Paleobiota of the Chinle Formation

Amniotes

Archosauromorphs

Archosaurs

Other Archosauromorphs

Misc. Archosauromorphs of the Chinle Formation
Genus	Species	State	Member	Abundance	Notes	Images
Crosbysaurus[1]	C. harrisae[1]	Arizona Utah [1]	Blue Mesa[1]		A archosauriform represented only by teeth.[1] It is treated as indeterminate archosauriform remains by Irmis in 2005.[1] It was originally thought to be an ornithischian dinosaur.	Crosbysaurus Trilophosaurus Vancleavea
Tanytrachelos[2]	Indeterminate[2]	Arizona[2]	Mesa Redondo[2]	Represented by a cervical rib.[2]	A tanystropheid represented by several hundred fossil specimens.
Tecovasaurus[3]	T. murryi[3]	Arizona[3]	Mesa Redondo[3]		An unknown amniote represented by scattered teeth formerly believed to be from an ornithischian dinosaur.[3] Later discoveries of similar teeth in pseudosuchians meant that these could no longer be regarded as anything more specific than some kind of archosauriform.[3]
Trilophosaurus[4]	T. buettneri[5]	Arizona[5]	Blue Mesa[5]
	T. dornorum[6]	Arizona[6]	Sonsela[6]
	T. jacobsi[7]	Arizona[7]	Blue Mesa[7] Mesa Redondo[7]
Vancleavea[8]	V. campi[8]	Arizona[8]	Petrified Forest[8] Sonsela[8] Blue Mesa[8]		A strange aquatic carnivore of uncertain affinities that is represented by both articulated skeletons and scattered elements like osteoderms and vertebrae.[8]

Other amniotes

Misc. Amniotes of the Chinle Formation
Genus	Species	State	Member	Abundance	Notes	Images
Acallosuchus[9]	A. rectori[9]	Arizona[9]	Blue Mesa[9]	Known only from a partial skull.[9]	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.[9]	Placerias
Colognathus[10]	C. obscurus[10]	Arizona[10]	Blue Mesa[10]	Known only from a jaw fragment and some isolated teeth.[10]	Originally believed to be a fish, Colognathus had distinct, fluted teeth.[10]
Kraterokheirodon[11]	K. colberti[11]	Arizona[11]	Petrified Forest[11] Blue Mesa or Mesa Redondo[11]	Known only from two teeth.[11]	Although they share some similarities with cynodont teeth, the known Kraterokheirodon teeth are very distinctive and can't be confidently referred to a known amniote group.[11]
Placerias[12]	P. hesternus[12]	Arizona[12]	Blue Mesa[12] Mesa Redondo[12]	Known from several hundred remains, but very rare outside of the highly concentrated Placerias Quarry.[12] It was likely uncommon in its ecosystem and the large numbers of specimens in the Placerias Quarry attributable to "taphonomic processes."[12]	A placeriine stahleckeriid
Uatchitodon[13]	U. schneideri[14]	Arizona[15]	Mesa Redondo[15]	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."[15]	An unknown reptile, probably a carnivorous archosauromorph.

Amphibians

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

Amphibians of the Chinle Formation
Genus	Species	State	Member	Abundance	Notes	Images
Apachesaurus[16]	A. gregorii[16]	Arizona[16]	Owl Rock[16] Petrified Forest[16] Blue Mesa[16]	Common in the Owl Rock and Petrified forest members.[16] Blue Mesa remains are fragmentary.[16]		Apachesaurus Koskinonodon
Koskinonodon[17]	K. perfecta[18]	Arizona[18]	Owl Rock[18] Petrified Forest[18] Sonsela[18] Blue Mesa[18] Mesa Redondo[18]	K. perfecta is "possibly the most common tetrapod fossil in the lower Chinle", although its presence in the upper Chinle is "unclear".[18]	The new genus Koskinonodon was erected for the species "Buettneria" perfecta when it was discovered that the latter genus was preoccupied.[17]

Cartilaginous fish

Chondrichthyans of the Chinle Formation
Genus	Species	State	Stratigraphic position	Abundance	Notes	Images
Acrodus[19]	Indeterminate[19]	Arizona[19]	Petrified Forest[20] Sonsela[20] Mesa Redondo[19]	Only a single tooth is known.[19]		Xenacanthus
Lonchidion[21]	L. humblei[21]	Arizona[21]	Blue Mesa[21] Mesa Redondo[21]		Lonchidion remains are common throughout the Carnian microvertebrate sites of the American southwest.[21]
Phoebodus[22]	Indeterminate[22]	Arizona[22]	Mesa Redondo[22]	Only a single specimen has been recovered from the formation.[22]
Reticulodus[23]	R. synergus[23]	Arizona[23]	Owl Rock[23] Petrified Forest[23] Sonsela[23]		The crown of its tooth bears a "reticulating ornamentation on [its] occlusal surface[.]"[23] Reticulodus remains are common throughout the Norian microvertebrate sites of the American southwest.[23]
Xenacanthus[24]	X. moorei[24]	Arizona[24]	Blue Mesa[24] Mesa Redondo[24]	Common in the lower Chinle Formation's microvertebrate localities.[24]

Lobe-finned fish

Coelacanths

Actinistians of the Chinle Formation
Genus	Species	State	Stratigraphic position	Abundance	Notes
Chinlea[25]	Indeterminate[26]	Arizona[26]	Owl Rock[26] Blue Mesa[26]			Chinlea

Lungfish

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

Dipnoans of the Chinle Formation
Genus	Species	State	Abundance	Notes	Notes
Arganodus[27]	A. dorotheae[27]
	Indeterminate[27]	Arizona[27]	Petrified Forest[27] Sonsela[27] Blue Mesa[27] Mesa Redondo[27]	Arganodus toothplates are the most common fossil in the formation from a non-tetrapod.[27] They are evenly distributed across strata, although some individual localities have very high concentrations.[27]	Most Chinlean Arganodus fossils are isolated tooth plates.[27]
Ceratodus[27]	C. dorotheae[27]				Named by Case in 1921, in the 1980s it was referred to Arganodus.[27]

Ray-finned fish

Actinopterygians of the Chinle Formation
Genus	Species	State	Stratigraphic position	Abundance	Notes	Images
Australosomus[28]	Indeterminate[29]	Arizona[29]	Mesa Redondo[29]	Known only from two vertebrae.[29]		Australosomus
Lasalichthyes[30]	Indeterminate[31]	Arizona[31]	Petrified Forest[31] Blue Mesa[31] Mesa Redondo[31]		Represented by isolated scales.[31]
Turseodus[32]	Indeterminate[33]	Arizona[33]	Owl Rock[33] Petrified Forest[33] Sonsela[33] Blue Mesa[33]	Common.[33]	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.[33]

Footnotes

1. "Vertebrate Fauna; Archosauriformes; Crosbysaurus harrisae," Irmis (2005) p. 71
2. "Vertebrate Fauna; Archosauromorpha; Tanytrachelos sp.," Irmis (2005) p. 70
3. "Vertebrate Fauna; Archosauriformes; Tecovasaurus murryi," Irmis (2005) p. 71
4. "Vertebrate Fauna; Archosauromorpha; Trilophosaurus buettneri, Trilophosaurus jacobsi, Trilophosaurus sp." Irmis (2005) p. 70
5. "Vertebrate Fauna; Archosauromorpha; Trilophosaurus buettneri," Irmis (2005) p. 70
6. "Abstract," Mueller and Parker (2006) p. 119
7. "Vertebrate Fauna; Archosauromorpha; Trilophosaurus jacobsi," Irmis (2005) p. 70
8. "Vertebrate Fauna; Archosauriformes; Vancleavea campi," Irmis (2005) p. 71
9. "Vertebrate Fauna; Reptilia incertae sedis; Acallosuchus rectori," Irmis (2005) pp. 69-70
10. "Vertebrate Fauna; Parareptilia; Colognathus obscurus," Irmis (2005) p. 69
11. "Vertebrate Fauna; Amniota incertae sedis; Kraterokheirodon colberti," Irmis (2005) p. 69
12. "Vertebrate Fauna; Synapsida; Placerias hesternus," Irmis (2005) p. 82
13. Listed as cf. Uatchitodon sp. in "Vertebrate Fauna; Reptilia incertae sedis; Cf. Uatchitodon sp," Irmis (2005) p. 69
14. Mitchell, J.S.; Heckert, A.B.; and Sues, H.-D. (2010). "Grooves to tubes: evolution of the venom delivery system in a Late Triassic "reptile"". Naturwissenschaften 97 (12): 1117–1121. doi:10.1007/s00114-010-0729-0. PMID 21060984.
15. "Vertebrate Fauna; Reptilia incertae sedis; Cf. Uatchitodon sp," Irmis (2005) p. 69
16. "Vertebrate Fauna; Temnospondyli; Apachesaurus gregorii" Irmis (2005) pp. 67-68
17. Mueller (2007)
18. "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.
19. "Vertebrate Fauna; Chondrichthyes; Acrodus sp." Irmis (2005) p. 65
20. The Petrified Forest and Sonsela Acrodus specimens are actually Reticulodus. See "Vertebrate Fauna; Chondrichthyes; Acrodus sp." Irmis (2005) p. 65 for details.
21. "Vertebrate Fauna; Chondrichthyes; Lonchidion humblei," Irmis (2005) p. 65
22. "Vertebrate Fauna; Chondrichthyes; Phoebodus sp." Irmis (2005) p. 65
23. "Vertebrate Fauna; Chondrichthyes; Reticulodus synergus," Irmis (2005) p. 65
24. "Vertebrate Fauna; Chondrichthyes; 'Xenacanthus' moorei," Irmis (2005) p. 64
25. Listed as cf. Chinlea sp. in "Vertebrate Fauna; Temnospondyli; Cf. Chinlea sp." Irmis (2005) p. 67
26. "Vertebrate Fauna; Temnospondyli; Cf. Chinlea sp." Irmis (2005) p. 67
27. "Vertebrate Fauna; Temnospondyli; Arganodus sp." Irmis (2005) p. 67
28. Listed as "cf. Australosomus" in "Vertebrate Fauna; Osteichthyes; Cf. Australosomus sp." Irmis (2005) p. 66-67
29. "Vertebrate Fauna; Osteichthyes; Cf. Australosomus sp." Irmis (2005) p. 66-67
30. Listed as "cf. Lasalichthyes" in "Vertebrate Fauna; Osteichthyes; Cf. Lasalichthyes sp." Irmis (2005) p. 66
31. "Vertebrate Fauna; Osteichthyes; Cf. Lasalichthyes sp." Irmis (2005) p. 66
32. Listed as "cf. Turseodus" in "Vertebrate Fauna; Osteichthyes; Cf. Turseodus sp." Irmis (2005) p. 66
33. "Vertebrate Fauna; Osteichthyes; Cf. Turseodus sp." Irmis (2005) p. 66

References

• 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:KBAMAR]2.0.CO;2.
• Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.