | De-na-zin | | Member of the Willow Wash local fauna. | |
| Neurankylus | N. baueri | | De-na-zin | | Member of the Willow Wash local fauna. | |
| Plastomenus | P. robustus | | De-na-zin | | Member of the Willow Wash local fauna. | |
| Thescelus | T. hemispherica | | De-na-zin | | Member of the Willow Wash local fauna. | |

### Bony fish

Bony fishes of the Kirtland Formation :
| Genus | Species | Location | Member | Abundance | Notes |
| Melvius | M. chauliodous | | De-na-zin | | Member of the Willow Wash local fauna. |

### Cartilaginous fish

Cartilaginous fish of the Kirtland Formation :
| Genus | Species | Location | Member | Abundance | Notes |
| Myledaphus | M. bipartitus | | De-na-zin | | Member of the Willow Wash local fauna. |
| Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |