Wikipedia

Kayenta Formation

TheKayenta Formationis ageological formationin theGlen Canyon Groupthat is spread across theColorado Plateauarea of theUnited States,including northernArizona,northwestColorado,Nevada,andUtah.Originally suggested as beingSinemurian-Pliensbachian, but more recentdating of detrital zirconshas yielded a depositional age of 183.7 ± 2.7 Ma, thus a Pliensbachian-Toarcianage is more likely.[2]A previous depth work recovered a solid "Carixian" (Lower-Middle Pliensbachian) age from measurements done in theTenney 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 theToarcian Oceanic Anoxic Event.[4]This last age asignation also correlated the Toarcian Vulcanism on the westCordilleran Magmatic Arc,as the number of grains from this event correlate with the silt content in the sandstones of the upper layers.[4]

Kayenta Formation
Stratigraphic range:Sinemurian-Toarcian
~198.0–178.8Ma
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′N110°36′W/ 37.8°N 110.6°W/37.8; -110.6
CountryUnited States
ExtentnorthernArizona,northwestColorado,Nevada,andUtah[1]
Type section
Named forKayenta, Arizona
Kayenta Formation west of Tuba City, Arizona.

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 includeZion National Park,Capitol Reef National Park,theSan Rafael Swell,andCanyonlands National Park.

The Kayenta Formation frequently appears as a thinner dark broken layer belowNavajo Sandstoneand aboveWingate 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

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Southeast Utah

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Redbeds including the Kayenta Formation and theNavajo SandstoneinKolob Canyons,Zion National Park,Utah, USA
ThePermianthroughJurassicstratigraphy of theColorado Plateauarea of southeasternUtahthat makes up much of the famous prominent rock formations in protected areas such asCapitol Reef National ParkandCanyonlands National Park.From top to bottom: Rounded tan domes of theNavajo Sandstone,layered red Kayenta Formation, cliff-forming, vertically jointed, redWingate Sandstone,slope-forming, purplishChinle Formation,layered, lighter-redMoenkopi Formation,and white, layeredCutler Formationsandstone. Picture fromGlen Canyon National Recreation Area,Utah.

In most sections that include all threegeologic formationsof theGlen Canyongroup 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 beddedstrataof 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, alllenticular,uneven at their tops, and discontinuous within short distances. They suggest deposits made by shiftingstreamsof 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-roundedquartzgrains cemented bylimeandiron.The thicker beds are indefinitely cross bedded. The shales are essentiallyfine-grained,very thin sandstones that include limeconcretionsand balls of consolidatedmud.The limestone appears as solid gray-blue beds, a few inches to a few feet thick, and as lenses of limestoneconglomerate.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. InMoqui Canyonnear Red Cone Spring nearly 3 metres (10 ft) of Kayenta limestone conglomerate rests in a long meanderingvalleycut 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 fewripple marks,and incipient drainage channels were observed in the topmost bed of the Kayenta onRed 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 toerosionbefore 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

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The red and mauve Kayentasiltstonesandsandstonesthat form the slopes at base of theNavajo Sandstonecliffs 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) ofsedimenthere. Thesedimentary structuresshowing the channel andflood plaindeposits ofstreamsare well exposed on switchbacks below the tunnel in Pine Creek Canyon.

In the southeastern part of Zion National Park a stratum ofcross beddedsandstoneis 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 ofKanab,and it shows thatdesertconditions 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.

Fossilmudcracksattest to occasional seasonalclimate,and thinlimestonesandfossilized trailsofaquaticsnailsorwormsmark the existence ofpondsandlakes.The most interesting fossils, however, are thedinosaurtracks that are relatively common in Kayenta mudstone.

These vary in size, but all seem to be the tracks of three-toedreptilesthat 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 ofSenegalwith rainy summers and dry winters at the southern edge of a great desert. The influence of thedesertwas about to predominate, however, asNorth Americadrifted northward into the arid desert belt.

Glen Canyon

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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 andMoenave formation.Dinosaur tracks are fairly common in the siltstone, andfresh watermusselsandsnailsoccur but are rare. The Kayenta Formation is colored pale red and adds to the splendor of theVermilion Cliffs.It accumulated as deposits of rivers.

Fossils

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Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are insmall text;crossed outtaxa are discredited.

Invertebrates

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Genus Species Location Stratigraphic position Material Notes Images

Darwinula[5]

  • D. magna
  • D.sarytirmensis
  • Gold Spring Quarry 1

Base of the "typical facies"

Valves

A freshwater (lacustrine or fluvial) ostracod, type member of the familyDarwinulidae.Kayenta specimens have a distinctive columnar calcitic layer. The Kayenta fauna is similar to the Sinemurian faunas of theToutunhe Formationof Xin gian g, China.

Liratina[5]

  • L. sp.
  • Gold Spring Quarry 1

Base of the "typical facies"

Single shell

A freshwater (lacustrine or fluvial) snail, incertae sedis insideMesogastropoda.Differs considerably from the species from the Upper JurassicMorrison Formation,Liratinajurassicum

Lymnaea[6]

  • L. hopii
  • Colorado Plateau

Base of the "typical facies"

Shells

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

Scabriculocypris[5]

S. n. sp

  • Gold Spring Quarry 1

Base of the "typical facies"

Valves

A freshwater (lacustrine or fluvial) ostracod, incertae sedis insideCypridacea.Differs from all other described species of the genus in being more elongate and from most in being spinose.

Unio[7]

  • U. dumblei
  • U. dockumensis
  • U. iridoides
  • South of Moab

Base of the "typical facies"

Shells

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

Valvata[6]

  • V. gregorii
  • Colorado Plateau

Base of the "typical facies"

Shells

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

Fishes

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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 topreservation bias.[8]Another aspect that can explain the lack of fish fossils found is the use of different research techniques than used on theChinle Formation.[8]

Chondrichthyes

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Taxon Species Location Stratigraphic position Material Notes Images

Hybodontoidea[9]

Indeterminate

  • Shonto Trading Post, Segi Canyon
  • Ward Terrace

Base of the "typical facies"

UCMP136104, 136105 + ten uncatalogued specimens, teeth

A freshwater (lacustrine or fluvial) non-neoselachian shark, incertae sedis insideHybodontoidea.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]

Indeterminate

Gold Spring Quarry 1

Base of the "typical facies"

Isolated Tooth

A freshwater (lacustrine or fluvial)toarcibatid.Related originally withMicropristisorLibanopristis,and stated to be reworked from younger Cretaceous deposits, was found due to its asymmetrical cusp to fit within the definition ofToarcibatis,being more likely to be native of the formation.[10]

Actinopterygii

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Taxon Species Location Stratigraphic position Material Notes Images

Lophionotus[11]

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)semionotidsemionotiform.

"Palaeoniscidae"[8][12][13]

Indeterminate

  • Utah Route 7 near St.George
  • Warner Valley

Base of the "typical facies"

  • Isolated Ganoid Scales& Teeth

A freshwater (lacustrine or fluvial)palaeoniscidpalaeonisciform.

Semionotidae[8][12][13]

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)semionotidsemionotiform,probably related to the genusSemionotus.Semionotiformes are the only properly identified bony fishes from the formation, including a large specimen exposed at the Dan O’Laurie Museum.[8]

Semionotusis probably related to the Kayenta Seminotiformes

Sarcopterygii

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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Ceratodus[8][14]

C. stewarti

  • Goblin Valley State Park

Middle “Silty Facies”

  • OMNH69332, left pterygopalatine plate

A freshwater (lacustrine or fluvial)ceratodontiddipnomorph(lungfish).

Ceratodus

Coelacanthidae[14][12]

Indeterminate

  • Tsegi Canyon
  • Warner Valley

Base of the "typical facies"

  • Isolated remains & Scales

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

Potamoceratodus[15]

P. guentheri

  • Tsegi Canyon?
  • Little Colorado River Valley on Ward Terrace

Middle “Silty Facies”

  • Single dipnoan tooth plate (MCZ13865)

A freshwater (lacustrine or fluvial)ceratodontiddipnomorph(lungfish). Was described asC. felchi,know from the Upper JurassicMorrison Formation.Other dipnoan specimens have been cited but never described.[14]

Amphibia

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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Anura[9]

Indeterminate

Gold Spring Quarry 1

Silty Facies Member

  • MCZ 9019, distal humerus
  • MCZ 9020–24, ilia

An early frog, incertae sedis relationships

Eocaecilia[16]

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 earliestgymnophionansas a close relative of caecilians

Eocaecilia

Lissamphibia[9]

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]

P. bitis

Gold Spring Quarry 1

Silty Facies Member

MNAV 8725, associated desarticulated remains of 2 individuals; referred MCZ 9324 A & MCZ 9323 A

An early frog, probably related toNotobatrachidae

Prosalirus

Urodela[9]

Indeterminate

Gold Spring Quarry 1

Silty Facies Member

MCZ 9017, 9018, atlas vertebrae

A possible stem-salamander, incertae sedis insideUrodela.The oldest record of an urodelan from North America

Reptilia

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Rhynchocephalia

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Taxon Species Location Stratigraphic position Material Notes Images

Navajosphenodon[18]

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 ofSphenodontinae.The skeleton ofN. sanishows a large number of similarities with the modern tuataraS. punctatus,clustering them closely together in the morphospace of sphenodontians and early lepidosaurs.[18]

Navajosphenodon

Rhynchocephalia[19]

Indeterminate

Airhead West

Silty Facies

Uncertain Fragments

Rhynchocephalians of uncertain assignment

Sphenodontia[9]

Indeterminate

Gold Spring Quarry 1

Silty Facies

MCZ 9036 through 9040, jaw fragments

An indeterminate sphenodont

Testudinatans

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Genus / taxon Species Location Stratigraphic position Material Notes Images

Cryptodira[9]

Indeterminate

Red Knob

Silty Facies

Uncertain fragments

Cryptodirans of uncertain assignment

Kayentachelys[20]

  • 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...

Amesochelydian

Kayentachelys

Testudinata[9][19]

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

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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Calsoyasuchus[21]

C. valliceps

Adeii Eechii Cliffs, Navajo Nation

Silty Facies

TMM 43631-1 (holotype), partial skull

A terrestrial member of theHsisosuchidae.Alternatively can be a relative ofThalattosuchia

Crocodylomorpha[9][13]

  • "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, probablyEopneumatosuchus
  • UCMP 136102, fragment of lower jaw

Indeterminate crocodylomorphs. Includes a new taxon with skull similar toOrthosuchusstormbergi.

Eopneumatosuchus[22]

E. colberti

Blue layer, Silty Facies

Silty Facies

  • MNA P1.2460, partial skull
  • Isolated Jaw

An early terrestrial or semiterrestrial protosuchid crocodylomorph

Kayentasuchus[23][12]

K. walkeri

  • Warner Valley
  • Willow Springs 13

Silty Facies

  • UCMP 131830, nearly complete skeleton
  • UMNHVP 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 theCretaceousEdentosuchus tienshanensis,one that has been referred to informally as "Gomphosuchus"(including UCMP 97638 and UCMP 125871) and another unnamed taxon (including UCMP 130082).[25]Previously considered one taxon (the 'Kayenta form') in older literature.[26]

Dinosaurs

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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]

Ornithischians
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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Heterodontosauridae[28][29]

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[28]

A heterodontosaurid of uncertain placement. Appears to have been an insectivore downsized to a degree not seen before among early dinosaurs.

Ornithischia[30][13][31]

  • 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 toDilophosauruswetherilli.[30]The femur resembles that of the early neornithischianLesothosaurus.[31]

Scelidosaurus[32][33]

S.sp. (S."arizonensis" )

Valley of the Buttes

Silty Facies

UCMP 130056, scutes

A controversial thyreophoran, resembles the osteoderms ofS. harrisonii.

Scutellosaurus[34][35][30]

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
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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Sarahsaurus[36][37]

S. 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 familyMassospondylidae.Originally thought to beMassospondylus[27]

Sarahsaurus
Theropods
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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Coelophysidae[38]

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

Acoelophysidneotheropod.

Coelophysis[39][40]

C. kayentakatae

  • Rock Head (Bowl Area)
  • Gold Spring Wash
  • Shake-N-Bake

Silty Facies

  • MNI; MNA V2623
  • TMM 43669-3
  • MNA V100, V140

Acoelophysidneotheropod. Referred to asSyntarsusby Weishampelet al.[27]Formerly known asMegapnosaurus.

Coelophysis kayentakatae

Dilophosaurus[41][42]

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 familyDilophosauridae.Dilophosaurusis 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.[42]

Dilophosaurus

Kayentavenator[43]

K. elysiae[43]

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 toM. kayentakataeby Rowe.

Kayentavenator

Theropoda[19][13][34]

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[44]
  • Isolated Teeth (+50)
  • TMM 43669-10
  • TMM 43687-10, 58, 60, 71, 85, 91, 98, 102, 105, 119

Incertae sediswithin Theropoda, probably Neotheropoda

Pterosauria

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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Pterosauria[13]

Indeterminate

  • Utah Route 7 near St.George

Silty Facies

  • Teeth

Possible pterosaur teeth

Rhamphinion[19][45]

R. jenkinsi[45]

  • 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 familyDimorphodontidae.Was originally classified as a "rhamphorhynchoid", represents the only major pterosaur identified from the formation and one of the oldest from North America.

Synapsida

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Genus / Taxon Species Location Stratigraphic position Material Notes Images

Dinnebitodon[46]

  • D. amarali[46]
  • 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[47]

D. nezorum

  • Gold Spring Quarry 1

Silty Facies

  • MNA V3221; MCZ 20870-20877

A mammaliaform, member of the familyMegazostrodontidae

Haramiyidae[47]

Indeterminate

  • Gold Spring Quarry 1

Silty Facies

  • MCZ 20879

Incertae sedis, a possible haramiyid

Kayentatherium[48]

  • K. wellesi[48]
  • 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.[49]

Kayentatherium

Morganucodon[47]

M. sp.

  • Gold Spring Quarry 1

Silty Facies

  • MCZ 20878

A mammaliaform, member of the familyMorganucodontidae

Morganucodon

Oligokyphus[50]

  • 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[19][9]

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

edit
Genus Species Location Material Type Origin Notes Images

Anomoepus[51][52][53]

  • 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 ichnofamilyMoyenisauropodidae.

Batrachopus[54][11]

  • B. isp.
  • Desert Tortoise tracksite

Tracks

Moving Tracks

  • Crocodrylomorphs

Pseudosuchia Footprints of the ichnofamilyBatrachopodidae.

Characichnos[13]

  • C. isp.
  • Utah Route 7 near St.George

Tracks

Moving Trails

  • Dinosaurs

Dinosaur Traces left while swimming

Dilophosauripus[55]

  • D. williamsi
  • D. isp.
  • Moenkopi Wash 4 tracksite
  • Moenave Road Tracksite
  • Goldtooth Spring tracksite
  • Cameron tracksite

Footprints

Moving Tracks

Theropod Footprints of the ichnofamilyGrallatoridae.

Dinosauropedida[56][57]

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[51][58][54][53][59][60]

  • 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

Theropod Footprints of the ichnofamilyGrallatoridae.This type of tracks match withDilophosauruspes

Grallator[51][58][54][53]

  • 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 ichnofamilyGrallatoridae.Likely from smaller local theropods

Kayentapus[51][54][61]

  • K. hopii[55]
  • 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 ichnofamilyGrallatoridae.

Limulidae[51]

Indeterminate
  • Lisbon Valley Oilfield tracksite

Trackways

Moving Tracks

  • Limuloids
  • Insects?

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

Moyenisauropus[13]

  • M. isp.
  • Utah Route 7 near St.George

Footprints

Moving Tracks

  • Thyreophorans

Ornithischian Footprints of the ichnofamilyMoyenisauropodidae.

Otozoum[62][63]

  • O. isp.
  • Flat Iron Mesa tracksite
  • Poison Spider Mesa tracksite

Footprints

Moving Tracks

  • Sauropodomorphs

Theropod Footprints of the ichnofamilyOtozoidae.Includes tracks referable to bipedal Sauropodomorphs

Planolites[64]

  • 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 ofPalaeophycus.[65]

Example ofPlanolitesfossil

Skolithos[64]

  • 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 theDomichnionof a suspension-feeding Worm orPhoronidan,with certainSkolithosrepresenting entrance shafts to more complicated burrows.

Skolithos ichnofosil reconstruction, with possible fauna associated

Synapsidipedia[51]

Indeterminate
  • Lisbon Valley Oilfield tracksite

Tracks

Moving Tracks

  • Mammaliformes
  • Tritylodonts

Possible Synapsid Footprints, non assigned to any concrete ichnogenus

Taenidium[64]

  • T. isp
  • Near St. George, Washington County

Unlined meniscate burrows

Fodinichnia

Saltwater/Blackish burrow-like ichnofossils.Taenidiumis 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[51][52][58]

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]

  • 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

edit
Genus Species Stratigraphic position Material Notes Images

Clathropteris[13]

  • C. sp.
  • Utah Route 7 near St.George
  • Leaflets

Affinities withDipteridaceaeinsidePolypodiales.

Example ofClathropterismeniscioidesspecimen

Cycadidae[13]

Indeterminate
  • Utah Route 7 near St.George
  • Leaflets

Affinities withCycadidaeinsideCycadopsida.

Example of extant cycad,Encephalartoslongifolius

Otozamites[13]

  • O. sp.
  • Utah Route 7 near St.George
  • Leaflets

Affinities withWilliamsoniaceaeinsideBennettitales.

Pinopsida[13]

Indeterminate
  • Utah Route 7 near St.George
  • Leave Compressions
  • Isolated Cones

Affinities withPinopsidainsidePinaceae.

Zamites[13]

  • Z. powellii
  • Utah Route 7 near St.George
  • Leaflets

A member ofWilliamsoniaceaeinsideBennettitales.It has been interpreted as a cycad in the familyCycadaceaeor aBennettitaleanplant, and also a late surviving member ofNoeggerathiales.

Example ofZamitesmandelslohi specimen

See also

edit

Footnotes

edit
  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.ISBN0-520-24209-2.
  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.Retrieved19 November2021.
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  5. ^abcKietzke, 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.JSTOR40024298.Retrieved19 November2021.
  6. ^abLewis, 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.Retrieved2 January2022.
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  65. ^Keighley, D. G.; Pickerill, R. K (1995)."The ichnotaxa Palaeophycus and Planolites_ historical perspectives and recommendations".Ichnos.3(4).doi:10.1080/10420949509386400.

References

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