Kaiparowits Formation

The Kaiparowits Formation is a sedimentary rock formation found in the Kaiparowits Plateau in Grand Staircase-Escalante National Monument, in the southern part of Utah in the western United States. It is over 2800 feet (850 m) thick, and is Campanian in age. This Upper Cretaceous formation was formed from alluvial floodplains of large rivers in coastal southern Laramidia; sandstone beds are the deposit of rivers, and mudstone beds represent floodplain deposits. It is fossiliferous, with most specimens from the lower half of the formation, but exploration is only comparatively recent, with most work being done since 1982. It has been estimated that less than 10% of the Kaiparowits formation has been explored for fossils. Most fieldwork has been conducted by The Natural History Museum of Utah.

Kaiparowits Formation Stratigraphic range: Campanian 76.6–74.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Thickness	790 m (2,600 ft)
Lithology
Primary	Mudstone, sandstone
Location
Coordinates	37°24′0″N 111°41′0″W
Region	Utah
Country	USA

Age

Traditionally, the Kaiparowits Formation has been considered to be roughly equivalent in age to the northern Dinosaur Park Formation. This, combined with the differences in fauna between the two formations, has led some scientists, most notably Scott Sampson, to conclude that there was some kind of barrier separating northern and southern Laramidia at this time. However, preliminary re-calibration of late Cretaceous formation correlations suggests that the upper part of the Kaiparowits, where many of the unique species are found, is actually younger than the Dinosaur Park, and that some Kaiparowits species may in fact simply be descendants of Dinosaur Park species.[1]

According to this re-calibrated stratigraphic data, the Kaiparowits dates from about 76.6 to 74.5 million years ago.[2]

Biostratigraphy

The timeline below follows the re-calibrated timeline of Fowler (2016),[1] showing species from the Kaiparowits Formation in green, and related species from Alberta in blue.

Habitat

The Kaiparowits Formation is a muddy bed that was deposited between about 76.1 to 74.0 million years ago,[3] in the area where the Grand Staircase-Escalante National Monument of Utah is today. It is extremely fossil rich, with thousands of plants and animal fossils being preserved in amongst its sandstone and mudstone deposits. Based on plants remains including multiple vines, leaves, and branches, It was assumed by paleontologists Scott Sampson and his colleagues that Utah in the Campanian was a dense jungle bordering the Western Interior Seaway. The jungle theory would also support why almost all the animals in the Kaiparowits Formation were new species, and why the deposits were so plentiful. Without the need for herbivores to migrate to find food, and theropods to migrate after herbivores, a whole ecosystem could evolve secluded from interbreeding. The theory also supported why the dinosaurs adorned such features like the 15 horns of Kosmoceratops, they were for sexual selection.[4]

Paleofauna

A Kosmoceratops disturbed from its rest by a wandering Talos in Laramidia

Animals present include chondrichthyans (sharks and rays), gars, bowfin, sturgeons, frogs, salamanders, turtles, lizards, crocodilians (including Deinosuchus),[5] coelurosaurian theropods such as dromaeosaurids, troodontids, and Ornithomimus velox, armored dinosaurs, the duckbill Parasaurolophus cyrtocristatus, and a variety of early mammals including multituberculates, marsupials, and insectivorans.[6] Recent finds include large specimens of the duckbill Gryposaurus,[7] including the new species G. monumentensis,[7] and the first described remains of the oviraptorosaurian Hagryphus giganteus.[8]

Trace fossils are also known from the Kaiparowits, including an excellently preserved hadrosaur skin impression known from a recent analysis by Herrero and Farke.[9]

Turtles

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.

Turtles reported from the Kaiparowits Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Boremys[10]	B. grandis[10]				A baenid
Arvinachelys[11]	A. goldeni				A baenid, notable for its atypical nasal structure.
Denazinemys[11]	D. nodosoa		middle unit of the upper Kaiparowits Formation		A baenid
Neurankylus[11]	Two species[11]				A baenid
Thescelus[11]	int.[11]				A baenid
Compsemys[12]	C. victa [12]				A paracryptodiran
Adocus[10]	indet., possibly several species[10]				An adocid
Basilemys[12]	B. nobilis[12]				A possible member of Nanhsiungchelyidae. By far the largest native turtle at about 78 centimeters in length.
Helopanoplia[10]	indt.[10]				A softshell turtle

Neosuchians

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.

Crocodilians reported from the Kaiparowits Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Bernissartia[13]	B. sp'[13]				May not be Bernissartia proper, but a close cousin. It would extend the family's time range to the Campanian.	Bernissartia Brachychampsa Deinosuchus
Alligatoroid [14]	nov. gen.[14]				Is similar in form to Allognathosuchus.
Brachychampsa[14]	B. sp[14]				A new species yet to be described. Reached around 2 meters in length and is known from skull bones and a partial juvenile skeleton.
Caimanine[14]	nov. gen.[14]				Known from a lower jaw fragment. Is the oldest known true caiman found.
Deinosuchus	D. hatcheri[15]				A very large alligatoroid, almost 10 meters in length.
	D. riograndensis[16]				A very large alligatoroid, similar in size to D. hatcheri.
Goniopholid[14]	nov. gen.[14]				A new genus that exceeded 3 meters in length. Has a thin snout suited for piscivory.
Leidyosuchus[17]	L. sp'[17]				A new species known from a partial skeleton

Ornithischians

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.

Ornithischians reported from the Kaiparowits Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Akainacephalus[18]	A. johnsoni	Horse Mountain Gryposaur Quarry	Middle unit	Complete skull and tail club, several vertebrae, osteoderms, synsacrum, hind- and forelimb elements.	A species of ankylosaurine related to Nodocephalosaurus	Akainacephalus Gryposaurus Kosmoceratops Parasaurolophus cyrtocristatus being attacked by Teratophoneus Undescribed ornithopod Utahceratops
Gryposaurus[19]	G. monumentensis[19]				A kritosaurin saurolophine hadrosaur
Kosmoceratops[20]	K. richardsoni				A chasmosaurine ceratopsid
Nasutoceratops[21]	N. titusi		Middle unit		A centrosaurine ceratopsid
Parasaurolophus[22]	P. cyrtocristatus[22]				A parasaurolophin lambeosaurine hadrosaur
	nov. gen.[23]				A new species distinct from other Parasaurolophus species. Includes the specimen Baby Joe.
Utahceratops[20]	U. gettyi				A chasmosaurine ceratopsid

Theropods

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.

Theropods reported from the Kaiparowits Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Hagryphus[19]	H. giganteus[19]				A caenagnathine caenagnathid	Hagryphus Ornithomimus Talos Teratophoneus curriei
Mirarce[24]	M. eatoni				An avisaurid enantiornithine
Ornithomimus?[22][25]	O. velox[22][25]				Probably not referable to Ornithomimus.[25]
Paronychodon[26]	Indeterminate[26]
Ricardoestesia[27]	Indeterminate[27]
Talos[19]	T. sampsoni[19]				A troodont
Teratophoneus[28]	T. curriei				A tyrannosaurine tyrannosaurid

See also

• List of dinosaur-bearing rock formations

References

1. Fowler, D. (2016). A new correlation of the Cretaceous formations of the Western Interior of the United States, I: Santonian-Maastrichtian formations and dinosaur biostratigraphy. Peer J Preprints.
2. Roberts EM, Sampson SD, Deino AL, Bowring S, Buchwaldt R. The Kaiparowits Formation: a remarkable record of Late Cretaceous terrestrial environments, ecosystems and evolution in western North America. In: Titus AL, Loewen MA, editors. At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington, Indiana: Indiana University Press; 2013. p. 85–106.
3. Roberts, EM; Deino, AL; Chan, MA (2005). "40Ar/39Ar age of the Kaiparowits Formation, southern Utah, and correlation of contemporaneous Campanian strata and vertebrate faunas along the margin of the Western Interior Basin". Cretaceous Research. 26 (2): 307–318. doi:10.1016/j.cretres.2005.01.002.
4. Miller, P. (May 2014). "Digging Utah's Dinosaurs". National Geographic. 225 (5): 60–79.
5. "FIRST REPORT OF THE HYPER-GIANT CRETACEOUS CROCODYLIAN DEINOSUCHUS FROM UTAH". gsa.confex.com. Archived from the original on 2017-07-29. Retrieved 2016-03-27.
6. Eaton, Jeffrey G.; Cifelli, Richard L.; Hutchinson, J. Howard; Kirkland, James I.; Parrish, J. Michael (1999). "Cretaceous vertebrate faunas from the Kaiparowits Plateau, south-central Utah". In Gillete, David D. (ed.). Vertebrate Paleontology in Utah. Miscellaneous Publication 99-1. Salt Lake City: Utah Geological Survey. pp. 345–353. ISBN 978-1-55791-634-1.
7. Gates, Terry; Sampson, Scott (2006). "A new species of Gryposaurus (Dinosauria: Hadrosauridae) from the Upper Campanian Kaiparowits Formation of Utah". Journal of Vertebrate Paleontology. 26 (3, Suppl): 65A. doi:10.1080/02724634.2006.10010069.
8. Zanno, Lindsay E.; Sampson, Scott D. (2005). "A new oviraptorosaur (Theropoda; Maniraptora) from the Late Cretaceous (Campanian) of Utah". Journal of Vertebrate Paleontology. 25 (4): 897–904. doi:10.1671/0272-4634(2005)025[0897:ANOTMF]2.0.CO;2.
9. Herrero, Lucia; Farke, Andrew A (2010). "Hadrosaurid Dinosaur Skin Impressions from the Upper Cretaceous Kaiparowits Formation of Southern Utah, USA". PalArch's Journal of Vertebrate Palaeontology. 7 (2): 1–7.
10. Hutchison, J. Howard; Michael J. Knell; Donald B. Brinkman (2013). "Turtles from the Kaiparowits Formation, Utah". In Alan L. Titus, Mark A. Loewen (ed.). At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Indiana University Press. pp. 295–318. ISBN 978-0-253-00896-1.
11. Lively, Joshua R. (2015). "A new species of baenid turtle from the Kaiparowits Formation (Upper Cretaceous, Campanian) of southern Utah". Journal of Vertebrate Paleontology. 35 (6): e1009084. doi:10.1080/02724634.2015.1009084.
12. Bryant, Laurie J. (1989). "Systematic Paleontology". Non-dinosaurian lower vertebrates across the Cretaceous-Tertiary boundary in northeastern Montana. Volume 134 of University of California publications in geological sciences. University of California Press. pp. 10–58. ISBN 978-0-520-09735-3.
13. http://archive.li.suu.edu/docs/ms130/AR/eatonj.pdf
14. "Abstracts of Papers". Journal of Vertebrate Paleontology. 24: 1–139. 2004. doi:10.1080/02724634.2004.10010643.
15. Irmis, Randall B. (January 2013). "Crocodyliforms from the late cretaceous of grand staircase–escalante national monument and vicinity, Southern Utah, U.S.A". At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah: 424–444. Archived from the original on 2017-11-07. Retrieved 2017-11-03.
16. "First Report of the Hyper-Giant Cretaceous Crocodylian Deinosuchus from Utah". Archived from the original on 2017-07-29. Retrieved 2016-03-27.
17. Xu, Heendong A.; Woodward, Samuel J.; Henn, Madison M.; Farke, Andrew A. (2014-01-30). "Leidyosuchus (Crocodylia: Alligatoroidea) from the Upper Cretaceous Kaiparowits Formation (late Campanian) of Utah, USA". Paleobios. 30 (3).
18. Jelle P. Wiersma; Randall B. Irmis (2018). "A new southern Laramidian ankylosaurid, Akainacephalus johnsoni gen. et sp. nov., from the upper Campanian Kaiparowits Formation of southern Utah, USA". PeerJ. 6: e5016. doi:10.7717/peerj.5016. PMC 6063217. PMID 30065856.
19. Lindsay E. Zanno; David J. Varricchio; Patrick M. O'Connor; Alan L. Titus; Michael J. Knell (2011). "A new troodontid theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America". PLOS ONE. 6 (9): e24487. Bibcode:2011PLoSO...624487Z. doi:10.1371/journal.pone.0024487. PMC 3176273. PMID 21949721.
20. Sampson, S. D.; Loewen, M. A.; Farke, A. A.; Roberts, E. M.; Forster, C. A.; Smith, J. A.; Titus, A. L. (2010). Stepanova, Anna (ed.). "New Horned Dinosaurs from Utah Provide Evidence for Intracontinental Dinosaur Endemism". PLOS ONE. 5 (9): e12292. Bibcode:2010PLoSO...512292S. doi:10.1371/journal.pone.0012292. PMC 2929175. PMID 20877459.
21. Sampson, SD; Lund, EK; Loewen, MA; Farke, AA; Clayton, KE (2013). "A remarkable short-snouted horned dinosaur from the Late Cretaceous (late Campanian) of southern Laramidia". Proc R Soc B. 280 (1766): 20131186. doi:10.1098/rspb.2013.1186. PMC 3730592. PMID 23864598.
22. "3.1 Utah, United States; 12. Kaiparowits Formation," in Weishampel, et al. (2004). Pages 579-580.
23. http://vertpaleo.org/Annual-Meeting/Annual-Meeting-Home/SVP-2017-program-book.aspx
24. Jessie Atterholt; J. Howard Hutchison; Jingmai K. O’Connor (2018). "The most complete enantiornithine from North America and a phylogenetic analysis of the Avisauridae". PeerJ. 6: e5910. doi:10.7717/peerj.5910. PMC 6238772. PMID 30479894.
25. Zanno, L.E., Weirsma, J.P., Loewen, M.A., Sampson, S.D. and Getty, M.A. (2010). A preliminary report on the theropod dinosaur fauna of the late Campanian Kaiparowits Formation, Grand Staircase-Escalante National Monument, Utah." Learning from the Land Symposium: Geology and Paleontology. Washington, DC: Bureau of Land Management.
26. Listed as "cf. Paronychodon sp." in "3.1 Utah, United States; 12. Kaiparowits Formation," in Weishampel, et al. (2004). Page 579.
27. Listed as "cf. Ricardoestesia sp." in "3.1 Utah, United States; 12. Kaiparowits Formation," in Weishampel, et al. (2004). Page 579.
28. Thomas D. Carr; Thomas E. Williamson; Brooks B. Britt; Ken Stadtman (2011). "Evidence for high taxonomic and morphologic tyrannosauroid diversity in the Late Cretaceous (Late Campanian) of the American Southwest and a new short-skulled tyrannosaurid from the Kaiparowits formation of Utah". Naturwissenschaften. 98 (3): 241–246. Bibcode:2011NW.....98..241C. doi:10.1007/s00114-011-0762-7. PMID 21253683.

Bibliography

• Weishampel, David B.; Peter Dodson, and Halszka Osmólska (eds.). 2004. The Dinosauria, 2nd edition, 1–880. Berkeley: University of California Press. Accessed 2019-02-21. ISBN 0-520-24209-2