Kayenta Formation
Stratigraphic range: Sinemurian-Toarcian
~
Kayenta Formation, Capitol Reef National Park, Utah.
TypeGeological formation
Unit ofGlen Canyon Group
UnderliesNavajo Sandstone
OverliesWingate Sandstone
Thickness100 to 120 metres (330 to 390 ft)
Lithology
PrimarySandstone
OtherSiltstone, Limestone
Location
Coordinates37°48′N 110°36′W / 37.8°N 110.6°W / 37.8; -110.6
CountryUnited States
Extentnorthern Arizona, northwest Colorado, Nevada, and Utah[1]
Type section
Named forKayenta, Arizona
Kayenta Formation west of Tuba City, Arizona.

The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Traditionally has been suggested as 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.[2] A previous depth work recovered a solid "Carixian" (Lower-Middle Pliensbachian) age from measurements done in the Tenney Canyon.[3] 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.[4] 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.[4]

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 2,000 feet (610 m) or more. Kayenta layers are typically red to brown in color, forming broken ledges.

Kayenta Formation in Utah

Southeast Utah

Redbeds including the Kayenta Formation and the Navajo Sandstone in Kolob Canyons, Zion National Park, Utah, USA
The Permian through Jurassic stratigraphy of the Colorado Plateau area of southeastern Utah that makes up much of the famous prominent rock formations in protected areas such as Capitol Reef National Park and Canyonlands National Park. From top to bottom: Rounded tan domes of the Navajo Sandstone, layered red Kayenta Formation, cliff-forming, vertically jointed, red Wingate Sandstone, slope-forming, purplish Chinle Formation, layered, lighter-red Moenkopi Formation, and white, layered Cutler Formation sandstone. Picture from Glen Canyon National Recreation Area, 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 1-inch (25 mm) to more than 10 feet (3.0 m) 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 25 feet (7.6 m) long, but two were traced for nearly 500 feet (150 m) and one for 1,650 feet (500 m).

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 10 feet (3.0 m) 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 about 700 feet) 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 400 feet (120 m) 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 Images

Darwinula[5]
  • Darwinula magna
  • Darwinula 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[5]
  • Liratina 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[6]
  • Lymnaea hopii
  • Colorado Plateau

Base of the "typical facies"

Shells

A freshwater (lacustrine or fluvial) snail, member of the family Lymnaeidae.

Scabriculocypris[5]

Scabriculocypris 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[7]
  • Unio dumblei
  • Unio dockumensis
  • Unio iridoides
  • South of Moab

Base of the "typical facies"

Shells

A freshwater (lacustrine or fluvial) Bivalve, member of the family Unionidae.

Valvata[6]
  • Valvata 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.[8] 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.[8] Another aspect that can explain the lack of fish fossils found is the use of different research techniques than used on the Chinle Formation.[8]

Chondrichthyes

Taxon Species Location Stratigraphic position Material Notes Images

Hybodontoidea[9]

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")[10]

Toarcibatidae 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.[10]

Actinopterygii

Taxon Species Location Stratigraphic position Material Notes Images

Lophionotus[11]

Lophionotus kanabensis
  • Washington Dome
  • Ward Terrace
  • Warner Valley
  • Zion National Park

Base of the "typical facies"
  • Fragmentary Specimens
  • Isolated Scales

A freshwater (lacustrine or fluvial) semionotid semionotiform.

Palaeoniscidae[8][12][13]

Palaeoniscidae indeterminate
  • Utah Route 7 near St.George
  • Warner Valley

Base of the "typical facies"
  • Utah Route 7 near St.George
  • Isolated Ganoid Scales
  • Teeth

A freshwater (lacustrine or fluvial) palaeoniscid palaeonisciform.

Semionotidae[8][12][13]

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.[8]
Semionotus is probably related to the Kayenta Seminotiformes

Sarcopterygii

Genus / Taxon Species Location Stratigraphic position Material Notes Images

Ceratodus[8][14]

Ceratodus stewarti
  • Goblin Valley State Park

Middle “Silty Facies”
  • OMNH 69332, left pterygopalatine plate

A freshwater (lacustrine or fluvial) ceratodontid dipnomorph (lungfish).
Ceratodus

Coelacanthidae[14][12]

Coelacanthidae indeterminate

  • Tsegi Canyon
  • Warner Valley

Base of the "typical facies"

Uncertain Remains

A freshwater (lacustrine or fluvial) coelacanthid Coelacanthiform. Coelacanths are quoted from this zone, but their remains have not been studied.

Potamoceratodus[15]

Potamoceratodus 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.[14]

Amphibia

Genus / Taxon Species Location Stratigraphic position Material Notes Images

Anura[9]

Anura Indeterminate

Gold Spring Quarry 1

Silty Facies Member

MCZ 9019, distal humerus; MCZ 9020-24, ilia

An early frog, incertae sedis relationships

Eocaecilia[16]

Eocaecilia micropodia

Gold Spring Quarry 1

Silty Facies Member

MNA V8066 (type); MNA V8053, 8054, 8055, 8057, 8058, 8059, 8060, 8062, 8063, 8064, 8065, 8066, 8067, 8068, 8069, 8070, 8071, 8072, 8073, 9346; MCZ 9011A, 9015, 9095, 9152, 9156. 9158, 9163, 9166, 9167, 9169A, 9171A, 9173, 9231A, 9233, 9235, 9237, 9238A, 9241, 9242

A genus whose relationships are controversial, being considered one of the earliest gymnophionans as a close relative of caecilians
Eocaecilia

Lissamphibia[9]
  • Lissamphibia indeterminate
  • 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[17]

Prosalirus bitis

Gold Spring Quarry 1

Silty Facies Member

MNA V 8725 (type), MCZ 9324 A, MCZ 9323 A

An early frog, probably related to Notobatrachidae
Prosalirus

Urodela[9]

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[18]

Navajosphenodon 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 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.[18]
Navajosphenodon

Rhynchocephalia[19]

Rhynchocephalia Indeterminate

Airhead West

Silty Facies

Uncertain Fragments

Rhynchocephalians of uncertain assignment

Sphenodontia[9]

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[9]

Cryptodira indeterminate

Red Knob

Silty Facies

Uncertain fragments

Cryptodirans of uncertain assignment

Kayentachelys[20]
  • Kayentachelys aprix
  • Kayentachelys sp.
  • Cf.Kayentachelys sp.
  • 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
  • TMM 43669-1, 2, 4
  • TMM 436701–3
  • TMM 43656-1, 4
  • TMM 45608-2
  • TMM 43687-1, 4–5, 12, 21, 25–35, 37–41, 47–49, 54
  • TMM 43687-24, 43, 54

A mesochelydian
Kayentachelys

Testudinata[9][19]

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 Images

Calsoyasuchus[21]

Calsoyasuchus 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[9][13]
  • Crocodylomorpha "undescribed new genus"
  • Crocodylomorpha 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[22]

Eopneumatosuchus colberti

Blue layer, Silty Facies

Silty Facies
  • MNA P1.2460, partial skull
  • Isolated Jaw

An early terrestrial or semiterrestrial protosuchid crocodylomorph

Kayentasuchus[23][12]

Kayentasuchus walkeri
  • Warner Valley
  • Willow Springs 13

Silty Facies
  • UCMP 131830, nearly complete skeleton
  • UMNH VP 21923

An early terrestrial or semiterrestrial crocodylomorph

Protosuchidae[9][24]
  • "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).[25][26] Previously considered one taxon (the 'Kayenta form') in older literature.

Dinosauria

Indeterminate ornithischian remains located in Arizona, USA.[27] Ornithischian tracks located in Arizona, USA.[27] Indeterminate theropod remains located in Arizona, US.[27] Theropod tracks located in Arizona and Utah, US.[27] Possible theropod tracks located in Arizona, Colorado, and Utah, US.[27]

Genus / Taxon Species Location Stratigraphic position Material Notes Images

Coelophysidae[28]

Unnamed, informally known as the "Shake-N-Bake" coelophysid

  • Rock Head (Bowl Area)
  • Shake-N-Bake

Silty Facies
  • MCZ 8817b dorsal vertebra, partial sacrum, partial pelvis
  • MCZ 8817c two partial mid cervical vertebrae
  • MCZ 8817d incomplete posterior cervical vertebra
  • MCZ 8817e proximal caudal vertebra
  • MCZ 8817f) partial tooth, partial caudal centrum
  • MCZ 8817g) anterior dorsal vertebra
  • MCZ 8817h) incomplete anterior dorsal vertebra
  • MCZ 8817i) partial sacrum
  • MCZ 8817j) proximal femur
  • MCZ 8817k) (robust) proximal femur
  • MCZ 8817l) (gracile) proximal femur
  • MCZ 8817m) distal tibiotarsus
  • MCZ 8817n) distal tibiotarsus, distal fibula
  • MCZ 8817o) distal tibiotarsus, distal fibula
  • MCZ 8817p) distal tibiotarsus
  • MCZ 8817q) distal tibia, partial astragalus
  • MCZ 8817r) partial scapulocoracoid
  • MCZ 8817t) partial scapulocoracoid
  • MCZ 9442; = 8817a) (adult) sacrum, partial ilia, proximal pubes, proximal ischia
  • MCZ 9463; = 8817m-p?) (adult) distal tibiotarsus
  • TMM 43689-4) (adult) proximal tarsometatarsus
  • MNA V3181, pubis

A coelophysid neotheropod.

Coelophysis[29][30]

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.[27] Formerly known as Megapnosaurus.
Coelophysis kayentakatae

Dilophosaurus[31][32]

 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
  • 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.[32]
Dilophosaurus

Heterodontosauridae[33][34]

Heterodontosauridae indeterminate

Gold Springs

Silty Facies

MCZ 9092, Partial Skull & Associated Remains (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)[34]

A heterodontosaurid of uncertain placement. Its presence in North America suggest early dispersal of the family.

Kayentavenator[35]

Kayentavenator elysiae[35]

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

Ornithischia[36][13][37]
  • 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.[36] The femur resembles that of the early neornithischian Lesothosaurus.[37]

Sarahsaurus[33][38]

Sarahsaurus aurifontanalis[27]
  • 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[27]
Sarahsaurus

Scelidosaurus[39][40]

S. sp. (S. "arizonensis")

Valley of the Buttes

Silty Facies

UCMP 130056, scutes

A controversial thyreophoran, resembles the osteoderms of S. harrisonii.

Scutellosaurus[41][42][36]

Scutellosaurus lawleri
  • Paiute North 1
  • 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)
  • 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
  • TMM 43687-9, 16, 17, 22, 42, 50, 57, 75, 81, 96, 112, 114–116, 121–122, 124
  • TMM 45609-10, 11
  • TMM 45609-4, 6
  • TMM 45609-5, 7–9
  • TMM 43669-11
  • TMM 45608-1, 3
  • TMM 43647-7
  • TMM 43656-5
  • TMM 43670-5, 7–8

A basal thyreophoran, the most abundant dinosaur of the formation
Scutellosaurus

Theropoda[19][13][41]

Theropoda indeterminate
  • Utah Route 7 near St.George
  • Airhead West
  • Gold Spring General
  • Gold Spring Wash

Silty Facies
  • 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[13]

Pterosauria? Indeterminate
  • Utah Route 7 near St.George

Silty Facies
  • Teeth

Possible pterosaur teeth

Rhamphinion[19][43]

Rhamphinion jenkinsi[43]
  • 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[44]
  • Dinnebitodon amarali[44]
  • Dinnebitodon sp.
  • cf. Dinnebitodon sp.
  • Dinnebito Wash
  • Hummingbird Canyon
  • Gold Spring General

Silty Facies
  • MNA V3222 (Type, partial skull and associated postcrania); 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[45]

Dinnetherium nezorum
  • Gold Spring Quarry 1

Silty Facies

MNA V3221; MCZ 20870-20877

A mammaliaform, member of the family Megazostrodontidae

Haramiyidae[45]

Haramiyidae? indet.
  • Gold Spring Quarry 1

Silty Facies

MCZ 20879

Incertae sedis, a possible haramiyid

Kayentatherium[46]
  • Kayentatherium wellesi[46]
  • Kayentatherium sp.
  • Cf.Kayentatherium sp.
  • MCZ, The Landmark
  • Hummingbird Canyon
  • Gold Spring General
  • Gold Spring wash
  • Willow Spring General
  • Rock Head, general area

Silty Facies
  • MCZ 8811
  • 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.[47]
Kayentatherium

Morganucodon[45]

Morganucodon sp.
  • Gold Spring Quarry 1

Silty Facies

MCZ 20878

A mammaliaform, member of the family Morganucodontidae
Morganucodon

Oligokyphus[48]
  • Oligokyphus sp.
  • cf. Oligokyphus sp.
  • Gold Spring General
  • Gold Spring Quarry 1

Silty Facies
  • TMM 43687-86
  • > 42 specimens

A tritylodont, also present on coeval deposits from Asia and Europe.
Oligokyphus

Tritylodontidae[19][9]

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[49][50][51]
  • Anomoepus scambus
  • Anomoepus shingi
  • Anomoepus moabensis
  • Anomoepus 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[52][11]
  • Batrachopus isp.
  • Desert Tortoise tracksite

Tracks

Moving Tracks
  • Crocodrylomorphs

Pseudosuchia Footprints of the ichnofamily Batrachopodidae.

Characichnos[13]
  • Characichnos isp.
  • Utah Route 7 near St.George

Tracks

Moving Trails
  • Dinosaurs

Dinosaur Traces left while swimming

Dilophosauripus[53]
  • Dilophosauripus williamsi
  • Dilophosauripus isp.
  • Moenkopi Wash 4 tracksite
  • Moenave Road Tracksite
  • Goldtooth Spring tracksite
  • Cameron tracksite

Footprints

Moving Tracks

Theropod Footprints of the ichnofamily Grallatoridae.

Dinosauropedida[54][55]
  • Dinosauropedida ichnog. 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[49][56][52][51][57][58]
  • Eubrontes giganteus
  • Eubrontes 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

Theropod Footprints of the ichnofamily Grallatoridae. This type of tracks match with Dilophosaurus pes

Grallator[49][56][52][51]
  • Grallator tenuis
  • Grallator 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[49][52][59]
  • Kayentapus hopii[53]
  • Kayentapus soltykovensis
  • Kayentapus 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[49]
  • Limulidae indet.
  • Lisbon Valley Oilfield tracksite

Trackways

Moving Tracks
  • Limuloids
  • Insects?

Saltwater/Blackish-linked tracks with resemblance with extant Xiphosuran traces

Moyenisauropus[13]
  • Moyenisauropus isp.
  • Utah Route 7 near St.George

Footprints

Moving Tracks
  • Thyreophorans

Ornithischian Footprints of the ichnofamily Moyenisauropodidae.

Otozoum[60][61]
  • Otozoum 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[62]
  • Planolites 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.[63]
Example of Planolites fossil

Skolithos[62]
  • Skolithos 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[49]
  • Synapsidipedia ichnog. indeterminate
  • Lisbon Valley Oilfield tracksite

Tracks

Moving Tracks
  • Mammaliformes
  • Tritylodonts

Possible Synapsid Footprints, non assigned to any concrete ichnogenus

Taenidium[62]
  • Taenidium isp
  • Near St. George, Washington County

Unlined meniscate burrows

Fodinichnia

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[49][50][56]
  • Theropodipedia ichnog. 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[13]
  • Undichna 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[13]
  • Clathropteris sp.
  • Utah Route 7 near St.George
  • Leaflets

Affinities with Dipteridaceae inside Polypodiales.

Example of Clathropteris meniscioides specimen

Cycadidae[13]
  • Cycadidae Indet.
  • Utah Route 7 near St.George
  • Leaflets

Affinities with Cycadidae inside Cycadopsida.

Example of extant cycad, Encephalartos longifolius

Otozamites[13]
  • Otozamites sp.
  • Utah Route 7 near St.George
  • Leaflets

Affinities with Williamsoniaceae inside Bennettitales.

Pinopsida[13]
  • Pinopsida Indet.
  • Utah Route 7 near St.George
  • Leave Compressions
  • Isolated Cones

Affinities with Pinopsida inside Pinaceae.

Zamites[13]
  • Zamites 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

See also

Footnotes

  1. ↑ Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Jurassic, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. pp. 530–532. ISBN 0-520-24209-2.
  2. ↑ Marsh, A.D.; Rowe, T.; Simonetti, A.; Stockli, D.; Stockli, L. (2014). "The age of the Kayenta Formation of northeastern Arizona: overcoming the challenges of dating fossil bone". J. Vertebr. Paleontol. Prog. Abst. 34 (2): 178. Retrieved 19 November 2021.
  3. ↑ Steiner, M.; Tanner, L.H. (2014). "Magnetostratigraphy and paleopoles of the Kayenta Formation and the Tenney Canyon Tongue" (PDF). Volumina Jurassica. 12: 31–38. Retrieved 7 March 2022.
  4. 1 2 Marsh, Adam Douglas (2018). "Contextualizing the evolution of theropod dinosaurs in western North America using U-Pb geochronology of the Chinle Formation and Kayenta Formation on the Colorado Plateau". doi:10.26153/tsw/41876. {{cite journal}}: Cite journal requires |journal= (help)
  5. 1 2 3 Kietzke, K.K.; Lucas, S.G. (1995). "Ostracoda and Gastropoda from the Kayenta Formation (Lower Jurassic) of Arizona, U.S.A". Journal of Arizona–Nevada Academy of Science. 28 (1–2): 23–32. JSTOR 40024298. Retrieved 19 November 2021.
  6. 1 2 Lewis, G. E.; Irwin, J. H.; Wilson, R. F. (1961). "Age of the Glen Canyon Group (Triassic and Jurassic) on the Colorado Plateau". Geological Society of America Bulletin. 72 (9): 1437–1440. Bibcode:1961GSAB...72.1437L. doi:10.1130/0016-7606(1961)72[1437:AOTGCG]2.0.CO;2. Retrieved 2 January 2022.
  7. ↑ Harshbarger, J.W.; Repenning, C.A.; Irwin, J.H. (1957). "Stratigraphy of the uppermost Triassic and the Jurassic rocks of the Navajo Country" (PDF). United States Geological Survey Professional Paper. 291 (1): 1–74. Retrieved 2 January 2022.
  8. 1 2 3 4 5 6 7 Milner, A. R.; Kirkland, J. I.; Birthisel, T. A. (2006). "The geographic distribution and biostratigraphy of Late Triassic–Early Jurassic freshwater fish faunas of the southwestern United States". New Mexico Museum of Natural History and Science Bulletin. 37 (1): 522–529. Retrieved 19 November 2021.
  9. 1 2 3 4 5 6 7 8 9 10 Curtis, K.; Padian, K. (1999). "An Early Jurassic microvertebrate fauna from the Kayenta Formation of northeastern Arizona: microfaunal change across the Triassic‐Jurassic boundary". PaleoBios. 19 (1): 19–37.
  10. 1 2 Delsate, D.; Candoni, L. (2001). "Description de nouveaux morphotypes dentaires de Batomorphii toarciens (Jurassique inférieur) du Bassin de Paris: Archaeobatidae nov. fam". Bulletin-Société des Naturalistes Luxembourgeois. 102 (1): 131–143. Retrieved 19 November 2021.
  11. 1 2 Milner, A. R. C.; Birthisel, T. A.; Kirkland, J. I.; Breithaupt, B.H; Matthews, N. A.; Lockley, M. G.; Santucci, V. L.; Gibson, S. Z; DeBlieux, D. D.; Hurlbut, M.; Harris, J. D.; Olsen, P. E. (2011). "Tracking Early jurassic dinosaurs across southwestern Utah and the Triassic-Jurassic transition". Nevada State Museum Paleontological Papers. 1 (1): 1–107.
  12. 1 2 3 4 Gay, R. J.; Milner, A. R. (2015). "The first report of an archosaur from the Kayenta Formation of Washington County, Utah" (PDF). PeerJ PrePrints. 1048 (1): 1–21. Retrieved 19 November 2021.
  13. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Milner, A. R.; Gay, R. J.; Irmis, R.; Overkamp, F.; Santella, M. (2017). "New southwestern Utah paleontological locality from the Lower Jurassic Kayenta Formation reveals a diverse vertebrate fauna based on teeth and tracks [abs.]". Journal of Vertebrate Paleontology. 37 (1): 164.
  14. 1 2 3 Milner, A. R.; Kirkland, J. I. (2006). "Preliminary review of the early Jurassic (Hettangian) freshwater Lake Dixie fish fauna in the Whitmore Point Member, Moenave Formation in southwest Utah". New Mexico Museum of Natural History and Science Bulletin. 37 (1–2): 510–521. CiteSeerX 10.1.1.537.1492.
  15. ↑ Frederickson, Joseph A; Cifelli, Richard L. (2017). "New Cretaceous lungfishes (Dipnoi, Ceratodontidae) from western North America". Journal of Paleontology. 91 (1): 146–161. doi:10.1017/jpa.2016.131. S2CID 131962612.
  16. ↑ Jenkins, F. A.; Walsh, D. M. (1993). "An Early Jurassic caecilian with limbs". Nature. 365 (2–4): 246–250. Bibcode:1993Natur.365..246J. doi:10.1038/365246a0. S2CID 4342438. Retrieved 19 November 2021.
  17. ↑ Shubin, N. H.; Jenkins, F. A. (1995). "An early Jurassic jumping frog". Nature. 377 (6544): 49–52. Bibcode:1995Natur.377...49S. doi:10.1038/377049a0. S2CID 4308225. Retrieved 19 November 2021.
  18. 1 2 Simões, Tiago R.; Kinney-Broderick, Grace; E. Pierce, Stephanie (2022). "An exceptionally preserved Sphenodon-like sphenodontian reveals deep time conservation of the tuatara skeleton and ontogeny". Communications Biology. 5 (1): 195–208. doi:10.1038/s42003-022-03144-y. PMC 8894340. PMID 35241764. S2CID 247227560. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
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  22. ↑ Crompton, A. W.; Smith, K. K. (1980). Jacobs, L. (ed.). "A new genus and species from the Kayenta Formation (Late Triassic?) of Northern Arizona". Aspects of Vertebrate History. Museum of Northern Arizona Press. 34 (1): 193–217. Retrieved 19 November 2021.
  23. ↑ Clark, J. M.; Sues, Hans-Dieter (2002). "Two new species of basal crocodylomorphs and the status of the Sphenosuchia". Zoological Journal of the Linnean Society. 136 (1–6): 77−96. doi:10.1046/j.1096-3642.2002.00026.x. S2CID 83511047.
  24. ↑ Ősi, Attila (2014). "The evolution of jaw mechanism and dental function in heterodont crocodyliforms". Historical Biology. 26 (3): 279–414. doi:10.1080/08912963.2013.777533. hdl:10831/75192. S2CID 85707749. Retrieved 24 November 2021.
  25. ↑ Ruebenstahl, A. A.; Klein, M. D.; Yi, H.; Xu, X.; Clark, J. M. (2022). "Anatomy and relationships of the early diverging Crocodylomorphs Junggarsuchus sloani and Dibothrosuchus elaphros". The Anatomical Record. 305 (Special Issue): 2463–2556. doi:10.1002/ar.24949. PMC 9541040. PMID 35699105. S2CID 249645515.
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  27. 1 2 3 4 5 6 7 8 Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Jurassic, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. pp. 530–32. ISBN 0-520-24209-2.
  28. ↑ Tykoski, R.S. (1997). "A new ceratosaurid theropod from the Early Jurassic Kayenta Formation of Northern Arizona". Journal of Vertebrate Paleontology. 17 (3): 81–82.
  29. ↑ Rowe, T. (1989). "A new species of the theropod dinosaur Syntarsus from the Early Jurassic Kayenta Formation of Arizona" (PDF). Journal of Vertebrate Paleontology. 9 (2): 125–36. doi:10.1080/02724634.1989.10011748. Retrieved 19 November 2021.
  30. ↑ Bristowe, A.; M.A. Raath (2004). "A juvenile coelophysoid skull from the Early Jurassic of Zimbabwe, and the synonymy of Coelophysis and Syntarsus.(USA)". Palaeontologica Africana. 40 (40): 31–41.
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  49. 1 2 3 4 5 6 7 Lockley, M. G.; Hunt, A. P. (1995). Dinosaur Tracks and Other Fossil Footprints of the Western United States (2 ed.). USA: Columbia University Press. pp. 15–287. ISBN 9780231079273. Retrieved 2 January 2022.
  50. 1 2 Milner, A.R.C.; Birthisel, T. A.; Kirkland, J. I.; Breithaupt, B.H.; Matthews, N. A.; Lockley, M. G.; Santucci, V. L.; Gibson, S. Z.; DeBlieux, D. D.; Hurlbut, M.; Harris, J. D.; Olsen, P. E. (2011). "Tracking Early jurassic dinosaurs across southwestern Utah and the Triassic-Jurassic transition". Nevada State Museum Paleontological Papers. 1 (1): 1–107.
  51. 1 2 3 Miller, W. E.; Britt, B. B.; Stadtman, K. L. (1986). "Theropod and prosauropod trackways from the Moenave Formation of southwestern Utah". In D. D. Gillette (Ed.), First International Symposium on Dinosaur Tracks and Traces, Abstracts with Program. 21 (2): 36–48.
  52. 1 2 3 4 Lockey, M.; Milner, A.C.; Hamblin, D. (2006). "Dinosaur tracksites from the Kayenta Formation (Lower Jurassic),'. Desert Tortoise site,'Washington County, Utah". New Mexico Museum of Natural History and Science Bulletin. 37 (2): 269–275. Retrieved 2 January 2022.
  53. 1 2 Welles, S. P. (1971). "Dinosaur footprints from the Kayenta Formation of northern Arizona". Plateau. 44 (1): 27–38.
  54. ↑ Stokes, W. L.; Bruhn, A. F. (1960). "Dinosaur tracks from Zion National Park and Vicinity, Utah". Utah Academy Proceedings. 37 (2): 75–76.
  55. ↑ Barnes, F. A. (1997). "Canyon Country Dinosaur". Tracks and Trackers. 54 (1): 1–176.
  56. 1 2 3 Hamblin, A. H.; Lockley, M.G.; Milner, A.R.C. (2006). "More reports of theropod dinosaur tracksites from the Kayenta Formation (Lower Jurassic), Washington County, Utah: implications for describing the Springdale megatracksite". New Mexico Museum of Natural History and Science Bulletin. 37 (3): 276–281.
  57. ↑ Hamblin, A. H. (2006). Spectrum Tracksite—also known as the Grapevine Pass Wash Tracksite. California State University: Desert Studies Consortium and LSA Associates.
  58. ↑ Lockley, M. G.; Hunt, A. P.; Meyer, C. A.; Rainforth, E. C.; Schultz, R. J. (1998). "A survey of fossil footprint sites at Glen Canyon National Recreation Area (western USA): a case study in documentation of trace fossil resources at a national preserve". Ichnos. 5 (3): 177–211. doi:10.1080/10420949809386417.
  59. ↑ Hamblin, A. H.; Foster, J. R. (2001). "Ancient animal footprints and traces in the Grand Staircase-Escalante National Monument, south-central Utah". Utah Geological Association Publication. 28 (4): 1–12.
  60. ↑ Lockey, M.G.; Gierlinski, G.D. (2014). "A new Otozoum-dominated tracksite in the Glen Canyon Group (Jurassic) of eastern Utah". New Mexico Museum of Natural History and Science Bulletin. 62 (3): 211–214. Retrieved 3 January 2022.
  61. ↑ Lockley, M.G.; Matthews, N.; Breithaupt, B.H.; Gierlinski, G.; Cart, K.; Hunt-Foster, R. (2018). "Large Dinosaur Tracksites in the Lower Jurassic Kayenta Formation near Moab, Utah: implications for Paleoecology". Bull N M Mus Nat Hist Sci. 79 (4): 441–449. Retrieved 3 January 2022.
  62. 1 2 3 Difley, R.; Ekdale, A. A. (2006). "Trace fossils and paleoenvironments of the Early Jurassic Kayenta Formation, Washington County, Utah" (PDF). Making Tracks Across the Southwest. 6 (2): 49–51. Retrieved 2 January 2022.
  63. ↑ Keighley, D. G.; Pickerill, R. K (1995). "The ichnotaxa Palaeophycus and Planolites_ historical perspectives and recommendations". Ichnos. 3 (4). doi:10.1080/10420949509386400.

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