The Chinle Formation is an extensive geological unit in the southwestern United States, preserving a very diverse fauna of Late Triassic (primarily Norian-age) animals and plants. This is a list of fossilized organisms recovered from the formation.

Amniotes

Archosauromorphs

Phytosaurs

Phytosaurs of the Chinle Formation
GenusSpeciesStateMemberAbundanceNotesImages
Leptosuchus[1]L. crosbiensis[1]A basal leptosuchomorph related to Smilosuchus.
Machaeroprosopus[2]M. buceros[2]
  • Arizona[2]
  • New Mexico
A mystriosuchin. The type species of Machaeroprosopus.
M. jablonskiae[3]
  • Arizona
  • Sonsela
Partial skullAn early-diverging mystriosuchin.[3]
M. mccauleyi[2]A mystriosuchin.
M. pristinus[2]A mystriosuchin. The type species of "Pseudopalatus", which is now considered a synonym of Machaeroprosopus.
cf. Paleorhinus[4]Indeterminate[4]
  • Mesa Redondo[4]
Pravusuchus[5]P. hortus
  • Arizona
  • Sonsela
Three skulls.A basal leptosuchomorph closely related to Mystriosuchini[5][6] or Nicrosaurus.[7]
Protome[8]P. batalaria
  • Arizona
  • Sonsela
Partial skull and jaw.A phytosaur originally described as a juvenile Leptosuchus, but probably an unrelated non-leptosuchomorph[8] or mystriosuchin.[7]
Redondasaurus[9]R. gregorii[9]
  • "Siltstone" / Rock Point[10]
  • Petrified Forest[10]
  • Church Rock[10]
A large late-surviving mystriosuchin. Either a close relative of Machaeroprosopus (formerly known as Pseudopalatus),[11] or a subgenus of that taxon.[10][6][7]
Smilosuchus[10]S. adamanensis[1]Known from a single skullPreviously referred to Leptosuchus, actually referable to Smilosuchus.[5]
S. gregorii
  • Arizona
  • Sonsela
  • Blue Mesa
  • Mesa Redondo
Known from a handful of skulls.A basal leptosuchomorph, split off from Leptosuchus.
S. lithodendrorum[5]
  • Arizona
  • Blue Mesa
Known from only one skull.Previously considered synonymous with S. adamanensis.

Suchians

Suchians of the Chinle Formation
GenusSpeciesStateMemberAbundanceNotesImages
Acaenasuchus[12]A. geoffreyi[12]Known from a handful of isolated osteoderms.[12]A controversial suchian based primarily on osteoderms. Some paleontologists have considered Acaenasuchus to be juvenile Desmatosuchus haplocerus scutes, while others considered it a separate genus of small aetosaurs.[12] In 2020 it was redescribed as an aetosauriform related to, but not within, Aetosauria. It is also related to Revueltosaurus (also from the Chinle) and the armored reptile Euscolosuchus from Virginia.[13]
AdamanasuchusA. eisenhardtae
  • Arizona
  • Blue Mesa
Osteoderms and skull and postcranial fragments.A basal desmatosuchine aetosaur related to Calyptosuchus and Scutarx.[14]
Calyptosuchus[15]C. wellesi[16]Common, although "non-armor material is comparatively rare".[16]A basal desmatosuchine aetosaur originally considered a species of Stagonolepis.
Desmatosuchus[17]D. spurensis[18]Numerous osteoderms and other skeletal materialA large desmatosuchin aetosaur which was fairly common in the lower part of the Chinle Formation. Prior to 2008, fossils of D. spurensis were listed as the species D. haplocerus, until it was determined that D. haplocerus was a species name originally based on undiagnostic fossils.[14]
D. smalli[19]A single lateral osteoderm.A desmatosuchin aetosaur which is very rare in the Chinle Formation. One of the youngest known occurrences of the genus Desmatosuchus.[14]
EffigiaE. okeeffeae
  • New Mexico
  • "Siltstone"
A six-foot-long shuvosaurid from the Coelophysis quarry of Ghost Ranch.
Eosphorosuchus[20]E. lacrimosa
  • New Mexico
  • "Siltstone" / Rock Point
Partial skull, a cervical vertebra, pubes, left hindlimb and three osteodermsAn early crocodylomorph from the Coelophysis quarry of Ghost Ranch. It had a short and reinforced facial region, likely adapted for powerful bites.
Hesperosuchus[21]H. agilis[21]An early-diverging crocodylomorph
Kryphioparma[22]K. caerula
  • Arizona
  • Blue Mesa
Osteoderms.An aetosaur described in 2023, probably related to other typothoracines.[22]
Labrujasuchus[23]L. expectatus
  • New Mexico
  • Petrified Forest
Partial skeleton and other postcraniaA shuvosaurid from the Hayden Quarry of Ghost Ranch.[23]
Paratypothorax[24]P. andressorum[24]
  • Blue Mesa
  • Sonsela
OsteodermsA significant number of researchers feel that the North American material referred to the German Paratypothorax species P. andressorum by Hunt and Lucas in 1992 is actually distinct.[24]
Indeterminate[25]Osteoderms and minor postcranial fragments.A paratypothoracin typothoracine aetosaur known from isolated material similar to more complete specimens from Germany.[26]
Parrishia[27]P. mccreai[27]A dubious genus of crocodylomorph, known from isolated vertebrae
Poposaurus[28]P. gracilis[28]A poposaurid pseudosuchian.
Postosuchus[29]P. kirkpatricki[29]A rauisuchid. "Rauisuchian" fossils from the Chinle are commonly referred to Postosuchus, under the assumption that it was the only large rauisuchian in the formation. The recognition of Vivaron indicates that this is not the case. Less ambiguous Postosuchus fossils are known from Texas.
Revueltosaurus[30]R. callenderi[31]
  • Petrified Forest[31]
A suchian with extensive armor and adaptations for herbivory, including teeth initially mistaken as belonging to ornithischian dinosaurs. It was probably an aetosauriform (aetosaur relative).
R. hunti[32]
RioarribasuchusR. chamaensis
  • Petrified Forest[33]
  • Sonsela
Osteoderms and possible ankle and vertebrae remains.A late-surviving paratypothoracin typothoracine aetosaur. Originally referred to Desmatosuchus, but later reinterpreted as a relative of Paratypothorax based on a phylogenetic analysis performed on the remains by Parker in 2003.[33] New genus names were erected independently by Parker (coining the name Heliocanthus) and Lucas et al. (coining the name Rioarribasuchus), prompting an investigation into reports of unethical taxonomic claim-jumping by the latter party.
Saurosuchus[34]Indeterminate[34]Jaw fragment.Identified from a fossil which has been reinterpreted as an indeterminate "rauisuchian".
Scutarx[14]S. deltatylus[14]Four partial skeletons including skull fragments.A large basal desmatosuchine aetosaur based on fossils originally referred to "Stagonolepis" (=Calyptosuchus) wellesi, a close relative. Fossils of Scutarx represent the highest stratigraphic occurrence of Stagonolepis-like aetosaurs in Petrified Forest National Park.
Shuvosaurus[35]S. inexpectatus[35]Following a rediagnosis of the genus and species, only shuvosaurid fossils from the Cooper Canyon Formation are reliably identifiable as Shuvosaurus itself.[36]
Sonselasuchus[37]S. cedrus[37]More than 950 disassociated and non-articulated bones belonging to at least 36 individuals[37]A shuvosaurid that may have shifted from quadrupedal to bipedal locomotion through ontogeny.[37]
StenomytiS. huangae
  • Colorado
  • "Red siltstone"
Partial skeleton including a well-preserved skull.A small aetosaurine aetosaur similar to Aetosaurus.
Typothorax[38]T. coccinarum[38]Common in the Owl Rock and Petrified Forest Members.[38]A large, wide-bodied typothoracine aetosaur abundant throughout the Chinle Formation. Almost all of the known Chinle Typothorax fossils are isolated whole or fragmentary osteoderms.[38]
Tecovasuchus[22]T. chatterjeei
  • Arizona
  • Blue Mesa
Osteoderms.A paratypothoracin aetosaur, previously thought to be more widespread in the formation.[22]
Vivaron[39]V. haydeni[39]
  • Petrified Forest[39]
Skull fragments and hip bonesA large rauisuchid from the Hayden Quarry of Ghost Ranch, similar to Postosuchus.

Ornithodirans

"Prosauropod" tracks are present in the Redonda, Sloan Canyon, and Sheep Pen Sandstone formations, though these geological units are typically regarded as part of the Dockum Group rather than the Chinle Formation. Prosauropod tracks might be present in the Rock Point Formation as well. Geographically, the tracks are present in New Mexico.[40]

Theropod tracks have been found in Utah and New Mexico recovered from the Redonda, Sloan Canyon, and Sheep Pen Sandstone formations.[40] Indeterminate theropod remains are present throughout unambiguous strata of the Chinle Formation, including the Petrified Forest, Bluewater Creek, and Rock Point members of New Mexico.[40]

Ornithodirans of the Chinle Formation
GenusSpeciesStateMemberAbundanceNotesImages
Camposaurus[40]C. arizonensis[40]
  • Bluewater Creek Formation[40] (or Blue Mesa)
A coelophysine coelophysid from the Placerias Quarry.
Chindesaurus[40]C. bryansmalli[40]
  • Petrified Forest[40]
A large saurischian with similarities to herrerasaurids and Tawa hallae.
Coelophysis[40]C. bauri
  • "Siltstone"[41]
  • Petrified Forest
A coelophysid. Though originally based on rare fragments, in the 1940s numerous skeletons of C. bauri were discovered in a bonebed at Ghost Ranch in New Mexico
C. sp.[42]
  • Petrified Forest[42]
Originally assigned to C. bauri, but likely a different taxon.[42]
C. longicollis[40]
  • Petrified Forest[40]
Now considered a junior synonym of C. bauri.
C. willistoni
  • Petrified Forest[40]
Now considered a junior synonym of C. bauri.
DromomeronD. romeri
  • Arizona
  • Colorado
  • New Mexico
  • Petrified Forest (Hayden Quarry #3)
  • Owl Rock
  • "Red siltstone"
A lagerpetid pterosauromorph found at various Ghost Ranch quarries and elsewhere in the Chinle Formation.
DaemonosaurusD. chauliodus
  • New Mexico
  • "Siltstone"
Skull and neck vertebrae fragmentsA saurischian from the Coelophysis Quarry. with a short skull and enlarged teeth.
Eotephradactylus[43]E. mcintireae
  • Arizona
  • Owl Rock
Partial mandible, teeth, and wing finger boneAn early-diverging pterosaur
EucoelophysisE. baldwini
  • Petrified Forest[40]
A silesaurid dinosauriform closely related to the Polish genus Silesaurus.[44]
Kwanasaurus[45]K. williamparkeri
  • Colorado
  • "Red siltstone"
A silesaurid dinosauriform with adaptations for herbivory.
Ptychotherates[46]P. bucculentus
  • New Mexico
  • "Siltstone"
A single partial skullA short-skulled saurischian from the Coelophysis Quarry. Likely related to Chindesaurus, Daemonosaurus, and Tawa.
TawaT. hallae
  • New Mexico
  • Petrified Forest (Hayden Quarry)
A saurischian showing a mosaic of features similar to neotheropods and herrerasaurids.

Other archosauromorphs

Non-crurotarsan archosauromorphs of the Chinle Formation
GenusSpeciesStateMemberAbundanceNotesImages
AkidostropheusA. oligos
  • Arizona
Cervical, dorsal, and caudal vertebraeA tanystropheid archosauromorph bearing elongated spikes on the vertebral neural spines[47]
Crosbysaurus[48]C. harrisae[48]TeethAn archosauriform represented only by teeth.[48] It is treated as indeterminate archosauriform remains by Irmis in 2005.[48] It was originally thought to be an ornithischian dinosaur.
Doswellia[49]cf. D. kaltenbachi
  • Arizona
Osteoderms, vertebrae, rib and hip fragments.A doswelliid archosauriform.
Puercosuchus[50]P. traverorum
  • Arizona
  • Blue Mesa
Two monodominant bonebeds.A carnivorous malerisaurine azendohsaurid archosauromorph.
Rugarhynchos[51]R. sixmilensis
  • New Mexico
  • Bluewater Creek
Skull and postcranial fragments.A doswelliid archosauriform. Originally described as a species of Doswellia,[52] but subsequently transferred to a separate genus.
Syntomiprosopus[53]S. sucherorum
  • Arizona
Two to four individuals from a single quarry.[53]A short-faced archosauriform from the Placerias / Downs' Quarry. Possibly an unusual early-diverging crocodylomorph. Appears convergent with some Late Cretaceous notosuchians.[53]
Tanystropheidae[54]Indeterminate
  • New Mexico
  • Petrified Forest
VertebraeModerately-sized tanystropheid vertebrae from the Hayden Quarry, likely representing a new taxon closely related to Langobardisaurus and Tanytrachelos.[54]
cf. Tanystropheus[47]Indeterminate
  • Arizona
  • Blue Mesa
Cervical vertebraeTanystropheid neck vertebrae similar to Tanystropheus, but much smaller and later in time than any other Tanystropheus fossils.[47]
Tanytrachelos[55]Indeterminate[55] / T. ahynis[54]
  • New Mexico
  • Arizona[55]
  • Petrified Forest
  • Mesa Redondo[55]
Cervical rib,[55] calcaneum, etc.A small tanystropheid represented by several hundred fossil specimens.
Tecovasaurus[56]T. murryi[56]An unknown amniote represented by scattered teeth formerly believed to be from an ornithischian dinosaur.[56] Later discoveries of similar teeth in pseudosuchians meant that these could no longer be regarded as anything more specific than some kind of archosauriform.[56]
Trilophosaurus[57]T. buettneri[58]A trilophosaurid.
T. dornorum[59]A trilophosaurid.
T. jacobsi[60]A trilophosaurid.
T. phasmalophos[61]
  • Arizona
  • Sonsela
A late-surviving trilophosaurid.
Vancleavea[62]V. campi[62]
  • Arizona[62]
  • New Mexico
A strange aquatic carnivorous archosauriform, represented by both articulated skeletons and scattered elements like osteoderms and vertebrae.[62]

Other reptiles

Other reptiles of the Chinle Formation
GenusSpeciesStateMemberAbundanceNotesImages
Acallosuchus[64]A. rectori[64]Known only from a partial skull.[64]A strange neodiapsid whose bones were heavily ornamented "with subtriangular knobs... running the length of the bones." Even these ornamentations were ornamented "with additional grooves." It is too bizarre to be currently classified as anything more than a probable diapsid.[64]
Ancistronychus[65]A. paradoxus
  • Arizona
  • Sonsela
Manual unguals (hand claws).A drepanosaur related to Drepanosaurus.
Avicranium[66]A. renestoi
  • New Mexico
  • "Siltstone"
Skull and neck vertebrae.A drepanosaur with a toothless skull and a flexible neck owing to the heterocoelous (saddle-shaped) articular surfaces of the vertebral centrae. The neural spines are anteroposteriorly short and strongly anterodorsally inclined. These features closely resemble those of Drepanosaurus.
cf. Chinlechelys.[43]cf. C. tenertesta
  • Arizona
  • Owl Rock
Parts of carapaces, cervical osteoderms, a skull roof fragment, left pelvic girdle, a caudal vertebra, a possible squamosalA terrestrial testudinate (shelled stem-turtle).
Colognathus[67]C. obscurus[67]Known only from a jaw fragment and some isolated teeth.[67]Originally believed to be a fish, Colognathus was a strange amniote with distinctive fluted teeth.[67]
DolabrosaurusD. aquatilis
  • New Mexico
  • Petrified Forest
Articulated vertebral and limb material.A drepanosaur.
Drepanosaurus[68]D. unguicaudatus
  • New Mexico
  • Petrified Forest
A drepanosaur.
Fabanychus[69]F. monos
  • Arizona
  • Sonsela
A drepanosaur.
Microzemiotes[70]M. sonselaensis
  • Arizona
  • Sonsela
Partial left dentary with three teethA diapsid reptile of uncertain affinities.
Palacrodon[71]P. parkeri[71]
  • Arizona
  • Blue Mesa
Jaw fragments.A diapsid reptile of uncertain phylogenetic placement with unusual broadened teeth. More complete fossils of this genus from the Fremouw Formation of Antarctica suggest that it was an arboreal saurian.[72]
Skybalonyx[73]S. skapter
  • Arizona
  • Blue Mesa
Manual unguals (hand claws).A drepanosaur which likely had a burrowing lifestyle.
Uatchitodon[74]U. schneideri[75]Known in Chinle from only a single tooth. The presence of venom channels is consistent with other known Uatchitodon specimens, although the Chinle specimen's channels are unique in being "completely enclosed under the surface of the crown."[76]A reptile of unknown affinities, probably a carnivorous archosauromorph with venomous capabilities.
Whitakersaurus[77]W. bermani
  • New Mexico
  • "Siltstone"
A rhynchocephalian found at Ghost Ranch.
Leptopleuronine indet.Indeterminate
  • Utah
  • Owl Rock
An incomplete skull (specimen MNA V9953)[78]Inteterminate leptopleurine procolophonids.
  • Arizona
  • Owl Rock
Two skulls (specimens MCZ 9312 and 9313)[79]
Sphenodontia sp.[43]Indeterminate
  • Arizona
  • Owl Rock
A dentary.An indeterminate rhynchocephalian.

Synapsids

Synapsids of the Chinle Formation
GenusSpeciesStateMemberAbundanceNotesImages
Kataigidodon[80]K. venetus
  • Arizona
  • Blue Mesa
Partial dentaries.A non-mammalian eucynodont.
Kraterokheirodon[81]K. colberti[81]
  • Petrified Forest[81]
  • Blue Mesa or Mesa Redondo[81]
Known only from two teeth.[81]A possible cynodont. Although they share some similarities with cynodont teeth, the teeth of Kraterokheirodon are very distinctive and can't be confidently referred to a known amniote group.[81]
Placerias[82]P. hesternus[82]Known from several hundred remains, but very rare outside of the highly concentrated Placerias Quarry bonebed.[82]A placeriine stahleckeriid dicynodont.

Amphibians

Amphibians of the Chinle Formation
GenusSpeciesStateMemberAbundanceNotesImages
Apachesaurus[83]A. gregorii[83]Common in the Owl Rock and Petrified forest members.[83] Blue Mesa remains are fragmentary.[83]A metoposaurid temnospondyl which is a junior synonym of Anaschisma
Anaschisma[84][85]A. browni[86][85]A. browni is "possibly the most common tetrapod fossil in the lower Chinle", although its presence in the upper Chinle is "unclear".[86]A metoposaurid temnospondyl. Koskinonodon was erected for the species "Buettneria" perfecta when it was discovered that the latter genus was preoccupied. Gee et al., 2017 then synonymised it with Anaschisma.[84][85]
Chinlestegophis[87]C. jenkinsi
  • Colorado
  • "Red siltstone"
A temnospondyl in the group Stereospondyli, related to Rileymillerus from the Dockum Group of Texas. Originally interpreted as a stem-caecilian,[87] though others have disputed this finding.
Funcusvermis[88]F. gilmorei
  • Arizona
  • Blue Mesa
Numerous jaw fragments, as well as a referred maxillopalatine, vertebra, and femurA stem-caecilian
Salientia indet.[89]Indeterminate
  • Arizona
  • Sonsela Member
  • Blue Mesa Member
Five bones: four ilia and a partial maxilla.A stem-group frog. Might be more closely related to crown-group frogs (anurans) than to Early Triassic taxa Triadobatrachus and Czatkobatrachus.

Cartilaginous fish

Chondrichthyans of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotesImages
Acrodus[90]Indeterminate[90]Only a single tooth is known.[90]A hybodontiform shark.
Lonchidion[92]L. humblei[92]A hybodontiform shark. Lonchidion remains are common throughout the Carnian microvertebrate sites of the American southwest.[92]
PalaeoxyrisP. humblei[93]
  • Arizona
  • Blue Mesa
Several specimensAn egg capsule of a freshwater hybodont shark.
"Phoebodus"[94]Indeterminate[94]Only a single specimen has been recovered from the formation.[94]Triassic records of "Phoebodus" from Europe are reclassified to genus Keuperodus,[95] and if this specimen also can be attributed to Keuperodus, this would be the first record from North America.[96]
Reticulodus[97]R. synergus[97]The crown of its tooth bears a "reticulating ornamentation on [its] occlusal surface[.]"[97] Reticulodus remains are common throughout the Norian microvertebrate sites of the American southwest.[97]
Mooreodontus[98][99]M. moorei[98]Common in the lower Chinle Formation's microvertebrate localities.[98]A xenacanthiform shark.

Lobe-finned fish

Coelacanths

Actinistians (coelacanths) of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotesImages
Chinlea[100]C. sorenseni[101]
  • Ghost Ranch Quarry
  • Walt's Fish Quarry
  • Little Valley
  • Dolores River Canyon
AMNH 5657; AMNH 5652, 5656, 5660, 5704; AMNH 5653A freshwater actinisitan (coelacanth).
Indeterminate[103]MNA V346, scale; MNA V7045-7048, isolated quadrates

Lungfish

Dipnoans (lungfish) of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotes
Arganodus[104]A. dorotheae[104]
Indeterminate[104]Arganodus toothplates are the most common fossil in the formation from a non-tetrapod.[104] They are evenly distributed across strata, although some individual localities have very high concentrations.[104]Most Chinlean Arganodus fossils are isolated tooth plates.[104]
Ceratodus[104]C. dorotheae[104]Named by Case in 1921, in the 1980s it was referred to Arganodus.[104]

Ray-finned fish

Actinopterygians (ray-finned fish) of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotesImages
Australosomus[105]Indeterminate[106]Known only from two vertebrae.[106]
Cionichthys[101]C. dunklei
  • Colorado
  • Utah
A member of Redfieldiiformes.
HemicalypterusH. weiri
  • Utah
  • Church Rock Member
A member of Dapediiformes.[107]
Lasalichthys[101][108]L. hillsi[101]A member of Redfieldiiformes.
Indeterminate[109]Represented by isolated scales.[109]
Lophionotus[110]L. sanjuanensis[110]
  • Utah
A member of Semionotiformes.
L. chinleana[111]
  • Utah
  • Church Rock Member
A member of Semionotiformes.
Saurichthys[112]Indeterminate
  • Arizona
  • Upper Blue Mesa Member
A member of Saurichthyiformes.
Synorichthys[101]S. stewarti
  • Colorado
  • Utah
A member of Redfieldiiformes.
Tanaocrossus[101]T. kalliokoskii
  • Colorado
An enigmatic actinopterygian.[107]
Turseodus[101][113]T. dolorensis[101]A member of Palaeonisciformes.[101]
Indeterminate[114]Common.[114]Isolated scales from Chinle microvertebrate sites commonly have Turseodus-like ridges, however that feature is not unique to Turseodus and in 2005 Irmis advised researchers to regard them as indeterminate palaeoniscid remains.[114]

Plants

The Chinle Formation has a diverse flora of plant megafossils, though they are concentrated in only a few sites with suitable conditions. One of the most diverse floral communities is found near Fort Wingate, New Mexico. Paleobotanists have traditionally placed the Fort Wingate plant beds into the Monitor Butte Member, though more recently they are placed within the Bluewater Creek Formation, a subunit of the Chinle Formation first defined in 1989.[115] Some Fort Wingate plant fossils belong to the "Lake Ciniza beds", a localized patch of grey mudstone corresponding to an ancient lake.[116]

Another productive areas for plant fossils is Petrified Forest National Park in Arizona. Though petrified wood could be found through the entire stratigraphy of the park, most other plant fossils are exclusive to greenish mudstone layers adjacent to the Newspaper Rock sandstone bed in the Blue Mesa Member (formerly known as the "Lower Petrified Forest").

Conifers are the most common and diverse plants, including petrified wood and leafy branches from massive trees (Araucarioxylon, Pagiophyllum) as well as smaller shrubby forms (Pelourdea). Cycad and bennettitalean leaves and other remains make up a significant portion of the flora (Zamites, Nilssoniopteris, Williamsonia, etc.). Ferns (Cladophlebis, Phlebopteris, Clathropteris, Cynepteris, etc.) are abundant, with a range of growth habits including low shrubs, tree ferns, and palm-like fronds comparable to their modern relatives. Sphenophytes (horsetails: Neocalamites, Equistetites, Schizoneura, etc.) have low diversity but high abundance, and the largest Neocalamites fossils in the Chinle Formation could reach up to 6 meters (20 feet) in height. "Seed ferns" (Chilbinia, Marcouia?) ginkgophytes (Baiera), and small lycopods (Chinlea, Selaginella) were present but uncommon. The flora is rounded out by unusual low-growing gymnosperms such as Sanmiguelia (an angiosperm-like shrub), Dechellyia, and Dinophyton (possible relatives of Gnetales).[117][118]

The floral composition of the Chinle Formation (and other parts of Late Triassic North America) seem to shift with changes in climate over time. The lowest parts of the Chinle, such as the Shinarump Conglomerate, are dominated by the bennettitalean Eoginkgoites alongside the first occurrence of other persistent plants such as Phlebopteris, Equisetites, and most common conifer species. Subsequent subunits (such as the Blue Mesa Member, Monitor Butte Member, and Bluewater Creek Formation) are much more diverse, with a wide array of humidity-adapted plants making up the typical Chinle flora. This second floral zone is characterized by Dinophyton, a common but enigmatic shrubby gymnosperm. Plant fossils are rare in the upper part of the Chinle Formation, which was presumably much drier than the lower part. In these later layers, by far the most common plant fossils belong to Sanmiguelia (an endemic of southwestern North America) alongside conifers and horsetails.[119][120]

Gymnosperms

Gymnosperms of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotesImages
Araucariorhiza[121]A. joaeUncommonRoots of conifers similar to modern Araucariaceae. Possibly from the same plant as Araucarioxylon arizonicum.
Araucarioxylon[122]

A. arizonicum,

A. sp.[123]

AbundantPetrified trunks of large conifers possibly related to modern Araucariaceae.[126] State fossil of Arizona.
AraucaritesA. rudicula[127]
  • Arizona
  • New Mexico
  • Blue Mesa
  • Monitor Butte
Very rareLarge female conifer cones similar to those of araucariacean conifers.
Aricycas[128]A. paulae
  • Arizona
  • Blue Mesa ( = "Lower Petrified Forest")
Moderately commonPinnate cycad leaves
BaieraB. arizonica
  • Blue Mesa (= "Lower Petrified Forest")[117][119]
  • Bluewater Creek ( = "lower red member", formerly Monitor Butte)[129][125]
UncommonGinkgophyte leaves
BrachyphyllumB. sp, B. hegewaldia[130]UncommonConifer leaves and shoots
CarpolithusC. chinleanaRareSeeds of uncertain affinities
CephalotaxopsisC. sp.Conifer foliage
CharmorgiaC. dijolli
  • "Petrified Forest" sensu lato[117]
RareShort cycad stems
Chilbinia[131]C. lichii
  • Arizona
  • Shinarump
RareAn archaic seed fern with seeds and leaves more similar to Carboniferous-Permian seed ferns than to Triassic forms.
CreberanthusC. bealeii[127]
  • Arizona
Very rarePollen-bearing cones similar to those of some extinct "pteridosperms" (seed ferns). Associated with Alisporites opii, a common palynomorph.
DadoxylonD. chaneyi
  • "Petrified Forest" sensu lato[117]
Very rarePossible cordaitalean conifer wood.
Dechellyia[132]D. gormaniiUncommonAn enigmatic gymnosperm with narrow pinnate leaves, "clasping" leaf-like sporophylls, and winged seeds. Some leaves are affected by galls, similar to those formed by eriophyid mites in modern plants.[133][134]
DinophytonD. spinosus[135]CommonAn unusual gymnosperm combining needle-covered shoots with seed-bearing structures having the form of "pinwheel"-like clusters of tubular needles. Possibly related to Gnetales.
ElatocladusE. puercoensis[134]
  • Arizona
  • Blue Mesa
UncommonLeaf-bearing conifer shoots
EoginkgoitesE. sp., E. davidsonii[136]Common within its small stratigraphic rangeA bennettitalean with palm-shaped fronds similar to some ginkgo species.
GinkgoitesG. sp.RareA ginkgophyte
LindleycladusL. arizonicus[134]
  • Arizona
  • Blue Mesa
UncommonConifer shoots bearing Podozamites leaves. Formerly known as Podozamites arizonicus.
LyssoxylonL. grigsbyi
  • "Petrified Forest" sensu lato[117]
  • Bluewater Creek (formerly Monitor Butte)[125]
RareCycad trunks
MarcouiaM. neuropteroides
  • Blue Mesa (= "Lower Petrified Forest")[117][119]
  • Bluewater Creek (formerly Monitor Butte)[125]
  • Monitor Butte[133]
UncommonFern-like gymnosperm leaves of uncertain affinities. Some leaves are affected by feeding traces including crescent-shaped marginal incisions and oval-shaped holes. These were probably produced by beetles or orthopterans (grasshoppers and kin).[133]
MasculostrobusM. clathratus[132]
  • Arizona
  • Monitor Butte
Locally commonA pollen-bearing cone associated with lattice-shaped Equisetosporites chinleana pollen.
NilssoniopterisN. ciniza[116][125]UncommonLarge smooth-edged bennettitalean leaves, some of which were originally identified as Macrotaeniopteris magnifola.
OtozamitesO. macombii
  • Agua Zarca Sandstone[124]
UncommonBennettitalean leaves
Pagiophyllum

P. sp., P. duttonia,[116]

P. navajoensis,[116]

P. readiana,[116]

P. zuniana,[116]

P. simpsonii[137]

Locally very commonConifer leaves
Palissya

P. sp., P. diffusa,

P. sphenolepis

UncommonConifer leaves and shoots
PelourdeaP. poleoensisCommonA shrubby conifer with strap-like leaves arranged around a single narrow stem.
Podozamites

P. sp., P. emmonsi,

P. lanceolatus

UncommonConifer leafs and shoots
PramelreuthiaP. dubielli,[138] P. yazzi[138]
  • Arizona
  • New Mexico
  • Utah
  • Blue Mesa[119]
  • Monitor Butte
RareGymnosperm microsporophylls (pollen-bearing organs)
PterophyllumP. sp., P. braunianumUncommonBennettitalean leaves
SamaropsisS. sp., S. puercaUncommonSeeds of uncertain affinities
SanmigueliaS. lewisiiCommonAn unusual palm-like shrub, controversially suggested to be a relative or predecessor of angiosperms (flowering plants).
SchilderiaS. adamanicaRarePetrified stems of a conifer or gnetalean[126]
WilliamsoniaW. nizhonii[141]
  • Bluewater Creek ( = "lower red member", formerly Monitor Butte)[129][141][125]
RareA bennettitalean "flower" (female cone)
WoodworthiaW. arizonicaUncommonStems and petrified wood of a conifer related to A. arizonicum.[126][142]
Zamites

Z. sp., Z. occidentalis,

Z. powellii

Very commonBennettitalean leaves. Some leaves exhibit feeding traces, including sharp diagonal marginal traces and slot-like non-marginal traces. These traces were probably left by beetles.[133] Zamites powellii was formerly known as Otozamites powellii.

Ferns

Ferns of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotesImages
ApacheaA. arizonicaRareDipteridacean fern leaves, possibly damaged specimens of Clathropteris walkeri.[145]
Cladophlebis

C. daughertyi,[145] C. subfalcata,

C. yazzia,[130]

C. sp.

Very commonLarge sterile fern leaves of uncertain affinities
ClathropterisC. walkeriCommonDipteridacean fern leaves
Cynepteris[145]C. sp., C. lasiophora[145]CommonBipinnate fern leaves previously identified as Lonchopteris. Some leaves are affected by crescent-shaped marginal feeding traces, probably from beetles or orthopterans (grasshoppers and kin).[133]
Itopsidema[146]I. vancleavi
  • Arizona
  • Sonsela
UncommonStems of large osmundacean tree ferns. Some stems show evidence of being bored by oribatid mites.[147]
PhlebopterisP. smithii, P. utensisCommonMatoniacean fern leaves with a palmate structure
SphenopterisS. arizonicaUncommonSterile fern leaves of uncertain affinities. Some show evidence for marginal damage by insect feeding traces.[149]
ToditesT. fragilis
  • Blue Mesa (= "Lower Petrified Forest")[145]
  • Bluewater Creek (="lower red member", formerly Monitor Butte)[129][145][125]
UncommonOsmundacean fern leaves
Wingatea[145]W. plumosa
  • Blue Mesa (= "Lower Petrified Forest")[145][119]
  • Bluewater Creek (="lower red member", formerly Monitor Butte)[145][125]
RareGleicheniacean fern leaves previously named as a species of Coniopteris.

Other plants

Other plants of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotesImages
ChinleaC. sp., C. campii
  • "Petrified Forest" sensu lato[117]
UncommonSmall lycopod stems similar to shrubby forms such as Pleuromeia.[150]
EquisetitesE. sp., E. bradyi
  • Blue Mesa (= "Lower Petrified Forest")[117][119]
  • Bluewater Creek ("Ciniza Lake beds", formerly Monitor Butte)[116][125]
  • Shinarump[117]
CommonA horsetail indistinguishable from modern Equisetum.
Equisetocalis[151]E. muirii
  • Arizona
  • Blue Mesa
Concentrated in a narrow stratigraphic range (the Newspaper Rock sandstone bed)Small three-dimensional horsetail stems preserved in pyrite nodules.
IsoetitesI. circularis
  • "Petrified Forest" sensu lato[117]
RareQuillwort shoots
LycostrobusL. chinleanaRareHorsetail cones sometimes placed in the genus Equicalastrobus
NeocalamitesN. sp., N. virginiensis
  • "Siltstone"[123]
  • Church Rock?[144]
  • Owl Rock?[144]
  • "Petrified Forest" sensu lato[117]
  • Bluewater Creek ( = "lower red member" / "Ciniza Lake beds", formerly Monitor Butte)[129][116]
CommonStems and leaves of a giant sphenophyte (horsetail)
SchizoneuraS. harrisii
  • Bluewater Creek (formerly Monitor Butte)[125]
UncommonStems and leaves of a large sphenophyte (horsetail) more typical of Southern Hemisphere plant assemblages.
SelaginellaS. anasazia[132]
  • Arizona
  • Monitor Butte
UncommonA low-growing lycopsid similar to modern broad-leaved species of Selaginella, such as S. kraussiana

Arthropods

Arthropods of the Chinle Formation
GenusSpeciesStateStratigraphic positionAbundanceNotesImages
EnoplocytiaE. porteri[153]
  • Arizona
  • Sonsela?
Single well-preserved fossilAn erymid crayfish
Paleoscolytus[154]P. divergus
  • Arizona
  • Sonsela
A species of bark beetle, evidenced by trace fossils of tracks made on A. arizonicum specimens.

References

  1. ^ "Vertebrate Fauna; Parasuchia; Leptosuchus adamanensis, L. crosbiensis, and L. gregorii," Irmis (2005) p. 72, 74
  2. ^ "Vertebrate Fauna; Parasuchia; Pseudopalatus pristinus, P. buceros, and P. mccauleyi," Irmis (2005) p. 74-75
  3. ^ Parker, W. G. & Irmis, R. B. (2006). "A new species of the Late Triassic phytosaur Pseudopalatus (Archosauria: Pseudosuchia) from Petrified Forest National Park, Arizona". Museum of Northern Arizona Bulletin. 62: 126–143.
  4. ^ "Vertebrate Fauna; Parasuchia; 'Paleorhinus sp.'" Irmis (2005) p. 72
  5. ^ Stocker, Michelle R. (2010-09-01). "A new taxon of phytosaur (Archosauria: Pseudosuchia) from the Late Triassic (Norian) Sonsela Member (Chinle Formation) in Arizona, and a critical reevaluation of Leptosuchus Case, 1922". Palaeontology. 53 (5): 997–1022. Bibcode:2010Palgy..53..997S. doi:10.1111/j.1475-4983.2010.00983.x. ISSN 1475-4983. S2CID 83536253
  6. ^ Christian F. Kammerer; Richard J. Butler; Saswati Bandyopadhyay; Michelle R. Stocker (2016). "Relationships of the Indian phytosaur Parasuchus hislopi Lydekker, 1885". Papers in Palaeontology. 2 (1): 1–23. Bibcode:2016PPal....2....1K. doi:10.1002/spp2.1022. S2CID 83780331
  7. ^ Jones, Andrew S. & Butler, Richard J. (2018-12-10). "A new phylogenetic analysis of Phytosauria (Archosauria: Pseudosuchia) with the application of continuous and geometric morphometric character coding". PeerJ. 6. doi:10.7717/peerj.5901. ISSN 2167-8359. PMC 6292387. PMID 30581656
  8. ^ Stocker, M. R. (2012). "A new phytosaur (Archosauriformes, Phytosauria) from the Lot's Wife beds (Sonsela Member) within the Chinle Formation (Upper Triassic) of Petrified Forest National Park, Arizona". Journal of Vertebrate Paleontology. 32 (3): 573–586. Bibcode:2012JVPal..32..573S. doi:10.1080/02724634.2012.649815. S2CID 129527672
  9. ^ Hunt, A.P. and Lucas, S.G. 1993. A new phytosaur (Reptilia: Archosauria) genus from the uppermost Triassic of the western United States and its biochronological significance. In; The Nonmarine Triassic, Lucas and Morales, eds., New Mexico Museum of Natural History and Science Bulletin 3.
  10. ^ Long, R.A. and Murray, P.A. 1995. Late Triassic (Carnian and Norian) Tetrapods from the Southwestern United States. New Mexico Museum of Natural History and Science Bulletin 4. pp. 254.
  11. ^ Hungerbühler A. 2002. The Late Triassic phytosaur Mystriosuchus westphali, with a revision of the genus. Palaeontology 45 (2): 377-418
  12. ^ "Vertebrate Fauna; Stagonolepididae; Acaenasuchus geoffreyi," Irmis (2005) pp. 75-77
  13. ^ Marsh, Adam D.; Smith, Matthew E.; Parker, William G.; Irmis, Randall B.; Kligman, Ben T. (2020-10-12). "Skeletal Anatomy of Acaenasuchus Geoffreyi Long and Murry, 1995 (Archosauria: Pseudosuchia) and its Implications for the Origin of the Aetosaurian Carapace". Journal of Vertebrate Paleontology. 40 (4). Bibcode:2020JVPal..40E4885M. doi:10.1080/02724634.2020.1794885. hdl:10919/102375. ISSN 0272-4634
  14. ^ Parker, William G. (2016-01-21). "Revised phylogenetic analysis of the Aetosauria (Archosauria: Pseudosuchia); assessing the effects of incongruent morphological character sets". PeerJ. 4. doi:10.7717/peerj.1583. ISSN 2167-8359. PMC 4727975. PMID 26819845
  15. ^ "Vertebrate Fauna; Stagonolepididae," Irmis (2005) p. 77
  16. ^ "Vertebrate Fauna; Stagonolepididae; Stagonolepis wellesi," Irmis (2005) p. 77
  17. ^ "Vertebrate Fauna; Stagonolepididae," Irmis (2005) p. 75
  18. ^ "Vertebrate Fauna; Stagonolepididae; Desmatosuchus haplocerus," Irmis (2005) p. 75
  19. ^ "Vertebrate Fauna; Stagonolepididae; Desmatosuchus smalli," Irmis (2005) p. 75
  20. ^ Margulis-Ohnuma, M.; Ruebenstahl, A. A.; Meyer, D. L.; Bhullar, B.-A. S. (2026). "A short-snouted 'sphenosuchian' with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution". Proceedings of the Royal Society B: Biological Sciences. 293 (2069). doi:10.1098/rspb.2026.0130. PMID 41980740
  21. ^ "Vertebrate Fauna; Crocodylomorpha; Hesperosuchus agilis," Irmis (2005) pp. 79-80
  22. ^ Reyes, William A.; Parker, William G.; Heckert, Andrew B. (2023), "A new aetosaur (Archosauria: Pseudosuchia) from the upper Blue Mesa Member (Adamanian: Early–Mid Norian) of the Late Triassic Chinle Formation, northern Arizona, USA, and a review of the paratypothoracin Tecovasuchus across the southwestern USA", PaleoBios. 40 (9), doi:10.5070/P940961559. S2CID 259972056
  23. ^ Turner, Alan H.; Kernan, Ciara E.; Laing, Adam; Pritchard, Adam C.; Stocker, Michelle R.; Irmis, Randall B.; Smith, Nathan D.; Werning, Sarah; Nesbitt, Sterling J. (2026-05-26). "A new shuvosaurid (Archosauria, Poposauroidea) from the Late Triassic (Norian) Hayden Quarry of New Mexico, U.S.A.". Journal of Vertebrate Paleontology. doi:10.1080/02724634.2026.2618182. ISSN 0272-4634
  24. ^ "Vertebrate Fauna; Stagonolepididae; Paratypothorax sp.," Irmis (2005) p. 78
  25. ^ "Vertebrate Fauna; Stagonolepididae; 'Paratypothorax sp.' and 'Paratypothorax-Like Forms'," Irmis (2005) p. 78
  26. ^ Parker, William G. & Martz, Jeffrey W. (2010). "The Late Triassic (Norian) Adamanian–Revueltian tetrapod faunal transition in the Chinle Formation of Petrified Forest National Park, Arizona". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 101 (3–4): 231–260. Bibcode:2010EESTR.101..231P. doi:10.1017/S1755691011020020. ISSN 1755-6910. S2CID 140536630
  27. ^ "Vertebrate Fauna; Crocodylomorpha; 'Parrishia mccreai,'" Irmis (2005) pp. 80-81
  28. ^ "Vertebrate Fauna; Poposauridae; Poposaurus gracilis," Irmis (2005) p. 79
  29. ^ "Vertebrate Fauna; 'Rauisuchidae'; Postosuchus kirkpatricki," Irmis (2005) p. 78
  30. ^ "Vertebrate Fauna; Pseudosuchia; 'Revueltosaurus callenderi' and 'Revueltosaurus hunti,'" Irmis (2005) pp. 71-72
  31. ^ "Vertebrate Fauna; Pseudosuchia; Revueltosaurus callenderi," Irmis (2005) pp. 71-72
  32. ^ "Vertebrate Fauna; Pseudosuchia; Revueltosaurus hunti," Irmis (2005) p. 72
  33. ^ "Vertebrate Fauna; Stagonolepididae; "Desmatosuchus" chamaensis," Irmis (2005) p. 75
  34. ^ "Vertebrate Fauna; 'Rauisuchidae'; 'Saurosuchus sp.,'" Irmis (2005) p. 78
  35. ^ "Vertebrate Fauna; Poposauridae; 'Chatterjeea elegans,'" Irmis (2005) p. 79
  36. ^ Nesbitt, S. J. & Chatterjee, S. (2024). "The osteology of Shuvosaurus inexpectatus, a shuvosaurid pseudosuchian from the Upper Triassic Post Quarry, Dockum Group of Texas, USA". The Anatomical Record. 307 (4): 1175–1238. doi:10.1002/ar.25376. hdl:10919/117738. PMID 38258540
  37. ^ Smith, Elliott Armour & Sidor, Christian A. (2026-03-08). "Osteology and relationships of a new shuvosaurid (Pseudosuchia, Poposauroidea) from the Upper Triassic Chinle Formation of Petrified Forest National Park, Arizona, U.S.A.". Journal of Vertebrate Paleontology. doi:10.1080/02724634.2025.2604859. ISSN 0272-4634
  38. ^ "Vertebrate Fauna; Stagonolepididae; Typothorax coccinarum," Irmis (2005) pp. 77-78
  39. ^ Emily J. Lessner; Michelle R. Stocker; Nathan D. Smith; Alan H. Turner; Randall B. Irmis; Sterling J. Nesbitt (2016). "A new rauisuchid (Archosauria, Pseudosuchia) from the Upper Triassic (Norian) of New Mexico increases the diversity and temporal range of the clade". PeerJ. 4: e2336. doi:10.7717/peerj.2336.
  40. ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Triassic, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 518–521. ISBN 0-520-24209-2.
  41. ^ Zeigler, K. E.; Kelley, S.; Geissman, J. W. (2008). "Revisions to stratigraphic nomenclature of the Upper Triassic Chinle Group in New Mexico: New insights from geologic mapping, sedimentology, and magnetostratigraphic/paleomagnetic data". Rocky Mountain Geology. 43 (2): 121–141. Bibcode:2008RMGeo..43..121Z. doi:10.2113/gsrocky.43.2.121
  42. ^ "Vertebrate Fauna; Pseudosuchia; Revueltosaurus callenderi," Irmis (2005) p. 81
  43. ^ Kligman, Ben T.; Whatley, Robin L.; Ramezani, Jahandar; Marsh, Adam D.; Lyson, Tyler R.; Fitch, Adam J.; Parker, William G.; Behrensmeyer, Anna K. (2025-07-22). "Unusual bone bed reveals a vertebrate community with pterosaurs and turtles in equatorial Pangaea before the end-Triassic extinction". Proceedings of the National Academy of Sciences. 122 (29). Bibcode:2025PNAS..12205513K. doi:10.1073/pnas.2505513122. PMC 12304912. PMID 40623204
  44. ^ See Nesbitt et al. (2005) and Ezcurra (2006).
  45. ^ Jeffrey W. Martz & Bryan J. Small (2019). "Non-dinosaurian dinosauromorphs from the Chinle Formation (Upper Triassic) of the Eagle Basin, northern Colorado: Dromomeron romeri (Lagerpetidae) and a new taxon, Kwanasaurus williamparkeri (Silesauridae)". PeerJ. 7. doi:10.7717/peerj.7551. PMC 6730537. PMID 31534843
  46. ^ Srivastava, Simba & Nesbitt, Sterling J. (2026-04-14). "A new taxon of saurischian dinosaur from the Coelophysis Quarry of New Mexico, USA (Triassic: latest Norian or Rhaetian) highlights herrerasaurian diversity in the latest Triassic". Papers in Palaeontology. 12 (2). doi:10.1002/spp2.70069. ISSN 2056-2799
  47. ^ Schubul, Alaska N.; Marsh, Adam D.; Kligman, Ben T. (2025-08-01). "A diverse assemblage of tanystropheid archosauromorphs from the continental interior of Late Triassic Pangea includes a new taxon (Akidostropheus oligos gen. et sp. nov.)". Palaeodiversity. 18 (1). doi:10.18476/pale.v18.a5. ISSN 1867-6294
  48. ^ "Vertebrate Fauna; Archosauriformes; Crosbysaurus harrisae," Irmis (2005) p. 71
  49. ^ William G. Parker; Sterling J. Nesbitt; Adam D. Marsh; Ben T. Kligman; Kenneth Bader (2021). "First occurrence of Doswellia cf. D. kaltenbachi (Archosauriformes) from the Late Triassic (middle Norian) Chinle Formation of Arizona and its implications on proposed biostratigraphic correlations across North America during the Late Triassic". Journal of Vertebrate Paleontology. 41 (3). Bibcode:2021JVPal..41E6196P. doi:10.1080/02724634.2021.1976196. S2CID 243474578
  50. ^ Marsh, Adam D.; Parker, William G.; Nesbitt, Sterling J.; Kligman, Ben T.; Stocker, Michelle R. (2022). "Puercosuchus traverorum n. gen. n. sp.: a new malerisaurine azendohsaurid (Archosauromorpha: Allokotosauria) from two monodominant bonebeds in the Chinle Formation (Upper Triassic, Norian) of Arizona". Journal of Paleontology. 96 (S90): 1–39. Bibcode:2022JPal...96S...1M. doi:10.1017/jpa.2022.49. ISSN 0022-3360
  51. ^ Brenen M. Wynd; Sterling J. Nesbitt; Michelle R. Stocker; Andrew B. Heckert (2020). "A detailed description of Rugarhynchos sixmilensis, gen. et comb. nov. (Archosauriformes, Proterochampsia), and cranial convergence in snout elongation across stem and crown archosaurs". Journal of Vertebrate Paleontology. 39 (6). doi:10.1080/02724634.2019.1748042. S2CID 219917329
  52. ^ Lucas, Spencer & Heckert, Andrew (2012). "A new species of the enigmatic archosauromorph Doswellia from the Upper Triassic Bluewater Creek Formation, New Mexico, USA". Palaeontology. 55 (6): 1333–1348. Bibcode:2012Palgy..55.1333H. doi:10.1111/j.1475-4983.2012.01200.x. S2CID 15431716
  53. ^ Heckert, A. B.; Nesbitt, S. J.; Stocker, M. R.; Schneider, V. P.; Hoffman, D. K.; Zimmer, B. W. (2021). "A new short-faced archosauriform from the Upper Triassic Placerias/Downs' quarry complex, Arizona, USA, expands the morphological diversity of the Triassic archosauriform radiation". The Science of Nature. 108 (4). Bibcode:2021SciNa.108...32H. doi:10.1007/s00114-021-01733-1. PMC 8253714. PMID 34213630
  54. ^ Pritchard, Adam C.; Turner, Alan H.; Nesbitt, Sterling J.; Irmis, Randall B.; Smith, Nathan D. (2015-03-04). "Late Triassic tanystropheids (Reptilia, Archosauromorpha) from northern New Mexico (Petrified Forest Member, Chinle Formation) and the biogeography, functional morphology, and evolution of Tanystropheidae". Journal of Vertebrate Paleontology. 35 (2). Bibcode:2015JVPal..35E1186P. doi:10.1080/02724634.2014.911186. ISSN 0272-4634. S2CID 130089407
  55. ^ "Vertebrate Fauna; Archosauromorpha; Tanytrachelos sp.," Irmis (2005) p. 70
  56. ^ "Vertebrate Fauna; Archosauriformes; Tecovasaurus murryi," Irmis (2005) p. 71
  57. ^ "Vertebrate Fauna; Archosauromorpha; Trilophosaurus buettneri, Trilophosaurus jacobsi, Trilophosaurus sp." Irmis (2005) p. 70
  58. ^ "Vertebrate Fauna; Archosauromorpha; Trilophosaurus buettneri," Irmis (2005) p. 70
  59. ^ "Abstract," Mueller and Parker (2006) p. 119
  60. ^ "Vertebrate Fauna; Archosauromorpha; Trilophosaurus jacobsi," Irmis (2005) p. 70
  61. ^ Ben T. Kligman; Adam D. Marsh; Sterling J. Nesbitt; William G. Parker; Michelle R. Stocker (2020). "New trilophosaurid species demonstrates a decline in allokotosaur diversity across the Adamanian-Revueltian boundary in the Late Triassic of western North America". Palaeodiversity. 13 (1): 25–37. doi:10.18476/pale.v13.a3
  62. ^ "Vertebrate Fauna; Archosauriformes; Vancleavea campi," Irmis (2005) p. 71
  63. ^ Nesbitt, S.J.; Stocker, M.R.; Small, B.J.; Downs, A. (November 26, 2009). "The osteology and relationships of Vancleavea campi (Reptilia: Archosauriformes)". Zoological Journal of the Linnean Society. 157 (4): 814–864. doi:10.1111/j.1096-3642.2009.00530.x
  64. ^ "Vertebrate Fauna; Reptilia incertae sedis; Acallosuchus rectori," Irmis (2005) pp. 69-70
  65. ^ Gabriel S. Gonçalves & Christian A. Sidor (2019). "A new drepanosauromorph, Ancistronychus paradoxus n. gen. et sp., from the Chinle Formation of Petrified Forest National Park, Arizona, USA". PaleoBios. 36: ucmp_paleobios_46203.
  66. ^ Pritchard, Adam C. & Nesbitt, Sterling J. (2017-10-01). "A bird-like skull in a Triassic diapsid reptile increases heterogeneity of the morphological and phylogenetic radiation of Diapsida". Royal Society Open Science. 4 (10). Bibcode:2017RSOS....470499P. doi:10.1098/rsos.170499. ISSN 2054-5703. PMC 5666248. PMID 29134065
  67. ^ "Vertebrate Fauna; Parareptilia; Colognathus obscurus," Irmis (2005) p. 69
  68. ^ Pritchard, Adam C.; Turner, Alan H.; Irmis, Randall B.; Nesbitt, Sterling J.; Smith, Nathan D. (2016-10-24). "Extreme Modification of the Tetrapod Forelimb in a Triassic Diapsid Reptile". Current Biology. 26 (20): 2779–2786. Bibcode:2016CBio...26.2779P. doi:10.1016/j.cub.2016.07.084. ISSN 0960-9822. PMID 27693141
  69. ^ Sodano, M. P.; Kligman, B. T.; Marsh, A. D.; Pritchard, A. C.; Stocker, M. R.; Parker, W. G.; Gonçalves, G. S.; Nesbitt, S. J. (2025). "Gross anatomy and histological analysis of manual unguals of Drepanosauromorpha (Sauropsida: Diapsida) and description of a new taxon from the Sonsela Member of the Chinle Formation (Late Triassic) of the southwestern United States". The Anatomical Record. doi:10.1002/ar.70057. PMID 41126689
  70. ^ Burch, H. E.; Eddins, H.-M. S.; Stocker, M. R.; Kligman, B. T.; Marsh, A. D.; Parker, W. G.; Nesbitt, S. J. (2024). "A small venomous reptile from the Late Triassic (Norian) of the southwestern United States". PeerJ. 12: e18279. doi:10.7717/peerj.18279. PMC 11485104. PMID 39421413
  71. ^ Jenkins, Kelsey M.; Bell, Christopher J.; Hancox, P. John; Lewis, Patrick J. (2023-09-03). "A new species of Palacrodon and a unique form of tooth attachment in reptiles". Journal of Vertebrate Paleontology. 43 (5). Bibcode:2023JVPal..43E8658J. doi:10.1080/02724634.2024.2328658. ISSN 0272-4634
  72. ^ Jenkins, Kelsey M.; Meyer, Dalton L.; Lewis, Patrick J.; Choiniere, Jonah N.; Bhullar, Bhart-Anjan S. (2022). "Re-description of the early Triassic diapsid Palacrodon from the lower Fremouw formation of Antarctica". Journal of Anatomy. 241 (6): 1441–1458. doi:10.1111/joa.13770. PMC 9644968. PMID 36168715. S2CID 252565757
  73. ^ Jenkins, Xavier A.; Pritchard, Adam C.; Marsh, Adam D.; Kligman, Ben T.; Sidor, Christian A.; Reed, Kaye E. (2020). "Using manual ungual morphology to predict substrate use in the Drepanosauromorpha and the description of a new species". Journal of Vertebrate Paleontology. 40 (5). Bibcode:2020JVPal..40E0058J. doi:10.1080/02724634.2020.1810058
  74. ^ Listed as cf. Uatchitodon sp. in "Vertebrate Fauna; Reptilia incertae sedis; Cf. Uatchitodon sp," Irmis (2005) p. 69
  75. ^ Mitchell; Heckert, Andrew B.; Sues, Hans-Dieter (2010). "Grooves to tubes: evolution of the venom delivery system in a Late Triassic "reptile"". Naturwissenschaften. 97 (12): 1117–1121. Bibcode:2010NW.....97.1117M. doi:10.1007/s00114-010-0729-0. PMID 21060984. S2CID 10093308
  76. ^ "Vertebrate Fauna; Reptilia incertae sedis; Cf. Uatchitodon sp," Irmis (2005) p. 69
  77. ^ Heckert, Andrew B.; Lucas, Spencer G.; Rinehart, Larry F.; Hunt, Adrian P. (2008-07-01). "A New Genus and Species of Sphenodontian from the Ghost Ranch Coelophysis Quarry (upper Triassic: Apachean), Rock Point Formation, New Mexico, Usa". Palaeontology. 51 (4): 827–845. Bibcode:2008Palgy..51..827H. doi:10.1111/j.1475-4983.2008.00786.x. ISSN 1475-4983
  78. ^ Nicholas C. Fraser; Randall B. Irmis; David K. Elliott (2005). "A procolophonid (Parareptilia) from the Owl Rock Member, Chinle Formation of Utah, USA". Palaeontologia Electronica. 8 (1): Article Number 8.1.13.
  79. ^ Mueller, Bill D.; Small, Bryan J.; Jenkins, Xavier; Huttenlocker, Adam K.; Chatterjee, Sankar (2023). "Cranial anatomy of Libognathus sheddi Small, 1997 (Parareptilia, Procolophonidae) from the Upper Triassic Dockum Group of West Texas, USA". The Anatomical Record. 307 (4): 1421–1441. doi:10.1002/ar.25364. PMID 38071453
  80. ^ Ben T. Kligman; Adam D. Marsh; Hans-Dieter Sues; Christian A. Sidor (2020). "A new non-mammalian eucynodont from the Chinle Formation (Triassic: Norian), and implications for the early Mesozoic equatorial cynodont record". Biology Letters. 16 (11). doi:10.1098/rsbl.2020.0631. PMC 7728676. PMID 33142088
  81. ^ "Vertebrate Fauna; Amniota incertae sedis; Kraterokheirodon colberti," Irmis (2005) p. 69
  82. ^ "Vertebrate Fauna; Synapsida; Placerias hesternus," Irmis (2005) p. 82
  83. ^ "Vertebrate Fauna; Temnospondyli; Apachesaurus gregorii" Irmis (2005) pp. 67-68
  84. ^ Mueller (2007)
  85. ^ Gee, Bryan M.; Parker, William G.; Marsh, Adam D. (2020). "Redescription of Anaschisma (Temnospondyli: Metoposauridae) from the Late Triassic of Wyoming and the phylogeny of the Metoposauridae". Journal of Systematic Palaeontology. 18 (3): 233–258. Bibcode:2020JSPal..18..233G. doi:10.1080/14772019.2019.1602855. S2CID 190896742
  86. ^ "Vertebrate Fauna; Temnospondyli; Buettneria perfecta" Irmis (2005) p. 67. Note that Koskinonodon was listed under the preoccupied (see Mueller 2007) name Buettneria in the preceding reference.
  87. ^ Jason D. Pardo; Bryan J. Small; Adam K. Huttenlocker (2017). "Stem caecilian from the Triassic of Colorado sheds light on the origins of Lissamphibia". Proceedings of the National Academy of Sciences of the United States of America. 114 (27): E5389–E5395. Bibcode:2017PNAS..114E5389P. doi:10.1073/pnas.1706752114. PMC 5502650. PMID 28630337
  88. ^ Kligman, Ben T.; Gee, Bryan M.; Marsh, Adam D.; Nesbitt, Sterling J.; Smith, Matthew E.; Parker, William G.; Stocker, Michelle R. (2023-01-25). "Triassic stem caecilian supports dissorophoid origin of living amphibians". Nature. 614 (7946): 102–107. Bibcode:2023Natur.614..102K. doi:10.1038/s41586-022-05646-5. hdl:10919/113568. ISSN 1476-4687. PMC 9892002. PMID 36697827. S2CID 256272986
  89. ^ Michelle R. Stocker; Sterling J. Nesbitt; Ben T. Kligman; Daniel J. Paluh; Adam D. Marsh; David C. Blackburn; William G. Parker (2019). "The earliest equatorial record of frogs from the Late Triassic of Arizona". Biology Letters. 15 (2). doi:10.1098/rsbl.2018.0922. hdl:10919/87931. PMC 6405462. PMID 30958136
  90. ^ "Vertebrate Fauna; Chondrichthyes; Acrodus sp." Irmis (2005) p. 65
  91. ^ The Petrified Forest and Sonsela Acrodus specimens are actually Reticulodus. See "Vertebrate Fauna; Chondrichthyes; Acrodus sp." Irmis (2005) p. 65 for details.
  92. ^ "Vertebrate Fauna; Chondrichthyes; Lonchidion humblei," Irmis (2005) p. 65
  93. ^ Fischer, Jan; Axsmith, Brian J.; Ash, Sidney R. (2010-03-01). "First unequivocal record of the hybodont shark egg capsule Palaeoxyris in the Mesozoic of North America". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 255 (3): 327–344. Bibcode:2010NJGPA.255..327F. doi:10.1127/0077-7749/2009/0028. ISSN 0077-7749
  94. ^ "Vertebrate Fauna; Chondrichthyes; Phoebodus sp." Irmis (2005) p. 65
  95. ^ Ivanov, Alexander O.; Duffin, Christopher J.; Richter, Martha (2021-03-04). "Youngest jalodontid shark from the Triassic of Europe and a revision of the Jalodontidae". Journal of Vertebrate Paleontology. 41 (2). Bibcode:2021JVPal..41E1259I. doi:10.1080/02724634.2021.1931259. ISSN 0272-4634. S2CID 237518008
  96. ^ Hodnett, John-Paul; Tweet, Justin; Santucci, Vincent (2022). "THE OCCURRENCE OF FOSSIL CARTILAGINOUS FISHES (CHONDRICHTHYES) WITHIN THE PARKS AND MONUMENTS OF THE NATIONAL PARK SERVICE". Fossil Record 8. New Mexico Museum of Natural History and Science Bulletin 90
  97. ^ "Vertebrate Fauna; Chondrichthyes; Reticulodus synergus," Irmis (2005) p. 65
  98. ^ "Vertebrate Fauna; Chondrichthyes; 'Xenacanthus' moorei," Irmis (2005) p. 64
  99. ^ Bhat, Mohd Shafi; Ray, Sanghamitra; Datta, P. M. (2018-09-01). "A new assemblage of freshwater sharks (Chondrichthyes: Elasmobranchii) from the Upper Triassic of India". Geobios. 51 (4): 269–283. Bibcode:2018Geobi..51..269B. doi:10.1016/j.geobios.2018.06.004. ISSN 0016-6995
  100. ^ Listed as cf. Chinlea sp. in "Vertebrate Fauna; Temnospondyli; Cf. Chinlea sp." Irmis (2005) p. 67
  101. ^ Bobb Schaeffer (1967). "Late Triassic fishes from the western United States". Bulletin of the American Museum of Natural History. 135: 285–342. hdl:2246/1125
  102. ^ Milner, A.; Mickelson, Debra L.; Kirkland, J.; Harris, Jerald D. (2006). "Reinvestigation of Late Triassic fish sites in the Chinle Group, San Juan County, Utah: new discoveries". Museum of Northern Arizona Bulletin. 62: 163–165. S2CID 131108700
  103. ^ "Vertebrate Fauna; Temnospondyli; Cf. Chinlea sp." Irmis (2005) p. 67
  104. ^ "Vertebrate Fauna; Temnospondyli; Arganodus sp." Irmis (2005) p. 67
  105. ^ Listed as "cf. Australosomus" in "Vertebrate Fauna; Osteichthyes; Cf. Australosomus sp." Irmis (2005) p. 66-67
  106. ^ "Vertebrate Fauna; Osteichthyes; Cf. Australosomus sp." Irmis (2005) p. 66-67
  107. ^ Sarah Z. Gibson (2016). "Redescription and Phylogenetic Placement of †Hemicalypterus weiri Schaeffer, 1967 (Actinopterygii, Neopterygii) from the Triassic Chinle Formation, Southwestern United States: New Insights into Morphology, Ecological Niche, and Phylogeny". PLOS ONE. 11 (9). Bibcode:2016PLoSO..1163657G. doi:10.1371/journal.pone.0163657. PMC 5033578. PMID 27657923
  108. ^ Listed as "cf. Lasalichthyes" in "Vertebrate Fauna; Osteichthyes; Cf. Lasalichthyes sp." Irmis (2005) p. 66
  109. ^ "Vertebrate Fauna; Osteichthyes; Cf. Lasalichthyes sp." Irmis (2005) p. 66
  110. ^ Sarah Z. Gibson (2013). "A new hump-backed ginglymodian fish (Neopterygii, Semionotiformes) from the Upper Triassic Chinle Formation of southeastern Utah". Journal of Vertebrate Paleontology. 33 (5): 1037–1050. Bibcode:2013JVPal..33.1037G. doi:10.1080/02724634.2013.758125. S2CID 129797885
  111. ^ Sarah Z. Gibson (2013). "Biodiversity and Evolutionary History of †Lophionotus (Neopterygii: †Semionotiformes) from the Western United States". Copeia. 2013 (4): 582–603. doi:10.1643/CI-12-028. S2CID 85755730
  112. ^ Ben T. Kligman; William G. Parker; Adam D. Marsh (2017). "First record of Saurichthys (Actinopterygii) from the Upper Triassic (Chinle Formation, Norian) of western North America". Journal of Vertebrate Paleontology. 37 (5). Bibcode:2017JVPal..37E7304K. doi:10.1080/02724634.2017.1367304. S2CID 134301176
  113. ^ Listed as "cf. Turseodus" in "Vertebrate Fauna; Osteichthyes; Cf. Turseodus sp." Irmis (2005) p. 66
  114. ^ "Vertebrate Fauna; Osteichthyes; Cf. Turseodus sp." Irmis (2005) p. 66
  115. ^ Lucas, S.G. & Hayden, S.N. (1989). "Triassic stratigraphy of west-central New Mexico". New Mexico Geological Society Field Conference Guidebook. 40: 191–211.
  116. ^ Ash, Sidney R. (1978). "4: Plant Megafossils". Geology, paleontology, and paleoecology of a Late Triassic lake, western New Mexico. Vol. 25. Brigham Young University Geology Studies.
  117. ^ Ash, Sidney R. (1989). "A catalog of Upper Triassic plant megafossils of the western United States through 1988". Dawn of the age of dinosaurs in the American Southwest. Lucas, S.G. & Hunt, A.P. (eds.). Albuquerque: New Mexico Museum of Natural History. pp. 189–222.
  118. ^ Kustatscher, Evelyn; Ash, Sidney R.; Karasev, Eugeny; Pott, Christian; Vajda, Vivi; Yu, Jianxin; McLoughlin, Stephen (2018), "Flora of the Late Triassic", The Late Triassic World. Vol. 46, Topics in Geobiology, Tanner, Lawrence H. (ed.), Cham: Springer International Publishing, pp. 545–622, doi:10.1007/978-3-319-68009-5_13. ISBN 978-3-319-68008-8, retrieved 2022-11-21
  119. ^ Parker, William G. (2006). "The stratigraphic distribution of major fossil localities in Petrified Forest National Park, Arizona". A century of research at Petrified Forest National Park: geology and paleontology. Vol. 62. Parker, William G.; Ash, Sidney R.; Irmis, Randall B. (eds.). Museum of Northern Arizona. pp. 46–64. ISBN 0-89734-120-1. OCLC 71015548
  120. ^ Lucas, Spencer G. (2013). "Plant megafossil biostratigraphy and biochronology, Upper Triassic Chinle Group, Western USA". New Mexico Museum of Natural History and Science Bulletin. 61: 354–365.
  121. ^ Daugherty, Lyman H. (1963). "Triassic Roots from the Petrified Forest National Park". American Journal of Botany. 50 (8): 802–805. Bibcode:1963AmJB...50..802D. doi:10.1002/j.1537-2197.1963.tb10649.x. hdl:2027.42/141301. ISSN 0002-9122
  122. ^ Frank H. Knowlton (1889). "New species of fossil wood (Araucarioxylon arizonicum) from Arizona and New Mexico". Proceedings of the United States National Museum. 11 (676): 1–5. doi:10.5479/si.00963801.11-676.1
  123. ^ Ash, Sidney R. (1987). "The Upper Triassic Red Bed Flora of the Colorado Plateau, Western United States". Journal of the Arizona-Nevada Academy of Science. 22 (1): 95–105. JSTOR 40024387
  124. ^ Ash, Sidney R. (1974). "Upper Triassic plants of Canon del Cobre, New Mexico". New Mexico Geological Society Guidebook. 25: 179–184.
  125. ^ Ash, Sidney R. (1989). "The upper Triassic Chinle flora of the Zuni Mountains, New Mexico". Southeastern Colorado Plateau. Vol. 40. New Mexico Geological Society Guidebook. pp. 225–230. doi:10.56577/ffc-40.225. S2CID 251985942
  126. ^ "Trees to Stone". National Park Service. 2006. Archived September 7, 2015 at the Wayback Machine. Retrieved October 3, 2010.
  127. ^ Axsmith, Brian J. & Ash, Sidney R. (2006). "Two rare fossil cones from the Upper Triassic Chinle Formation in Petrified Forest National Park, Arizona, and New Mexico". Museum of Northern Arizona Bulletin. 62: 82–94.
  128. ^ Ash, Sidney R. (1991). "A New Pinnate Cycad Leaf from the Upper Triassic Chinle Formation of Arizona". Botanical Gazette. 152 (1): 123–131. doi:10.1086/337871. ISSN 0006-8071. S2CID 83627771
  129. ^ Ash, Sidney R. (1967). "The Chinle (Upper Triassic) megaflora of the Zuni Mountains, New Mexico". Defiance-Zuni-Mt. Taylor region, Arizona and New Mexico. Vol. 18. New Mexico Geological Society Guidebook. pp. 125–131. doi:10.56577/ffc-18.125. S2CID 11630110
  130. ^ Ash, Sidney R. (1973). "Two New Late Triassic Plants from the Petrified Forest of Arizona". Journal of Paleontology. 47 (1): 46–53. JSTOR 1302865
  131. ^ Ash, Sidney R. (2006). "Chilbinia Gen. Nov., an Archaic Seed Fern in the Late Triassic Chinle Formation of Arizona, USA". Palaeontology. 49 (2): 237–245. Bibcode:2006Palgy..49..237A. doi:10.1111/j.1475-4983.2006.00542.x. ISSN 0031-0239. S2CID 129438630
  132. ^ Ash, Sidney R. (1972). "Late Triassic plants from the Chinle Formation in north-eastern Arizona". Palaeontology. 15 (4): 598–618.
  133. ^ Ash, Sidney (1996). "Evidence of arthropod-plant interactions in the Upper Triassic of the southwestern United States". Lethaia. 29 (3): 237–248. Bibcode:1996Letha..29..237A. doi:10.1111/j.1502-3931.1996.tb01657.x. ISSN 0024-1164
  134. ^ Ash, Sidney R. (2014-06-01). "Contributions to the Upper Triassic Chinle flora in the American southwest". Palaeobiodiversity and Palaeoenvironments. 94 (2): 279–294. Bibcode:2014PdPe...94..279A. doi:10.1007/s12549-014-0150-3. ISSN 1867-1608. S2CID 129297877
  135. ^ Ash, Sidney R. (1970). "Dinophyton, a problematical new plant genus from the Upper Triassic of the south-western United States". Palaeontology. 13 (4): 646–663.
  136. ^ Ash, Sidney R. (1977). "An unusual bennettitalean leaf from the Upper Triassic of the south-western United States". Palaeontology. 20 (3): 641–659.
  137. ^ Ash, Sidney R. (1970). "Pagiophyllum simpsonii, a New Conifer from the Chinle Formation (Upper Triassic) of Arizona". Journal of Paleontology. 44 (5): 945–952. JSTOR 1302730
  138. ^ Ash, Sidney & Litwin, Ronald J. (1996). "Two new species of the pinnate microsporophyll Pramelreuthia from the upper Triassic of the southwestern United States". American Journal of Botany. 83 (8): 1091–1099. Bibcode:1996AmJB...83.1091A. doi:10.1002/j.1537-2197.1996.tb12807.x
  139. ^ Ash, Sidney R. & Hasiotis, Stephen T. (2013-04-01). "New occurrences of the controversial Late Triassic plant fossil Sanmiguelia Brown and associated ichnofossils in the Chinle Formation of Arizona and Utah, USA". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 268 (1): 65–82. Bibcode:2013NJGPA.268...65A. doi:10.1127/0077-7749/2013/0316. ISSN 0077-7749
  140. ^ Ash, Sidney R. (1982). "Occurrence of the Controversial Plant Fossil Sanmiguelia cf. S. lewisi Brown in the Upper Triassic of Utah". Journal of Paleontology. 56 (3): 751–754. JSTOR 1304404
  141. ^ Ash, Sidney R. (1968). "A new species of Williamsonia from the Upper Triassic Chinle Formation of New Mexico". Journal of the Linnean Society of London, Botany. 61 (384): 113–120. doi:10.1111/j.1095-8339.1968.tb00108.x
  142. ^ "Fossil Trees or Petrified Wood". University of Arizona. 2012. Retrieved October 14, 2021.
  143. ^ Herrick, Alisa S.; Fastovsky, David E.; Hoke, Gregory D. (1999). "OCCURRENCES OF ZAMITES POWELLII IN OLDEST NORIAN STRATA IN PETRIFIED FOREST NATIONAL PARK, ARIZONA". National Park Service Paleontological Research. 4: 91–95.
  144. ^ Milner, Andrew C. (2006). "Plant fossils from the Owl Rock or Church Rock members, Chinle Formation, San Juan County, Utah". New Mexico Museum of Natural History & Science Bulletin. 37: 410–413.
  145. ^ Ash, S.R. (1969). "Ferns from the Chinle Formation (Upper Triassic) in the Fort Wingate area, New Mexico". United States Geological Survey, Professional Paper. 613-D: 1–40. Professional Paper. Bibcode:1969usgs.rept....2A. doi:10.3133/pp613d. ISSN 2330-7102
  146. ^ Daugherty, Lyman H. (1960). "Itopsidema, A New Genus of the Osmundaceae from the Triassic of Arizona". American Journal of Botany. 47 (9): 771–777. Bibcode:1960AmJB...47..771D. doi:10.1002/j.1537-2197.1960.tb07164.x
  147. ^ Ash, Sidney (2000). "Evidence of oribatid mite herbivory in the stem of a Late Triassic tree fern from Arizona". Journal of Paleontology. 74 (6): 1065–1071. doi:10.1666/0022-3360(2000)074<1065:EOOMHI>2.0.CO;2. ISSN 0022-3360. S2CID 86324641
  148. ^ Ash, Sidney; Litwin, Ronald J.; Traverse, Alfred (1982). "The Upper Triassic fern Phlebopteris smithii (Daugherty) Arnold and its spores". Palynology. 6 (1): 203–219. Bibcode:1982Paly....6..203A. doi:10.1080/01916122.1982.9989242. ISSN 0191-6122
  149. ^ Ash, Sidney (1999). "An Upper Triassic Sphenopteris Showing Evidence of Insect Predation from Petrified Forest National Park, Arizona". International Journal of Plant Sciences. 160 (1): 208–215. Bibcode:1999IJPlS.160..208A. doi:10.1086/314115. ISSN 1058-5893. S2CID 85020560
  150. ^ Miller, Charles N. (1968). "The Lepidophytic Affinities of the Genus Chinlea and Osmundites Walkeri". American Journal of Botany. 55 (1): 109–115. Bibcode:1968AmJB...55..109M. doi:10.1002/j.1537-2197.1968.tb06950.x
  151. ^ Rothwell, Gar W. & R. Ash, Sidney (2015). "Internal anatomy of the Late Triassic Equisetocaulis gen. nov., and the evolution of modern horsetails". The Journal of the Torrey Botanical Society. 142 (1): 27–37. doi:10.3159/TORREY-D-14-00042.1. ISSN 1095-5674. S2CID 86841184
  152. ^ Holt, Edward L. (1947). "Upright Trunks of Neocalamites from the Upper Triassic of Western Colorado". The Journal of Geology. 55 (6): 511–513. Bibcode:1947JG.....55..511H. doi:10.1086/625462. ISSN 0022-1376. S2CID 129374986
  153. ^ Miller, Gary L. & Ash, Sidney R. (1988). "The oldest freshwater decapod crustacean, from the Triassic of Arizona". Palaeontology. 31 (2): 273–279.
  154. ^ Sidney R. Ash & Geoffrey T. Creber (2000). "The Late Araucarioxylon arizonicum Trees of the Petrified Forest National Park, Arizona, USA". Palaeontology. 43: 22–23. doi:10.1111/1475-4983.00116. S2CID 128691956

Bibliography

  • Irmis, R. B. 2005. The vertebrate fauna of the Upper Triassic Chinle Formation in northern Arizona. p. 63-88. in S.J. Nesbitt, W.G. Parker, and R.B. Irmis (eds.) 2005. Guidebook to the Triassic formations of the Colorado Plateau in northern Arizona: Geology, Paleontology, and History. Mesa Southwest Museum Bulletin 9.
  • Mueller, B. D. and Parker, W. G. 2006. A new species of Trilophosaurus (Diapsida: Archosauromorpha) from the Sonsela Member (Chinle Formation) of Petrified Forest National Park, Arizona. In W. G. Parker, S. R. Ash & R. B. Irmis (eds.), A Century of Research at Petrified Forest National Park, 1906-2006: Geology and Paleontology. Museum of Northern Arizona Bulletin 62:119-125
  • Mueller, B.D. (2007). "Koskinonodon Branson and Mehl, 1929, a replacement name for the preoccupied temnospondyl Buettneria Case, 1922". Journal of Vertebrate Paleontology. 27 (1): 225. doi:10.1671/0272-4634(2007)27[225:KBAMAR2.0.CO;2]. S2CID 85763026
  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.