Kritosaurus
Kritosaurus | |
---|---|
K. navajovius AMNH
| |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | †Ornithischia |
Clade: | †Ornithopoda |
Family: | †Hadrosauridae |
Subfamily: | †Saurolophinae |
Tribe: | †Kritosaurini |
Genus: | †Kritosaurus Brown, 1910 |
Type species | |
†Kritosaurus navajovius Brown, 1910
| |
Species | |
†K. navajovius Brown, 1910 | |
Synonyms | |
Anasazisaurus? Hunt & Lucas, 1993 |
Kritosaurus is an incompletely known
History of discovery
In 1904, Barnum Brown discovered the type specimen (AMNH 5799) of Kritosaurus near the Ojo Alamo Formation, San Juan County, New Mexico, United States, while following up on a previous expedition.[2] He initially could not definitely correlate the stratigraphy, but by 1916 was able to establish it as from what is now known as the late Campanian-age De-na-zin Member of the Kirtland Formation.[3][4] When discovered, much of the front of the skull had either eroded or fragmented, and Brown reconstructed this portion after what is now called Edmontosaurus, leaving out many fragments.[2] However, he had noticed that something was different about the fragments, but ascribed the differences to crushing.[5] He initially wanted to name it Nectosaurus, but found out that this name was already in use; Jan Versluys, who had visited Brown before the change, inadvertently leaked the previous choice.[6] He kept the specific name, though, leading to the combination K. navajovius.
The 1914 publication of the arch-snouted Canadian genus Gryposaurus
By the late 1970s and early 1980s, Hadrosaurus had entered the discussion as a possible synonym of either Kritosaurus, Gryposaurus, or both, particularly in semi-technical "dinosaur dictionaries".[15][16] David B. Norman's The Illustrated Encyclopedia of Dinosaurs, uses Kritosaurus for the Canadian material (Gryposaurus), but identifies the mounted skeleton of K. incurvimanus as Hadrosaurus.[17]
The synonymization of Kritosaurus and Gryposaurus that lasted from the 1910s to 1990 led to a distorted picture of what the original Kritosaurus material represented. Because the Canadian material was much more complete, most representations and discussions of Kritosaurus from the 1920s to 1990 are actually more applicable to Gryposaurus. This includes, for example, James Hopson's discussion of hadrosaur cranial ornamentation,[18] and the adaptation of this for the public in The Illustrated Encyclopedia of Dinosaurs.[19]
Formerly assigned species and material
In 1984,
In 1990, Jack Horner and David B. Weishampel once again separated Gryposaurus, citing the uncertainty associated with the latter's partial skull. Horner in 1992 described two more skulls from New Mexico that he claimed belonged to Kritosaurus and showed that it was quite different from Gryposaurus,[23] but the following year Adrian Hunt and Spencer G. Lucas put each skull in its own genus, creating Anasazisaurus and Naashoibitosaurus.[24]
In 2002, specimen TxVP 41917-1, a partial left maxilla recovered from Bruja Canyon in Big Bend National Park, was assigned to Kritosaurus, as cf. K. navajovius. Twenty years later, it was discovered to contain a number of useful diagnostic traits that allow it to be described as a new taxon, and thus Malefica was named by Prieto-Márquez and Wagner (2023).[25]
Horner originally assigned the Anasazisaurus skull to Kritosaurus navajovius,[23] but Hunt and Lucas could not find any diagnostic features in the limited material of Kritosaurus and judged the genus to be a nomen dubium. Since the Anasazisaurus skull did have diagnostic features of its own, and did not appear to them to share any unique features with Kritosaurus, it was given the new name Anasazisaurus horneri,[24] an opinion which was supported by some later authors.[13] Not all authors have agreed with this, Thomas E. Williamson in particular defending Horner's original interpretation,[4] and several subsequent studies recognized both distinct genera.[26][29]
A comprehensive study of known Kritosaurus material published by Albert Prieto-Márquez in 2013 upheld the status of Naashoibitosaurus as a distinct genus, but found that the type specimens of Kritosaurus and Anasazisaurus were indistinguishable when comparing overlapping elements (i.e. only those bones preserved in both specimens). Prieto-Márquez therefore regarded Anasazisaurus as a synonym of Kritosaurus, but retained it as the distinct species K. horneri.[27]
A partial skeleton from the Sabinas Basin in Mexico was described as Kritosaurus sp. by Jim Kirkland and colleagues,[26] but considered an indeterminate saurolophine by Prieto-Márquez (2013).[27] This skeleton is about 20% larger than other known specimens, around 11 meters [36 ft] long, and with a distinctively curved ischium, and represents one of the largest known well-documented North American saurolophines. Unfortunately, the nasal bones are also incomplete in the skull remains from this material.[26] The informal name "Sabinosaurus" has been given to the specimen.[28]
A possibly second but confirmed to be valid species of Kritosaurus may have lived in the Javelina Formation alongside Kritosaurus navajovius.[30][31]
Description
The type specimen of Kritosaurus navajovius is only represented by a partial skull and lower jaws, and associated postcranial remains.[13] The greater portion of the muzzle and upper beak are missing.[26] However, these remains alone indicate a large body size, reaching 9 metres (30 ft) in length and 4 metric tons (4.4 short tons) in body mass.[32][33]
The length of the skull is estimated at 87 cm (34 in) from the tip of the upper beak to the base of the
According to Prieto-Márquez who re-diagnosed this genus in 2013, Kritosaurus can be distinguished based on the following characteristics: the length of the dorsolateral margin of the
Classification
Kritosaurus was a
The following is a cladogram based on the phylogenetic analysis conducted by Prieto-Márquez and Wagner in 2012, showing the relationships of Kritosaurus among the other Kritosaurini:[35]
Kritosaurini |
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Paleobiology
The nasal crest of Kritosaurus, whatever its true form, may have been used for a variety of social functions, such as identification of sexes or species and social ranking.[13] There may have been inflatable air sacs flanking it for both visual and auditory signaling.[18]
Diet and feeding
As a hadrosaurid, Kritosaurus would have been a large
Paleoecology
Kritosaurus was discovered in the De-na-zin Member of the Kirtland Formation. This formation dates from the late Campanian stages of the Late Cretaceous Period (74 to 70 million years ago),[4] and is also the source of several other dinosaurs, like Alamosaurus, a species of Parasaurolophus, Pentaceratops, Nodocephalosaurus, Saurornitholestes, and Bistahieversor.[36] The Kirtland Formation is interpreted as river floodplains appearing after a retreat of the Western Interior Seaway. Conifers were the dominant plants, and chasmosaurine horned dinosaurs appear to have been more common than hadrosaurids.[37] The presence of Parasaurolophus and Kritosaurus in northern latitude fossil sites may represent faunal exchange between otherwise distinct northern and southern biomes in Late Cretaceous North America.[38] Both taxa are uncommon outside of the southern biome, where, along with Pentaceratops, they are predominate members of the fauna.[38]
The geographic range of Kritosaurus remains in North America was expanded by the discovery of bones from the late Campanian-age Aguja Formation of Texas, including a skull,[39][40] although this specimen was given its own genus name, Aquilarhinus, in 2019.[41] Additionally, a partial skull from Coahuila, Mexico has been referred to K. navajovius.[27]
Since the 1910s and 1930s, Barnum Brown described that an unsubscribed species of Kritosaurus, the most likely candidate being Kritosaurus navajovius, had inhabited the late
However, confirmed Kritosaurus remains, possibly belonging to K. navajovius, cf. K. navajovius, and possibly a new species have been unearthed in the
.See also
References
- ISBN 978-0-253-34817-3.
- ^ hdl:2246/1398.
- ^ Gilmore, Charles W.(1916). "Contributions to the geology and paleontology of San Juan County, New Mexico. 2. Vertebrate faunas of the Ojo Alamo, Kirtland and Fruitland Formations". United States Geological Survey Professional Paper. 98-Q: 279–302.
- ^ a b c Williamson, Thomas E. (2000). "Review of Hadrosauridae (Dinosauria, Ornithischia) from the San Juan Basin, New Mexico". In Lucas, S.G.; Heckert A.B. (eds.). Dinosaurs of New Mexico. New Mexico Museum of Natural History and Science Bulletin, 17. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 191–213.
- ^ doi:10.1086/622336.
- ^ Olshevsky, George (1999-11-17). "Re: What are these dinosaurs? 2: Return of What are these dinosaurs?". Dinosaur Mailing List. Archived from the original on 2011-11-17. Retrieved 2007-06-15.
- ^ Lambe, Lawrence M. (1914). "On Gryposaurus notabilis, a new genus and species of trachodont dinosaur from the Belly River Formation of Alberta, with a description of the skull of Chasmosaurus belli". The Ottawa Naturalist. 27 (11): 145–155.
- hdl:2246/704.
- ^ Parks, William A. (1920). "The osteology of the trachodont dinosaur Kritosaurus incurvimanus". University of Toronto Studies, Geology Series. 11: 1–76.
- S2CID 83539808.
- ^ a b Lull, Richard Swann; Wright, Nelda E. (1942). Hadrosaurian Dinosaurs of North America. Geological Society of America Special Paper 40. Geological Society of America. pp. 164–172.
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- ^ ISBN 978-0-520-24209-8.
- ^ Prieto-Márquez, Alberto; Weishampel, David B.; Horner, John R. (2006). "The dinosaur Hadrosaurus foulkii, from the Campanian of the East Coast of North America, with a reevaluation of the genus" (PDF). Acta Palaeontologica Polonica. 51 (1): 77–98.
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- ^ Bonaparte, José; Franchi, M.R.; Powell, J.E.; Sepulveda, E. (1984). "La Formación Los Alamitos (Campaniano-Maastrichtiano) del sudeste de Rio Negro, con descripcion de Kritosaurus australis n. sp. (Hadrosauridae). Significado paleogeografico de los vertebrados". Revista de la Asociación Geológica Argentina (in Spanish). 39 (3–4): 284–299.
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- ^ a b c Horner, John R. (1992). "Cranial morphology of Prosaurolophus (Ornithischia: Hadrosauridae) with descriptions of two new hadrosaurid species and an evaluation of hadrosaurid phylogenetic relationships". Museum of the Rockies Occasional Paper. 2: 1–119.
- ^ a b c Hunt, Adrian P.; Lucas, Spencer G. (1993). "Cretaceous vertebrates of New Mexico". In Lucas, S.G.; Zidek J. (eds.). Dinosaurs of New Mexico. New Mexico Museum of Natural History and Science Bulletin, 2. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 77–91.
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- ^ a b c d e f g Kirkland, James I.; Hernández-Rivera, René; Gates, Terry; Paul, Gregory S.; Nesbitt, Sterling; Serrano-Brañas, Claudia Inés; Garcia-de la Garza, Juan Pablo (2006). "Large hadrosaurine dinosaurs from the latest Campanian of Coahuila, Mexico". In Lucas, S.G.; Sullivan Robert M. (eds.). Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin, 35. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 299–315.
- ^ S2CID 84942579.
- ^ (PDF) from the original on 27 April 2021.
- ^ a b Lucas, Spencer G.; Spielman, Justin A.; Sullivan, Robert M.; Hunt, Adrian P.; Gates, Terry (2006). "Anasazisaurus, a hadrosaurian dinosaur from the Upper Cretaceous of New Mexico". In Lucas, S.G.; Sullivan Robert M. (eds.). Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin, 35. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 293–297.
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- ^ Holtz, Thomas R. Jr. (2012). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages (PDF).
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- ^ Lull, Richard Swann; Wright, Nelda E. (1942). Hadrosaurian Dinosaurs of North America. Geological Society of America Special Paper 40. Geological Society of America. p. 226.
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- ^ Weishampel, David B.; Barrett, Paul M.; Coria, Rodolfo A.; Le Loeuff, Jean; Xu Xing; Zhao Xijin; Sahni, Ashok; Gomani, Elizabeth, M.P.; and Noto, Christopher R. (2004). "Dinosaur Distribution". The Dinosauria (2nd). 517–606.
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- ^ a b Lehman, T. M., 2001, Late Cretaceous dinosaur provinciality: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, pp. 310-328.
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- ^ a b Wagner, Jonathan R. (May 2001). The hadrosaurian dinosaurs (ornithiscia: hadrosauria) of Big Bend National Park, Brewster County, Texas, with implications for late Cretaceous paleozoogeography. Doctoral Dissertation, Texas Tech University (Thesis). Texas Tech University. Retrieved 16 November 2020.
- ^ ISBN 978-0-520-24209-8.
- ^ Gilmore, Charles Whitney (1916). "Vertebrate faunas of the Ojo Alamo, Kirtland and Fruitland formations" (PDF). Washington D.C.: US Government Printing Office: 280–302. Retrieved 17 November 2020.
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(help) - S2CID 128849169.
- )
- ^ Sullivan, Robert M. (2004). "THE KIRTLANDIAN LAND-VERTEBRATE "AGE"—LATE CRETACEOUS OF WESTERN NORTH AMERICA". Geological Society of America Abstracts with Programs. 36 (4).
- )
- . Retrieved 17 November 2020.
- ^ Jasinski, Steven E.; Sullivan, Robert M.; Lucas, Spencer G. (January 2011). "Taxonomic composition of the Alamo Wash local fauna from the Upper Cretaceous Ojo Alamo Formation (Naashoibito Member), San Juan Basin, New Mexico". Fossil Record. 3: 216–271. Retrieved 17 November 2020.
- ^ Williamson, Thomas W. (2000). Lucas, S. G.; Heckert, A. B. (eds.). "Review of Hadrosauridae (Dinosauria, Ornithischia) from the San Juan Basin, New Mexico." Dinosaurs of New Mexico". New Mexico Museum of Natural History and Science, Bulletin. 17. 1801 Mountain Rd NW, Albuquerque, NM 87104: New Mexico Museum of Natural History and Science: 191–213.
{{cite journal}}
: CS1 maint: location (link) - ^ S2CID 133329640. Retrieved 17 November 2020.
External links
- Media related to Kritosaurus at Wikimedia Commons