# Kayenta Formation

The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau area of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Originally suggested as being Sinemurian-Pliensbachian, but more recent dating of detrital zircons has yielded a depositional age of 183.7 ± 2.7 Ma, thus a Pliensbachian-Toarcian age is more likely. A previous depth work recovered a solid "Carixian" (Lower-Middle Pliensbachian) age from measurements done in the Tenney Canyon. More recent works have provided varied datations for the layers, with samples from Colorado and Arizona suggesting 197.0±1.5-195.2±5.5 Ma (Middle Sinemurian), while the topmost section is likely Toarcian or close in age, maybe even recovering terrestrial deposits coeval with the Toarcian Oceanic Anoxic Event. This last age asignation also correlated the Toarcian Vulcanism on the west Cordilleran Magmatic Arc, as the number of grains from this event correlate with the silt content in the sandstones of the upper layers.
This rock formation is particularly prominent in southeastern Utah, where it is seen in the main attractions of a number of national parks and monuments. These include Zion National Park, Capitol Reef National Park, the San Rafael Swell, and Canyonlands National Park.
The Kayenta Formation frequently appears as a thinner dark broken layer below Navajo Sandstone and above Wingate Sandstone (all three formations are in the same group). Together, these three formations can result in immense vertical cliffs of 600 metres (2,000 ft) or more. Kayenta layers are typically red to brown in color, forming broken ledges.

## Kayenta Formation in Utah
### Southeast Utah

In most sections that include all three geologic formations of the Glen Canyon group the Kayenta is easily recognized. Even at a distance it appears as a dark-red, maroon, or lavender band of thin-bedded material between two thick, massive, cross bedded strata of buff, tan, or light-red color. Its position is also generally marked by a topographic break. Its weak beds form a bench or platform developed by stripping the Navajo sandstone back from the face of the Wingate cliffs. The Kayenta is made up of beds of sandstone, shale, and limestone, all lenticular, uneven at their tops, and discontinuous within short distances. They suggest deposits made by shifting streams of fluctuating volume. The sandstone beds, from less than 25 millimetres (1 in) to more than 3 metres (10 ft) thick, are composed of relatively coarse, well-rounded quartz grains cemented by lime and iron. The thicker beds are indefinitely cross bedded. The shales are essentially fine-grained, very thin sandstones that include lime concretions and balls of consolidated mud. The limestone appears as solid gray-blue beds, a few inches to a few feet thick, and as lenses of limestone conglomerate. Most of the limestone lenses are less than 8 metres (25 ft) long, but two were traced for nearly 150 metres (500 ft) and one for 500 metres (1,650 ft).
Viewed as a whole, the Kayenta is readily distinguished from the geologic formations above and below it. It is unlike them in composition, color, manner of bedding, and sedimentary history. Obviously the conditions of sedimentation changed in passing from the Wingate Sandstone formation to the Kayenta and from the Kayenta to the Navajo sandstone, but the nature and regional significance of the changes have not been determined. In some measured sections the transition from Wingate to Kayenta is gradual; the material in the basal Kayenta, beds seems to have been derived from the Wingate immediately below and redeposited with only the discordance characteristic of fluviatile sediments. But in many sections the contact between the two formations is unconformable; the basal Kayenta consists of conglomerate and lenticular sandstone that fills depressions eroded in the underlying beds. In Moqui Canyon near Red Cone Spring nearly 3 metres (10 ft) of Kayenta limestone conglomerate rests in a long meandering valley cut in Wingate. Likewise, the contact between the Kayenta and the Navajo in places seems to be gradational, but generally a thin jumbled mass of sandstone and shales, chunks of shale and limestone, mud balls, and concretions of lime and iron, lies at the base of the fine-grained, cross bedded Navajo. Mud cracks, a few ripple marks, and incipient drainage channels were observed in the topmost bed of the Kayenta on Red Rock Plateau; and in west Glen Canyon, wide sand-filled cracks appear at the horizon. These features indicate that, in places at least, the Wingate and Kayenta were exposed to erosion before their overlying geologic formations were deposited, are it may be that the range in thickness of the Kayenta thus in part (is) accounted for.

### Southwest Utah

The red and mauve Kayenta siltstones and sandstones that form the slopes at base of the Navajo Sandstone cliffs record the record of low to moderate energy streams. Poole (1997) has shown that the streams still flowed toward the east depositing from 150 to 210 m (500 to 700 ft) of sediment here. The sedimentary structures showing the channel and flood plain deposits of streams are well exposed on switchbacks below the tunnel in Pine Creek Canyon.
In the southeastern part of Zion National Park a stratum of cross bedded sandstone is found roughly halfway between the top and bottom of the Kayenta Formation. It is a "tongue" of sandstone that merges with the Navajo formation east of Kanab, and it shows that desert conditions occurred briefly in this area during Kayenta time. This tongue is the ledge that shades the lower portion of the Emerald Pool Trail, and it is properly called Navajo, not Kayenta.
Fossil mudcracks attest to occasional seasonal climate, and thin limestones and fossilized trails of aquatic snails or worms mark the existence of ponds and lakes. The most interesting fossils, however, are the dinosaur tracks that are relatively common in Kayenta mudstone.
These vary in size, but all seem to be the tracks of three-toed reptiles that walked upright, leaving their tracks in the muds on the flood plains. Unfortunately, so far no bone materials have been found in Washington County that would enable more specific identification.
Apparently during Kayenta time Zion was situated in a climatic belt like that of Senegal with rainy summers and dry winters at the southern edge of a great desert. The influence of the desert was about to predominate, however, as North America drifted northward into the arid desert belt.

## Glen Canyon

The Kayenta Formation is approximately 120 metres (400 ft) thick and consists of a fine-grained sandstone interbedded with layers of siltstone. The alternation of these units generally produces a series of ledges and slopes between the cliffs of the Navajo and Moenave formation. Dinosaur tracks are fairly common in the siltstone, and fresh water mussels and snails occur but are rare. The Kayenta Formation is colored pale red and adds to the splendor of the Vermilion Cliffs. It accumulated as deposits of rivers.

## Fossils

| 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. |

### Invertebrates

| Genus | Species | Location | Stratigraphic position | Material | Notes |
| Darwinula | D. magna D.sarytirmensis | Gold Spring Quarry 1 | Base of the "typical facies" | Valves | A freshwater (lacustrine or fluvial) ostracod, type member of the family Darwinulidae. Kayenta specimens have a distinctive columnar calcitic layer. The Kayenta fauna is similar to the Sinemurian faunas of the Toutunhe Formation of Xinjiang, China. |
| Liratina | L. sp. | Gold Spring Quarry 1 | Base of the "typical facies" | Single shell | A freshwater (lacustrine or fluvial) snail, incertae sedis inside Mesogastropoda. Differs considerably from the species from the Upper Jurassic Morrison Formation, Liratina jurassicum |
| Lymnaea | L. hopii | Colorado Plateau | Base of the "typical facies" | Shells | A freshwater (lacustrine or fluvial) snail, member of the family Lymnaeidae. |
| Scabriculocypris | S. n. sp | Gold Spring Quarry 1 | Base of the "typical facies" | Valves | A freshwater (lacustrine or fluvial) ostracod, incertae sedis inside Cypridacea. Differs from all other described species of the genus in being more elongate and from most in being spinose. |
| Unio | U. dumblei U. dockumensis U. iridoides | South of Moab | Base of the "typical facies" | Shells | A freshwater (lacustrine or fluvial) Bivalve, member of the family Unionidae. |
| Valvata | V. gregorii | Colorado Plateau | Base of the "typical facies" | Shells | A freshwater (lacustrine or fluvial) snail, member of the family Valvatidae. |

### Fishes

The "Kayenta Fish Fauna" is the last one recovered from the Glen Canyon Group sequence and it is delimited mostly to the silty facies of the Lower-Middle Part of the formation. This Fauna is rather scarce and delimited to several concrete locations with proper lacustrine or fluvial deposition, and are also scarce due to preservation bias. Another aspect that can explain the lack of fish fossils found is the use of different research techniques than used on the Chinle Formation.

#### Chondrichthyes

| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Hybodontoidea | Indeterminate | Shonto Trading Post, Segi Canyon Ward Terrace | Base of the "typical facies" | UCMP 136104, 136105 + ten uncatalogued specimens, teeth | A freshwater (lacustrine or fluvial) non-neoselachian shark, incertae sedis inside Hybodontoidea. The remains of sharks are rather rare on the formation and limited to several locations with typical lacustrine or fluvial floodplain deposition. | |
| Toarcibatidae (= "Archaeobatidae") | Indeterminate | Gold Spring Quarry 1 | Base of the "typical facies" | Isolated Tooth | A freshwater (lacustrine or fluvial) toarcibatid. Related originally with Micropristis or Libanopristis, and stated to be reworked from younger Cretaceous deposits, was found due to its asymmetrical cusp to fit within the definition of Toarcibatis, being more likely to be native of the formation. | |

#### Actinopterygii

| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Lophionotus | L. kanabensis | Washington Dome Ward Terrace Warner Valley Zion National Park | Base of the "typical facies" | Fragmentary Specimens, Isolated Teeth and Scales | A freshwater (lacustrine or fluvial) semionotid semionotiform. | |
| "Palaeoniscidae" | Indeterminate | Utah Route 7 near St.George Warner Valley | Base of the "typical facies" | Isolated Ganoid Scales& Teeth | A freshwater (lacustrine or fluvial) palaeoniscid palaeonisciform. | |
| Semionotidae | Indeterminate | Utah Route 7 near St.George Downtown Moab Warner Valley Washington Dome Ward Terrace Warner Valley Zion National Park Desert Tortoise tracksite 1 | Base of the "typical facies" | Large (1 m) Complete specimen; Isolated Ganoid Scales & Teeth | A freshwater (lacustrine or fluvial) semionotid semionotiform, probably related to the genus Semionotus. Semionotiformes are the only properly identified bony fishes from the formation, including a large specimen exposed at the Dan O’Laurie Museum. | Semionotus is probably related to the Kayenta Seminotiformes |

#### Sarcopterygii

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Ceratodus | C. stewarti | Goblin Valley State Park | Middle “Silty Facies” | OMNH 69332, left pterygopalatine plate | A freshwater (lacustrine or fluvial) ceratodontid dipnomorph (lungfish). | Ceratodus |
| Coelacanthidae | Indeterminate | Tsegi Canyon Warner Valley | Base of the "typical facies" | Isolated remains & Scales | A freshwater (lacustrine or fluvial) coelacanthid Coelacanthiform. Coelacanths are quoted from this zone, but their remains have not been studied. | |
| Potamoceratodus | P. guentheri | Tsegi Canyon? Little Colorado River Valley on Ward Terrace | Middle “Silty Facies” | Single dipnoan tooth plate (MCZ 13865) | A freshwater (lacustrine or fluvial) ceratodontid dipnomorph (lungfish). Was described as C. felchi, know from the Upper Jurassic Morrison Formation. Other dipnoan specimens have been cited but never described. | |

### Amphibia

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Anura | Indeterminate | Gold Spring Quarry 1 | Silty Facies Member | MCZ 9019, distal humerus MCZ 9020–24, ilia | An early frog, incertae sedis relationships | |
| Eocaecilia | E. micropodia | Gold Spring Quarry 1 | Silty Facies Member | MNA V8066 (type), Nearly complete skull and lower jaw Isolated multiple specimens, craneal and postcraneal: MNA V8053, 8054, 8055... | A genus whose relationships are controversial, being considered one of the earliest gymnophionans as a close relative of caecilians | Eocaecilia |
| Lissamphibia | Indeterminate | Gold Spring Quarry 1 | Silty Facies Member | MCZ 9025–9028, jaws; MCZ 9031, 9032, vertebrae MCZ 9035, atlas vertebra; MCZ 9034 + 4 uncatalogued specimens, proximal femora MCZ 9066, 9067, proximal humeri MCZ 9068–9072, proximal limb bones, possibly humeri | Incertae sedis relationships | |
| Prosalirus | P. bitis | Gold Spring Quarry 1 | Silty Facies Member | MNA V 8725, associated desarticulated remains of 2 individuals; referred MCZ 9324 A & MCZ 9323 A | An early frog, probably related to Notobatrachidae | Prosalirus |
| Urodela | Indeterminate | Gold Spring Quarry 1 | Silty Facies Member | MCZ 9017, 9018, atlas vertebrae | A possible stem-salamander, incertae sedis inside Urodela. The oldest record of an urodelan from North America | |

### Reptilia
#### Rhynchocephalia

| Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Navajosphenodon | N. sani | Gold Springs Quarry Silty Facies Main Quarry Adeii Eechii Cliffs | Silty Facies | MNA.V.12442, a fully articulated skeleton, including the skull, mandibles, axial and appendicular skeleton Referred multiple specimens MCZ VP 9098, MCZ VP 101562, MCZ VP 9099, MCZ VP 101564, MCZ VP 101575, MCZ VP 9094, MCZ VP 9102, MCZ VP 9103, MCZ VP 101569, MCZ VP 101563, MNA.V.8726, MNA.V.8727 | An Advanced Sphenodont, member of Sphenodontinae. The skeleton of N. sani shows a large number of similarities with the modern tuatara S. punctatus, clustering them closely together in the morphospace of sphenodontians and early lepidosaurs. | Navajosphenodon |
| Rhynchocephalia | Indeterminate | Airhead West | Silty Facies | Uncertain Fragments | Rhynchocephalians of uncertain assignment | |
| Sphenodontia | Indeterminate | Gold Spring Quarry 1 | Silty Facies | MCZ 9036 through 9040, jaw fragments | An indeterminate sphenodont | |

#### Testudinatans

| Genus / taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Cryptodira | Indeterminate | Red Knob | Silty Facies | Uncertain fragments | Cryptodirans of uncertain assignment | |
| Kayentachelys | K. aprix K. spp. | Gold Spring Quarry 1 Gold Spring South Gold Spring General Gold Spring Wash Hummingbird Canyon Ted's Turtle Town Gerald's Turtle | Silty Facies Member | MNA V1558, complete skull only lacking the right temporal arch and mandible Referred multiple craneal and postcraneal material: MNAV2664, TMM 436701–3, TMM 43656-1... | A mesochelydian | Kayentachelys |
| Testudinata | Indeterminate | Airhead West Gold Spring General Moenkopi Point Valley of the Buttes Paiute Canyon General East Paiute Valley | Silty Facies | Uncertain fragments | Testudinatans of uncertain assignment | |

#### Crocodylomorphs

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes |
| Calsoyasuchus | C. valliceps | Adeii Eechii Cliffs, Navajo Nation | Silty Facies | TMM 43631-1 (holotype), partial skull | A terrestrial member of the Hsisosuchidae. Alternatively can be a relative of Thalattosuchia |
| Crocodylomorpha | "Undescribed new genus" Indeterminate | Utah Route 7 near St.George Airhead West Moenkopi Point, Pumpkin Patch Blue layer, Silty Facies Gold Spring Quarry 1 | Silty Facies | Teeth (+30) UCMP 97639, 97640 MCZ 9044, dermal armor fragment MCZ 9199, fragment of pseudosuchian dermal scute MCZ 9200, dermal scute, probably Eopneumatosuchus UCMP 136102, fragment of lower jaw | Indeterminate crocodylomorphs. Includes a new taxon with skull similar to Orthosuchus stormbergi. |
| Eopneumatosuchus | E. colberti | Blue layer, Silty Facies | Silty Facies | MNA P1.2460, partial skull Isolated Jaw | An early terrestrial or semiterrestrial protosuchid crocodylomorph |
| Kayentasuchus | K. walkeri | Warner Valley Willow Springs 13 | Silty Facies | UCMP 131830, nearly complete skeleton UMNH VP 21923 | An early terrestrial or semiterrestrial crocodylomorph |
| Protosuchidae | "Gomphosuchus wellesi" "Edentosuchus-like taxon" | Moenkopi Point, Pumpkin Patch Blue layer, Silty Facies | Silty Facies | MCZ 8816, mandible UCMP 97638, A skull and articulated mandible UCMP 125395: A cranium. UCMP 125871: Skull with mandibles and one epibranchial lacking the dorsal part of the braincase, articulated with the atlas, axis, and 2 cervical vertebrae. UCMP 125358 UCMP 125359: An eroded compressed braincase. UCMP 125872: A right jugal and maxilla in articulation in a large block of unprepared material. UCMP 125870: A very well-preserved braincase UCMP 130082 | Early terrestrial or semi-terrestrial herbivorous Crocodylomorphs. Includes two taxa similar to the Cretaceous Edentosuchus tienshanensis, one that has been referred to informally as "Gomphosuchus" (including UCMP 97638 and UCMP 125871) and another unnamed taxon (including UCMP 130082). Previously considered one taxon (the 'Kayenta form') in older literature. |

#### Dinosaurs

Indeterminate ornithischian remains located in Arizona, USA. Ornithischian tracks located in Arizona, USA. Indeterminate theropod remains located in Arizona, US. Theropod tracks located in Arizona and Utah, US. Possible theropod tracks located in Arizona, Colorado, and Utah, US.

##### Ornithischians

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Heterodontosauridae | Indeterminate | Gold Springs | Silty Facies | MCZ 9092, complete upper and lower dentitions, many other portions of the skull, vertebrae from all portions of the axial column, and portions of fore and hind girdles and limbs | A heterodontosaurid of uncertain placement. Appears to have been an insectivore downsized to a degree not seen before among early dinosaurs. | |
| Ornithischia | Laquintasaura-like Indeterminate | Utah Route 7 near St.George Gold Spring Quarry | Silty Facies | MNA.V.109, a large left femur Isolated Teeth (+20) | A uncertain placement large ornithischian and teeth from diverse type of genera. The femur was assigned to Dilophosaurus wetherilli. The femur resembles that of the early neornithischian Lesothosaurus. | |
| Scelidosaurus | S. sp. (S. "arizonensis") | Valley of the Buttes | Silty Facies | UCMP 130056, scutes | A controversial thyreophoran, resembles the osteoderms of S. harrisonii. | |
| Scutellosaurus | S. lawleri | Paiute North West Moenkopi Plateau Paiute Canyon General East Paiute Valley Southwest Paiute Canyon Rock Head Willow Spring General Gold Spring General Gold Spring Quarry Gold Spring South Gerald's Turtle Ted's Turtle Town Hummingbird Canyon | Silty Facies | MNA P1.175, almost complete skeleton (holotype) MNA P1.1752, partial skeleton (paratype) Referred multiple specimens: TMM 43669-5/6, TMM 43661-1, TMM 43691-18, TMM 43691-20, TMM 43648-13, TMM 43663-1, TMM 43664-1, 2, TMM 47001-1, TMM 43690-6, TMM 43687-13, 117, 123... | A basal thyreophoran, the most abundant dinosaur of the formation | Scutellosaurus |

##### Sauropodomorphs

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Sarahsaurus | S. aurifontanalis | Gold Springs Rock Head | Silty Facies | TMM 43646–2 partially articulated skeleton TMM 43646–3, partial skeleton MCZ 8893, articulated skull with fragmentary postcranial elements | A sauropodomorph, a member of the family Massospondylidae. Originally thought to be Massospondylus | Sarahsaurus |

##### Theropods

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Coelophysidae | Unnamed, informally known as the "Shake-N-Bake" coelophysid | Rock Head (Bowl Area) Shake-N-Bake | Silty Facies | MCZ 8817 dorsal, cervical, caudal vertebra, partial sacrum, partial pelvis, partial tooth, partial caudal centrum, proximal femur, distal tibiotarsus, distal fibula, partial astragalus, partial scapulocoracoid MCZ 9442; sacrum, partial ilia, proximal pubes, proximal ischia MCZ 9463; distal tibiotarsus TMM 43689-4; proximal tarsometatarsus MNA V3181; pubis | A coelophysid neotheropod. | |
| Coelophysis | C. kayentakatae | Rock Head (Bowl Area) Gold Spring Wash Shake-N-Bake | Silty Facies | MNI; MNA V2623 TMM 43669-3 MNA V100, V140 | A coelophysid neotheropod. Referred to as Syntarsus by Weishampel et al. Formerly known as Megapnosaurus. | Coelophysis kayentakatae |
| Dilophosaurus | D. wetherilli | Tuba City, Silty Facies Dilophosaurus Quarry Gold Spring East Gold Spring General Rock Head (Bowl Area) Moenkopi Point, Pumpkin Patch | Silty Facies | UCMP 37302 (holotype), nearly complete skeleton UCMP 37303, partial skeleton; third skeleton eroded and not collected MNA V3145, disal end of R femur Referred TMM 43687-52; UCMP 77270; UCMP 130053; TMM 43646-0, 1; TMM 47006-1 | An advanced neotheropod, type member of the family Dilophosauridae. Dilophosaurus is the main identified dinosaur from the formation, being both the most known and studied. It was among the largest theropods present locally, and very likely an active hunter, rather than a fisher. | Dilophosaurus |
| Kayentavenator | K. elysiae | Willow Springs | Silty Facies | UCMP V128659, six proximal caudal centra, three centra, two partial neural arches, fragmentary ilium, proximal pubes, pubic shaft fragments, incomplete femora, proximal tibiae, proximal fibula, fragments | A neotheropod of uncertain relationships, probably a coelophysoid. Originally referred to M. kayentakatae by Rowe. | Kayentavenator |
| Theropoda | Indeterminate | ARCH 71v, near the Garden of Eden Utah Route 7 near St.George Airhead West Gold Spring General Gold Spring Wash | Silty Facies | ARCH 4012, fragmentary skeletal Isolated Teeth (+50) TMM 43669-10 TMM 43687-10, 58, 60, 71, 85, 91, 98, 102, 105, 119 | Incertae sedis within Theropoda, probably Neotheropoda | |

#### Pterosauria

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Pterosauria | Indeterminate | Utah Route 7 near St.George | Silty Facies | Teeth | Possible pterosaur teeth | |
| Rhamphinion | R. jenkinsi | Airhead West MCZ 23/78A, Foxtrot Mesa | Silty Facies, Ward Mesa | MNA V 4500 (holotype), skull fragments UCMP 128227, left fourth wing metacarpal | A pterosaur, considered a member of the family Dimorphodontidae. Was originally classified as a "rhamphorhynchoid", represents the only major pterosaur identified from the formation and one of the oldest from North America. | |

### Synapsida

| Genus / Taxon | Species | Location | Stratigraphic position | Material | Notes | Images |
| Dinnebitodon | D. amarali D. spp. | Dinnebito Wash Hummingbird Canyon Gold Spring General | Silty Facies | MNA V3222 (Type, partial skull and associated postcrania) Referred MNA V3223, partial skull and scapula; MCZ 8831 includes two left dentaries; MCZ 8830, Crushed snout; TMM 43647-3, 4, TMM 43687-7 | A relatively large and common tritylodont | |
| Dinnetherium | D. nezorum | Gold Spring Quarry 1 | Silty Facies | MNA V3221; MCZ 20870-20877 | A mammaliaform, member of the family Megazostrodontidae | |
| Haramiyidae | Indeterminate | Gold Spring Quarry 1 | Silty Facies | MCZ 20879 | Incertae sedis, a possible haramiyid | |
| Kayentatherium | K. wellesi K. spp. | MCZ, The Landmark Hummingbird Canyon Gold Spring General Gold Spring wash Willow Spring General Rock Head, general area | Silty Facies | MCZ 8812, well-preserved partial skeleton of a large individual Referred TMM 43669-9; MCZ 8842; TMM 43647-9, 10; TMM 43687-111 | A Large tritylodont, with a suggested semiaquatic mode of life. A specimen has been recovered with several associated perinates. | Kayentatherium |
| Morganucodon | M. sp. | Gold Spring Quarry 1 | Silty Facies | MCZ 20878 | A mammaliaform, member of the family Morganucodontidae | Morganucodon |
| Oligokyphus | O. sp. cf. O. sp. | Gold Spring General Gold Spring Quarry 1 | Silty Facies | TMM 43687-86 Referred > 42 specimens | A tritylodont, also present on coeval deposits from Asia and Europe. | Oligokyphus |
| Tritylodontidae | Indeterminate | Airhead West MCZ, The Landmark Rock Head, general area Willow springs Gold Spring General Gold Spring 1 | Silty Facies | Teeth | Indeterminate tritylodontid remains | |

### Ichnofossils

| Genus | Species | Location | Material | Type | Origin | Notes | Images |
| Anomoepus | A. scambus A. shingi A. moabensis A. isp. | Moenkopi Wash Lisbon Valley Oilfield tracksite Hamblin tracksite Warner Valley tracksite Utah Route 7 near St.George Poison Spider Mesa tracksite | Footprints | Moving Tracks | Ornithischians | Ornithischian Footprints of the ichnofamily Moyenisauropodidae. | |
| Batrachopus | B. isp. | Desert Tortoise tracksite | Tracks | Moving Tracks | Crocodrylomorphs | Pseudosuchia Footprints of the ichnofamily Batrachopodidae. | |
| Characichnos | C. isp. | Utah Route 7 near St.George | Tracks | Moving Trails | Dinosaurs | Dinosaur Traces left while swimming | |
| Dilophosauripus | D. williamsi D. isp. | Moenkopi Wash 4 tracksite Moenave Road Tracksite Goldtooth Spring tracksite Cameron tracksite | Footprints | Moving Tracks | Theropods (Dilophosaurus?) | Theropod Footprints of the ichnofamily Grallatoridae. | |
| Dinosauropedida | Indeterminate | North Creek tracksite Parunuweap-West Temple tracksite Tenmile Canyon tracksite | Footprints | Moving Tracks | Dinosaurs | Possible Dinosaur Footprints, non assigned to any concrete ichnogenus | Example of Indeterminate Dinosaur Footprint from the Kayenta Formation |
| Eubrontes | E. giganteus E. isp. | Washington City Water Tank tracksite 1 Flat Iron Mesa tracksite Trout Water Canyon tracksite Grapevine Pass Wash Tracksite Warner Valley tracksite Desert Tortoise tracksite Flag Point I tracksite Rainbow Bridge tracksite Explorer's Canyon tracksite Mike's Mesa tracksite (Kayenta) Utah Route 7 near St.George Cactus Park track site | Footprints | Moving Tracks | Theropods (Dilophosaurus?) | Theropod Footprints of the ichnofamily Grallatoridae. This type of tracks match with Dilophosaurus pes | |
| Grallator | G. tenuis G. isp. | Lisbon Valley Oilfield tracksite Washington City Water Tank tracksite 1 Exit 13 North tracksite Exit 13 South tracksite Desert Tortoise site Warner Valley tracksite Desert Tortoise tracksite Flag Point II tracksite Utah Route 7 near St.George Flat Iron Mesa tracksite Cactus Park track site | Footprints | Moving Tracks | Theropods (Coelophysoids?) | Theropod Footprints of the ichnofamily Grallatoridae. Likely from smaller local theropods | |
| Kayentapus | K. hopii K. soltykovensis K. isp. | Moenkopi Wash Trout Water Canyon tracksite Desert Tortoise tracksite Flag Point I tracksite Flag Point II tracksite Flat Iron Mesa tracksite | Footprints | Moving Tracks | Theropods | Theropod Footprints of the ichnofamily Grallatoridae. | |
| Limulidae | Indeterminate | Lisbon Valley Oilfield tracksite | Trackways | Moving Tracks | Limuloids Insects? | Saltwater/Blackish-linked tracks with resemblance with extant Xiphosuran traces | |
| Moyenisauropus | M. isp. | Utah Route 7 near St.George | Footprints | Moving Tracks | Thyreophorans | Ornithischian Footprints of the ichnofamily Moyenisauropodidae. | |
| Otozoum | O. isp. | Flat Iron Mesa tracksite Poison Spider Mesa tracksite | Footprints | Moving Tracks | Sauropodomorphs | Theropod Footprints of the ichnofamily Otozoidae. Includes tracks referable to bipedal Sauropodomorphs | |
| Planolites | P. isp. | Near St. George, Washington County | Cylindrical burrows | Pascichnia | Annelids | Burrow-like ichnofossils. It is referred to vermiform deposit-feeders. It is controversial, since is considered a strictly a junior synonym of Palaeophycus. | Example of Planolites fossil |
| Skolithos | S. isp. | Near St. George, Washington County | Cylindrical to subcylindrical Burrows | Domichnia | Annelids Crustaceans Fishes | Burrow-like ichnofossils. Ichnofossils done by organisms advancing along the bottom surface. Very narrow, vertical or subvertical, slightly winding unlined shafts filled with mud. Interpreted as dwelling structures of vermiform animals, more concretely the Domichnion of a suspension-feeding Worm or Phoronidan, with certain Skolithos representing entrance shafts to more complicated burrows. | Skolithos ichnofosil reconstruction, with possible fauna associated |
| Synapsidipedia | Indeterminate | Lisbon Valley Oilfield tracksite | Tracks | Moving Tracks | Mammaliformes Tritylodonts | Possible Synapsid Footprints, non assigned to any concrete ichnogenus | |
| Taenidium | T. isp | Near St. George, Washington County | Unlined meniscate burrows | Fodinichnia | Deposit-feeding Sipuncula Annelids | Saltwater/Blackish burrow-like ichnofossils. Taenidium is a meniscate backfill structure, usually considered to be produced by an animal progressing axially through the sediment and depositing alternating packets of differently constituted sediment behind it as it moves forward. | |
| Theropodipedia | Indeterminate | Lisbon Valley Oilfield tracksite Hamblin tracksite South Gate tracksite Long Canyon tracksite Washington City Water Tank tracksite 2 Lion's Back tracksite | Footprints | Moving Tracks | Theropods | Possible Theropod Footprints, non assigned to any concrete ichnogenus | Example of Indeterminate Theropod Footprint from the Kayenta Formation |
| Undichna | U. isp. | Utah Route 7 near St.George | Trails | Moving Trails | Bony Fishes | Fish-swimming fossil trail left as a fossil impression on a substrate | |

### Plants

| Genus | Species | Stratigraphic position | Material | Notes | Images |
| Clathropteris | C. sp. | Utah Route 7 near St.George | Leaflets | Affinities with Dipteridaceae inside Polypodiales. | Example of Clathropteris meniscioides specimen |
| Cycadidae | Indeterminate | Utah Route 7 near St.George | Leaflets | Affinities with Cycadidae inside Cycadopsida. | Example of extant cycad, Encephalartos longifolius |
| Otozamites | O. sp. | Utah Route 7 near St.George | Leaflets | Affinities with Williamsoniaceae inside Bennettitales. | |
| Pinopsida | Indeterminate | Utah Route 7 near St.George | Leave Compressions Isolated Cones | Affinities with Pinopsida inside Pinaceae. | |
| Zamites | Z. powellii | Utah Route 7 near St.George | Leaflets | A member of Williamsoniaceae inside Bennettitales. It has been interpreted as a cycad in the family Cycadaceae or a Bennettitalean plant, and also a late surviving member of Noeggerathiales. | Example of Zamites mandelslohi specimen |