Acheroraptor: Difference between revisions

Acheroraptor; Temporal range: Late Cretaceous (Maastrichtian), 67.2–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	Casts of the holotype maxilla and referred dentary, National Museum of Natural History.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Pennaraptora
Clade:	Paraves
Family:	†Dromaeosauridae
Genus:	†Acheroraptor; Evans et al., 2013
Type species
	†Acheroraptor temertyorum; Evans et al., 2013

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Acheroraptor is an extinct genus of dromaeosaurid theropod dinosaur known from the latest Maastrichtian Hell Creek Formation of Montana, United States. It contains a single species, Acheroraptor temertyorum. A. temertyorum is one of the two geologically youngest known species of dromaeosaurids, the other being Dakotaraptor steini, which is also known from Hell Creek. A basal cousin of Velociraptor, Acheroraptor is known from upper and lower jaw material.

Discovery and naming

Known material

Acheroraptor was first described and named by David C. Evans, Derek W. Larson and Philip J. Currie in 2013 and the type species is Acheroraptor temertyorum. The generic name is derived from the Greek Ἀχέρων, Acheron, "underworld", in reference to the provenance from the Hell Creek Formation, and the Latin raptor, "thief". The specific name honours James and Louise Temerty, the chairman of Northland Power and the ROM Board of Governors and his wife, who have supported the museum for many years.^[1]

Acheroraptor is known from the holotype ROM 63777, a complete right maxilla with several maxillary teeth (some isolated), and from a referred dentary (lower jaw) ROM 63778, both housed at the Royal Ontario Museum, Canada. Both specimens were collected approximately four metres from one another, from the same mixed faunal bonebed that occurs in the upper part of the Hell Creek Formation of Montana, dating to the latest Maastrichtian stage of the Late Cretaceous, immediately prior to the Cretaceous–Paleogene extinction event. The holotype specimen was collected on August 28, 2009, by commercial fossil hunters, one of whom also collected the dentary several years later, and who were later able to provide detailed geographic data from GPS and photographs of the specimen in situ in the ground on the day of discovery. Both specimens were subsequently purchased by the Royal Ontario Museum from a private collector.^[1]

Classification

The phylogenetic position of Acheroraptor was explored by Evans et al. (2013) using several data matrices. Both specimens of Acheroraptor were coded as a single taxon into Turner et al. (2012) data matrix, an extensive phylogenetic analysis of theropods that focuses on maniraptorans. Acheroraptor was recovered as a member of the clade containing Eudromaeosauria and Microraptorinae, confirming its referral to the Dromaeosauridae, and possibly to Eudromaeosauria. Within that clade, however, most taxa were recovered in a large polytomy, due to the limited codings available for Acheroraptor.^[1]

Evans et al. (2013) also coded the specimens of Acheroraptor (together and separately) into an updated version of the smaller, dromaeosaur-specific dataset from Longrich and Currie (2009). Velociraptor osmolskae and Balaur bondoc were added, Itemirus was excluded (following its identification as a tyrannosauroid by Miyashita and Currie (2009)), and following Turner et al. (2012) the codings for Adasaurus mongoliensis were separated into these based on the holotype from the Nemegt Formation, and these based on IGM 100/23 from the Bayanshiree Formation. Several characters were also rescored and modified, and two maxillary characters were added to the matrix from Turner et al. (2012). This analysis yielded a more resolved topology, placing Acheroraptor in a relatively basal position within the Velociraptorinae, which was otherwise found to include only Asian dromaeosaurids. The cladogram below shows the phylogenetic position of Acheroraptor following this analysis.^[1]

Dromaeosauridae

Mahakala omnogovae

Unenlagiinae

Rahonavis ostromi

	Austroraptor cabazai

	Buitreraptor gonzalezorum

	Neuquenraptor argentinus

	Unenlagia paynemili

	Unenlagia comahuensis

A 2022 study of eudromaeosauria reclassified Acheroraptor as a derived member of Saurornitholestinae, with Atrociraptor as its sister taxon.^[2] Another study found support for Acheroraptor as a saurornitholestine, with Atrociraptor being recovered as its sister taxon again.^[3]

Paleoecology

Acheroraptor is the youngest species of dromaeosaurid, and is from the Hell Creek Formation.^[1] The Hell Creek Formation is from the time of the Cretaceous-Paleogene Extinction Event, and has been dated to 66 ± 0.07 million years ago.^[4] Many animals and plants have been found in the Hell Creek Formation,^[5] the discovery site of Acheroraptor. As it is known from the Tyrannosaurus-Triceratops fauna, Acheroraptor is the youngest dromaeosaurid, along with the much larger Dakotaraptor.^[1]^[6]

Evans et al. found that Acheroraptor was the only dromaeosaurid from the Hell Creek Formation. Common teeth previously referred to Dromaeosaurus and Saurornitholestes would then be considered Acheroraptor. Evans et al. also concluded that there was probably only one dromaeosaurid in the Hell Creek-Lance assemblage.^[1] In 2015, this view was disproven, with the description of Dakotaraptor, a far larger second dromaeosaur from the formation.^[6] Other non-dromaeosaurid theropods from the formation are tyrannosaurids, ornithomimids, troodontids,^[5] birds,^[7] and caenagnathids.^[8] The tyrannosaurids from the formation are Nanotyrannus and Tyrannosaurus, although the former might be a junior synonym of the latter. Among ornithomimids are the genera Struthiomimus as well as Ornithomimus,^[5] and "Orcomimus."^[9] The birds known from the formation are Avisaurus,^[5] Brodavis baileyi,^[10] and two unnamed hesperornithoforms, possibly Potamornis.^[7] Only three oviraptorosaurs are from the Hell Creek Formation, Anzu, Leptorhynchos^[8] and third and undescribed specimen, very similar to Gigantoraptor, from South Dakota. However, only fossilized foot prints were discovered as of 2016.^[11] The known troodontids from this formation include Troodon, Pectinodon, and Paronychodon. A single species of coelurosaur is known from similar fossil formations includes Richardoestesia.

Ornithischians are abundant in the Hell Creek Formation. The main groups of ornithischians are ankylosaurians, ornithopods, ceratopsians, and pachycephalosaurians. One ankylosaurian and two nodosaurians are known, Ankylosaurus, Denversaurus and possibly Edmontonia. Multiple genera of ceratopsians are known from the formation, the leptoceratopsid Leptoceratops and the chasmosaurines Nedoceratops, Torosaurus, Triceratops,^[5] and Tatankaceratops.^[12] Hadrosaurs are common in the Hell Creek Formation, and are known from multiple species of the ornithopod Thescelosaurus, and the hadrosaurids Edmontosaurus,^[5]^[13] and an undescribed genus similar to Parasaurolophus. Five pachycephalosaurians have been found in the Hell Creek Formation. Among them are the derived pachycephalosaurids Sphaerotholus, Stygimoloch,^[5] Dracorex,^[14] Pachycephalosaurus,^[5] and an undescribed specimen from North Dakota.

Mammals are plentiful in the Hell Creek Formation. Groups represented include multituberculates, metatherians, and eutherians. The multituberculates represented include Paracimexomys,^[15] the cimolomyids Paressonodon,^[16] Meniscoessus, Essonodon, Cimolomys, Cimolodon, and Cimexomys; and the neoplagiaulacids Mesodma, and Neoplagiaulax. The alphadontids Alphadon, Protalphodon, and Turgidodon, pediomyids Pediomys,^[15] Protolambda, and Leptalestes,^[17] the stagodontid Didelphodon,^[15] the deltatheridiid Nanocuris, the herpetotheriid Nortedelphys,^[16] and the glasbiid Glasbius all represent metatherians of the Hell Creek Formation. A few eutherians are known, being represented by Alostera,^[15] Protungulatum,^[17] the cimolestids Cimolestes and Batodon, the gypsonictopsid Gypsonictops, and the possible nyctitheriid Paranyctoides.^[15]

References

^ ^a ^b ^c ^d ^e ^f ^g Evans, D.C.; Larson, D.W.; Currie, P.J. (2013). "A new dromaeosaurid (Dinosauria: Theropoda) with Asian affinities from the latest Cretaceous of North America". Naturwissenschaften. 100 (11): 1041–9. Bibcode:2013NW....100.1041E. doi:10.1007/s00114-013-1107-5. PMID 24248432. S2CID 14978813.
^ Powers, Mark J.; Fabbri, Matteo; Doschak, Michael R.; Bhullar, Bhart-Anjan S.; Evans, David C.; Norell, Mark A.; Currie, Philip J. (2022). "A new hypothesis of eudromaeosaurian evolution: CT scans assist in testing and constructing morphological characters". Journal of Vertebrate Paleontology. 41 (5): e2010087. Bibcode:2021JVPal..41E0087P. doi:10.1080/02724634.2021.2010087. S2CID 247039404.
^ Jasinski, Steven E.; Sullivan, Robert M.; Carter, Aja M.; Johnson, Erynn H.; Dalman, Sebastian G.; Zariwala, Juned; Currie, Philip J. (2022-11-07). "Osteology and reassessment of Dineobellator notohesperus, a southern eudromaeosaur (Theropoda: Dromaeosauridae: Eudromaeosauria) from the latest Cretaceous of New Mexico". The Anatomical Record. 306 (7): 1712–1756. doi:10.1002/ar.25103. ISSN 1932-8486. PMID 36342817. S2CID 253382718.
^ Husson, D.E.; Galbrun, B.; Laskar, J.; Hinnov, L.A.; Thibault, N.; Gardin, S.; Locklair, R.E. (2011). "Astronomical calibration of the Maastrichtian (Late Cretaceous)". Earth and Planetary Science Letters. 305 (3–4): 328–340. Bibcode:2011E&PSL.305..328H. doi:10.1016/j.epsl.2011.03.008.
^ ^a ^b ^c ^d ^e ^f ^g ^h Weishampel, D.B.; Dodson, P.; Osmólska, H. (2004). The Dinosauria (2nd ed.). Berkeley, California: University of California Press. pp. 861. ISBN 0520242092.
^ ^a ^b DePalma, R.A.; Burnham, D.A.; Martin, L.D.; Larson, P.L.; Bakker, R.T. (2015). "The First Giant Raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation". Paleontological Contributions (14): 1–16. doi:10.17161/paleo.1808.18764. S2CID 17099603.
^ ^a ^b Longrich, N.R.; Tokaryk, T.; Field, D.J. (2011). "Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary". Proceedings of the National Academy of Sciences. 108 (37): 15253–15257. Bibcode:2011PNAS..10815253L. doi:10.1073/pnas.1110395108. PMC 3174646. PMID 21914849.
^ ^a ^b Lamanna, M.C.; Sues, H.D.; Schachner, E.R.; Lyson, T.R. (2014). "A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America". PLOS ONE. 9 (3): e92022. Bibcode:2014PLoSO...992022L. doi:10.1371/journal.pone.0092022. PMC 3960162. PMID 24647078.
^ Triebold, M. (1997). "The Sandy site: Small dinosaurs from the Hell Creek Formation of South Dakota". In Wolberg, D.; Stump, E.; Rosenberg, G. (eds.). Dinofest International: Proceedings of a Symposium Sponsored by Arizona State University Academy of Natural Science. pp. 245–248.
^ Martin, L.D.; Kurochkin, E.N.; Tokaryk, T.T. (2012). "A new evolutionary lineage of diving birds from the Late Cretaceous of North America and Asia". Palaeoworld. 21: 59–63. doi:10.1016/j.palwor.2012.02.005.
^ Maltese, A. (17 December 2013). "Giant Oviraptor Tracks from the Hell Creek". RMDRC paleo lab. Blogspot. Retrieved 17 December 2013.
^ Ott, C.J.; Larson, P.L. (2010). "A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description". In Ryan, M.J.; Chinnery-Allgeier, B.J.; Eberth, D.A. (eds.). New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Bloomington: Indiana University Press. p. 656. ISBN 9780253353580.
^ Campione, N.S.E.; Evans, D.C. (2011). "Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America". PLOS ONE. 6 (9): e25186. Bibcode:2011PLoSO...625186C. doi:10.1371/journal.pone.0025186. PMC 3182183. PMID 21969872.
^ Bakker, R.T.; Sullivan, R.M.; Porter, V.; Larson, P.; Saulsbury, S.J. (2006). "Dracorex hogwartsia, n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota". In Lucas, S.G.; Sullivan, R.M. (eds.). Late Cretaceous vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin. Vol. 35. pp. 331–345.
^ ^a ^b ^c ^d ^e Kielan-Jaworowska, Z.; Cifelli, R.; Luo, Z-X. (2004). Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure. New York: Columbia University Press. ISBN 9780231119184. OCLC 61160163.
^ ^a ^b Wilson, G.P. (2013). "Mammals across the K/Pg boundary in northeastern Montana, U.S.A.: Dental morphology and body-size patterns reveal extinction selectivity and immigrant-fueled ecospace filling". Paleobiology. 39 (3): 429–469. Bibcode:2013Pbio...39..429W. doi:10.1666/12041. S2CID 36025237.
^ ^a ^b Archibald, J.D.; Zhang, Y.; Harper, T.; Cifelli, R.L. (2011). "Protungulatum, Confirmed Cretaceous Occurrence of an Otherwise Paleocene Eutherian (Placental?) Mammal". Journal of Mammalian Evolution. 18 (3): 153–161. doi:10.1007/s10914-011-9162-1. S2CID 16724836.

[Acheroraptor-1] ^ ^a ^b ^c ^d ^e ^f ^g Evans, D.C.; Larson, D.W.; Currie, P.J. (2013). "A new dromaeosaurid (Dinosauria: Theropoda) with Asian affinities from the latest Cretaceous of North America". Naturwissenschaften. 100 (11): 1041–9. Bibcode:2013NW....100.1041E. doi:10.1007/s00114-013-1107-5. PMID 24248432. S2CID 14978813.

[2] Powers, Mark J.; Fabbri, Matteo; Doschak, Michael R.; Bhullar, Bhart-Anjan S.; Evans, David C.; Norell, Mark A.; Currie, Philip J. (2022). "A new hypothesis of eudromaeosaurian evolution: CT scans assist in testing and constructing morphological characters". Journal of Vertebrate Paleontology. 41 (5): e2010087. Bibcode:2021JVPal..41E0087P. doi:10.1080/02724634.2021.2010087. S2CID 247039404.

[3] Jasinski, Steven E.; Sullivan, Robert M.; Carter, Aja M.; Johnson, Erynn H.; Dalman, Sebastian G.; Zariwala, Juned; Currie, Philip J. (2022-11-07). "Osteology and reassessment of Dineobellator notohesperus, a southern eudromaeosaur (Theropoda: Dromaeosauridae: Eudromaeosauria) from the latest Cretaceous of New Mexico". The Anatomical Record. 306 (7): 1712–1756. doi:10.1002/ar.25103. ISSN 1932-8486. PMID 36342817. S2CID 253382718.

[hcfage-4] Husson, D.E.; Galbrun, B.; Laskar, J.; Hinnov, L.A.; Thibault, N.; Gardin, S.; Locklair, R.E. (2011). "Astronomical calibration of the Maastrichtian (Late Cretaceous)". Earth and Planetary Science Letters. 305 (3–4): 328–340. Bibcode:2011E&PSL.305..328H. doi:10.1016/j.epsl.2011.03.008.

[weishampel-5] ^ ^a ^b ^c ^d ^e ^f ^g ^h Weishampel, D.B.; Dodson, P.; Osmólska, H. (2004). The Dinosauria (2nd ed.). Berkeley, California: University of California Press. pp. 861. ISBN 0520242092.

[DePalmaetal-6] DePalma, R.A.; Burnham, D.A.; Martin, L.D.; Larson, P.L.; Bakker, R.T. (2015). "The First Giant Raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation". Paleontological Contributions (14): 1–16. doi:10.17161/paleo.1808.18764. S2CID 17099603.

[pnas-7] Longrich, N.R.; Tokaryk, T.; Field, D.J. (2011). "Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary". Proceedings of the National Academy of Sciences. 108 (37): 15253–15257. Bibcode:2011PNAS..10815253L. doi:10.1073/pnas.1110395108. PMC 3174646. PMID 21914849.

[Anzu-8] Lamanna, M.C.; Sues, H.D.; Schachner, E.R.; Lyson, T.R. (2014). "A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America". PLOS ONE. 9 (3): e92022. Bibcode:2014PLoSO...992022L. doi:10.1371/journal.pone.0092022. PMC 3960162. PMID 24647078.

[tb1997-9] Triebold, M. (1997). "The Sandy site: Small dinosaurs from the Hell Creek Formation of South Dakota". In Wolberg, D.; Stump, E.; Rosenberg, G. (eds.). Dinofest International: Proceedings of a Symposium Sponsored by Arizona State University Academy of Natural Science. pp. 245–248.

[brodavis-10] Martin, L.D.; Kurochkin, E.N.; Tokaryk, T.T. (2012). "A new evolutionary lineage of diving birds from the Late Cretaceous of North America and Asia". Palaeoworld. 21: 59–63. doi:10.1016/j.palwor.2012.02.005.

[http://rmdrc.blogspot.com/2013/12/giant-oviraptor-tracks-from-hell-creek.html-11] Maltese, A. (17 December 2013). "Giant Oviraptor Tracks from the Hell Creek". RMDRC paleo lab. Blogspot. Retrieved 17 December 2013.

[tatanka-12] Ott, C.J.; Larson, P.L. (2010). "A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description". In Ryan, M.J.; Chinnery-Allgeier, B.J.; Eberth, D.A. (eds.). New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium. Bloomington: Indiana University Press. p. 656. ISBN 9780253353580.

[hcfhadro-13] Campione, N.S.E.; Evans, D.C. (2011). "Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America". PLOS ONE. 6 (9): e25186. Bibcode:2011PLoSO...625186C. doi:10.1371/journal.pone.0025186. PMC 3182183. PMID 21969872.

[bakker-14] Bakker, R.T.; Sullivan, R.M.; Porter, V.; Larson, P.; Saulsbury, S.J. (2006). "Dracorex hogwartsia, n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota". In Lucas, S.G.; Sullivan, R.M. (eds.). Late Cretaceous vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin. Vol. 35. pp. 331–345.

[:0-15] Kielan-Jaworowska, Z.; Cifelli, R.; Luo, Z-X. (2004). Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure. New York: Columbia University Press. ISBN 9780231119184. OCLC 61160163.

[mammal-16] Wilson, G.P. (2013). "Mammals across the K/Pg boundary in northeastern Montana, U.S.A.: Dental morphology and body-size patterns reveal extinction selectivity and immigrant-fueled ecospace filling". Paleobiology. 39 (3): 429–469. Bibcode:2013Pbio...39..429W. doi:10.1666/12041. S2CID 36025237.

[mammalshcf-17] Archibald, J.D.; Zhang, Y.; Harper, T.; Cifelli, R.L. (2011). "Protungulatum, Confirmed Cretaceous Occurrence of an Otherwise Paleocene Eutherian (Placental?) Mammal". Journal of Mammalian Evolution. 18 (3): 153–161. doi:10.1007/s10914-011-9162-1. S2CID 16724836.

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@@ Line 1: / Line 1: @@
-{{for|the similar-named illegal fossil forgery|Archaeoraptor}}
 {{Short description|Dromaeosaurid dinosaur genus from the Late Cretaceous}}
+{{For|the similar-named illegal fossil hoax|Archaeoraptor}}
 {{Automatic taxobox
 | fossil_range = [[Late Cretaceous]] ([[Maastrichtian]]), {{fossilrange|67.2|66}}
@@ Line 15: / Line 15: @@
 }}
-'''''Acheroraptor''''' is an [[extinct]] [[genus]] of [[dromaeosaurid]] [[theropod]] [[dinosaur]] known from the latest [[Maastrichtian]] [[Hell Creek Formation]] of [[Montana]], United States. It contains a single species, '''''Acheroraptor temertyorum'''''. ''A. temertyorum'' is one of the two geologically youngest known species of dromaeosaurids, the other being ''[[Dakotaraptor]]'', which is also known from Hell Creek. A basal cousin of ''Velociraptor'', ''Acheroraptor'' is known from upper and lower jaw material.
+'''''Acheroraptor''''' is an [[extinct]] [[genus]] of [[dromaeosaurid]] [[theropod]] [[dinosaur]] known from the latest [[Maastrichtian]] [[Hell Creek Formation]] of [[Montana]], United States. It contains a single species, '''''Acheroraptor temertyorum'''''. ''A. temertyorum'' is one of the two geologically youngest known species of dromaeosaurids, the other being ''[[Dakotaraptor steini]]'', which is also known from Hell Creek. A basal cousin of [[Velociraptor]], ''Acheroraptor'' is known from upper and lower jaw material.
 == Discovery and naming ==
@@ Line 27: / Line 27: @@
 The [[phylogenetic]] position of ''Acheroraptor'' was explored by Evans ''et al.'' (2013) using several data matrices. Both specimens of ''Acheroraptor'' were coded as a single taxon into Turner ''et al.'' (2012) data matrix, an extensive phylogenetic analysis of theropods that focuses on [[maniraptora]]ns. ''Acheroraptor'' was recovered as a member of the clade containing [[Eudromaeosauria]] and [[Microraptorinae]], confirming its referral to the [[Dromaeosauridae]], and possibly to Eudromaeosauria. Within that clade, however, most taxa were recovered in a large [[polytomy]], due to the limited codings available for ''Acheroraptor''.<ref name=Acheroraptor />
-Evans ''et al.'' (2013) also coded the specimens of ''Acheroraptor'' (together and separately) into an updated version of the smaller, dromaeosaur-specific dataset from Longrich and Currie (2009). ''[[Velociraptor osmolskae]]'' and ''[[Balaur bondoc]]'' were added, ''[[Itemirus]]'' was excluded (following its identification as a [[tyrannosauroid]] by Miyashita and Currie (2009)), and following Turner ''et al.'' (2012) the codings for ''[[Adasaurus mongoliensis]]'' were separated into these based on the holotype from the [[Nemegt Formation]], and these based on IGN 100/23 from the [[Bayanshiree Formation]]. Several characters were also rescored and modified, and two maxillary characters were added to the matrix from Turner ''et al.'' (2012). This analysis yielded a more resolved topology, placing ''Acheroraptor'' in a relatively [[basal (phylogenetics)|basal]] position within the [[Velociraptorinae]], which was otherwise found to include only Asian dromaeosaurids. The [[cladogram]] below shows the phylogenetic position of ''Acheroraptor'' following this analysis.<ref name=Acheroraptor />
+Evans ''et al.'' (2013) also coded the specimens of ''Acheroraptor'' (together and separately) into an updated version of the smaller, dromaeosaur-specific dataset from Longrich and Currie (2009). ''[[Velociraptor osmolskae]]'' and ''[[Balaur bondoc]]'' were added, ''[[Itemirus]]'' was excluded (following its identification as a [[tyrannosauroid]] by Miyashita and Currie (2009)), and following Turner ''et al.'' (2012) the codings for ''[[Adasaurus mongoliensis]]'' were separated into these based on the holotype from the [[Nemegt Formation]], and these based on IGM 100/23 from the [[Bayanshiree Formation]]. Several characters were also rescored and modified, and two maxillary characters were added to the matrix from Turner ''et al.'' (2012). This analysis yielded a more resolved topology, placing ''Acheroraptor'' in a relatively [[basal (phylogenetics)|basal]] position within the [[Velociraptorinae]], which was otherwise found to include only Asian dromaeosaurids. The [[cladogram]] below shows the phylogenetic position of ''Acheroraptor'' following this analysis.<ref name=Acheroraptor />
 {{clade| style=font-size:85%;line-height:85%
-|label1=[[Dromaeosauridae]]&nbsp;
+|label1=[[Dromaeosauridae]]
 |1={{clade
-   |1=''[[Mahakala omnogovae]]''
+   |1=''[[Mahakala omnogovae]]''<div style="{{MirrorH}}">[[File:Mahakala omnogovae no background.png|70px]]</div>
-   |label2=&nbsp;[[Unenlagiinae]]&nbsp;
+   |label2=[[Unenlagiinae]]
    |2={{clade
-      |1=''[[Rahonavis ostromi]]''
+      |1=''[[Rahonavis ostromi]]''<div style="{{MirrorH}}">[[File:Rahonavis NT.jpg|80px]]</div>
       |2={{clade
-         |1=''[[Austroraptor cabazai]]''
+         |1=''[[Austroraptor cabazai]]''<div style="{{MirrorH}}">[[File:Austroraptor Restoration.png|80px]]</div>
-         |2=''[[Buitreraptor gonzalezorum]]''
+         |2=''[[Buitreraptor gonzalezorum]]''<div style="{{MirrorH}}">[[File:Buitreraptor gonzalezorum.jpg|80px]]</div>
-         |3=''[[Neuquenraptor argentinus]]''
+         |3=''[[Neuquenraptor argentinus]]''<div style="{{MirrorH}}">[[File:Neuquenraptor argentinus by PaleoGeek.png|80px]]</div>
          |4=''[[Unenlagia paynemili]]''
-         |5=''[[Unenlagia comahuensis]]''}} }}
+         |5=''[[Unenlagia comahuensis]]'' <div style="{{MirrorH}}">[[File:Unenlagia comahuensis .jpg|80px]]</div>}} }}
    |3={{clade
-      |label1=&nbsp;[[Microraptoria]]&nbsp;
+      |label1=[[Microraptoria]]
       |1={{clade
-         |1=''[[Graciliraptor lujiatunensis]]''
+         |1=''[[Graciliraptor lujiatunensis]]''<div style="{{MirrorH}}">[[File:Graciliraptor.jpg|80px]]</div>
          |2=''[[Hesperonychus elizabethae]]''
-         |3=''[[Microraptor]]''
+         |3=''[[Microraptor]]''<div style="{{MirrorH}}">[[File:Microraptor Restoration.png|80px]]</div>
-         |4=''[[Shanag ashile]]''
+         |4=''[[Shanag ashile]]'' <div style="{{MirrorH}}">[[File:Shanag.jpg|80px]]</div>
-         |5=''[[Sinornithosaurus millenii]]''}}
+         |5=''[[Sinornithosaurus millenii]]''<div style="{{MirrorH}}">[[File:Sinornithosaurus.jpg|80px]]</div>}}
-      |label2=&nbsp;[[Eudromaeosauria]]&nbsp;
+      |label2=[[Eudromaeosauria]]
       |2={{clade
          |1={{clade
-            |1=''[[Bambiraptor feinbergi]]''
+            |1=''[[Bambiraptor feinbergi]]''<div style="{{MirrorH}}">[[File:Bambiraptor reconstruction.jpg|80px]]</div>
-            |2=''[[Saurornitholestes langstoni]]''}}
+            |2=''[[Saurornitholestes langstoni]]''<div style="{{MirrorH}}">[[File:Saurornitholestes langstoni skeletal.png|80px]]</div>}}
          |2={{clade
             |1={{clade
-               |1=''[[Atrociraptor marshalli]]''
+               |1=''[[Atrociraptor marshalli]]''<div style="{{MirrorH}}">[[File:Atrociraptor.jpg|80px]]</div>
-               |2=''[[Deinonychus antirrhopus]]''}}
+               |2=''[[Deinonychus antirrhopus]]''<div style="{{MirrorH}}">[[File:Deinonychus Restoration.png|80px]]</div>}}
             |2={{clade
-               |label1=&nbsp;[[Dromaeosaurinae]]&nbsp;
+               |label1=[[Dromaeosaurinae]]
                |1={{clade
-                  |1=''[[Achillobator giganticus]]''
+                  |1=''[[Achillobator giganticus]]''<div style="{{MirrorH}}">[[File:Achillobator reconstruction.png|80px]]</div>
-                  |2=''[[Dromaeosaurus albertensis]]''
+                  |2=''[[Balaur bondoc]]''<div style="{{MirrorH}}">[[File:Balaur by Mark P. Witton.png|80px]]</div>
-                  |3=''[[Dakotaraptor|Dakotaraptor steini]]''
+                  |3=''[[Dromaeosaurus albertensis]]''<div style="{{MirrorH}}">[[File:Dromaeosaurus Restoration.png|80px]]</div>
-                  |4=''[[Utahraptor ostrommaysorum]]''}}
+                  |4=''[[Dakotaraptor steini]]''<div style="{{MirrorH}}">[[File:Dakotaraptor Skeleton Reconstruction.jpg|80px]]</div>
+                  |5=''[[Utahraptor ostrommaysorum]]''<div style="{{MirrorH}}">[[File:Utahraptor Restoration.png|80px]]</div>}}
-              |label2=&nbsp;[[Velociraptorinae]]&nbsp;
+               |label2=[[Velociraptorinae]]
                |2={{clade
-                  |1=IGM 100/23= ?[[Adasaurus]]
+                  |1=''[[Acheroraptor temertyorum]]''<div style="{{MirrorH}}">[[File:Holotype ROM 63777.jpg|80px]]</div>
                   |2={{clade
-                     |1='''''Acheroraptor temertyorum'''''
+                        |1=''[[Velociraptor mongoliensis]]''<div style="{{MirrorH}}">[[File:Velociraptor Restoration.png|80px]]</div>
-                     |2={{clade
-                        |1=''[[Velociraptor mongoliensis]]''
                         |2={{clade
-                           |1=''[[Adasaurus mongoliensis]]''
+                           |1=''[[Adasaurus mongoliensis]]''<div style="{{MirrorH}}">[[File:Adasaurus Restoration.jpg|80px]]</div>
-                           |2=''[[Tsaagan mangas]]''
+                           |2=''[[Tsaagan mangas]]''<div style="{{MirrorH}}">[[File:Tsaagan.png|80px]]</div>
-                           |3=''[[Velociraptor osmolskae]]'' }} }} }} }} }} }} }} }} }} }}
+                           |3=''[[Velociraptor osmolskae]]''}} }} }} }} }} }} }} }} }}
-A 2022 study of eudromaeosauria reclassified ''Acheroraptor'' as a derived member of [[saurornitholestinae]]. The same study also classified ''Atrociraptor'' as a derived saurornitholestine and ''[[Deinonychus]]'' as a basal eudromaeosaur.<ref>{{Cite journal|url=https://www.tandfonline.com/doi/abs/10.1080/02724634.2021.2010087?journalCode=ujvp20#.YhPHvcpTPBM|doi = 10.1080/02724634.2021.2010087|title = A new hypothesis of eudromaeosaurian evolution: CT scans assist in testing and constructing morphological characters|year = 2022|last1 = Powers|first1 = Mark J.|last2 = Fabbri|first2 = Matteo|last3 = Doschak|first3 = Michael R.|last4 = Bhullar|first4 = Bhart-Anjan S.|last5 = Evans|first5 = David C.|last6 = Norell|first6 = Mark A.|last7 = Currie|first7 = Philip J.|journal = Journal of Vertebrate Paleontology|pages = e2010087|s2cid = 247039404}}</ref>
+A 2022 study of eudromaeosauria reclassified ''Acheroraptor'' as a derived member of [[Saurornitholestinae]], with ''[[Atrociraptor]]'' as its sister taxon.<ref>{{Cite journal|url=https://www.tandfonline.com/doi/abs/10.1080/02724634.2021.2010087?journalCode=ujvp20#.YhPHvcpTPBM|doi = 10.1080/02724634.2021.2010087|title = A new hypothesis of eudromaeosaurian evolution: CT scans assist in testing and constructing morphological characters|year = 2022|last1 = Powers|first1 = Mark J.|last2 = Fabbri|first2 = Matteo|last3 = Doschak|first3 = Michael R.|last4 = Bhullar|first4 = Bhart-Anjan S.|last5 = Evans|first5 = David C.|last6 = Norell|first6 = Mark A.|last7 = Currie|first7 = Philip J.|journal = Journal of Vertebrate Paleontology| volume=41 | issue=5 |pages = e2010087| bibcode=2021JVPal..41E0087P |s2cid = 247039404}}</ref> Another study found support for ''Acheroraptor'' as a saurornitholestine, with ''Atrociraptor'' being recovered as its sister taxon again.<ref>{{Cite journal |last1=Jasinski |first1=Steven E. |last2=Sullivan |first2=Robert M. |last3=Carter |first3=Aja M. |last4=Johnson |first4=Erynn H. |last5=Dalman |first5=Sebastian G. |last6=Zariwala |first6=Juned |last7=Currie |first7=Philip J. |date=2022-11-07 |title=Osteology and reassessment of ''Dineobellator notohesperus'', a southern eudromaeosaur (Theropoda: Dromaeosauridae: Eudromaeosauria) from the latest Cretaceous of New Mexico |url=https://onlinelibrary.wiley.com/doi/10.1002/ar.25103 |journal=The Anatomical Record |volume=306 |issue=7 |language=en |pages=1712–1756 |doi=10.1002/ar.25103 |pmid=36342817 |s2cid=253382718 |issn=1932-8486|url-access=subscription }}</ref>
 == Paleoecology ==
@@ Line 84: / Line 83: @@
 ''Acheroraptor'' is the youngest species of dromaeosaurid, and is from the Hell Creek Formation.<ref name="Acheroraptor">{{Cite journal|last1=Evans|first1=D.C.|last2=Larson|first2=D.W.|last3=Currie|first3=P.J.|date=2013|title=A new dromaeosaurid (Dinosauria: Theropoda) with Asian affinities from the latest Cretaceous of North America|journal=Naturwissenschaften|volume=100|issue=11|pages=1041–9|doi=10.1007/s00114-013-1107-5|pmid=24248432|bibcode=2013NW....100.1041E|s2cid=14978813}}</ref> The Hell Creek Formation is from the time of the [[Cretaceous-Paleogene Extinction Event]], and has been dated to 66 ± 0.07 million years ago.<ref name="hcfage">{{Cite journal|last1=Husson|first1=D.E.|last2=Galbrun|first2=B.|last3=Laskar|first3=J.|last4=Hinnov|first4=L.A.|last5=Thibault|first5=N.|last6=Gardin|first6=S.|last7=Locklair|first7=R.E.|date=2011|title=Astronomical calibration of the Maastrichtian (Late Cretaceous)|journal=Earth and Planetary Science Letters|volume=305|issue=3–4|pages=328–340|bibcode=2011E&PSL.305..328H|doi=10.1016/j.epsl.2011.03.008}}</ref> Many animals and plants have been found in the Hell Creek Formation,<ref name="weishampel" /> the discovery site of ''Acheroraptor''. As it is known from the ''[[Tyrannosaurus]]''-''[[Triceratops]]'' fauna, ''Acheroraptor'' is the youngest dromaeosaurid, along with the much larger ''[[Dakotaraptor]]''.<ref name=Acheroraptor /><ref name="DePalmaetal" />
-Evans ''et al.'' found that ''Acheroraptor'' was the only dromaeosaurid from the Hell Creek Formation. Common teeth previously referred to ''[[Dromaeosaurus]]'' and ''[[Saurornitholestes]]'' would then be considered ''Acheroraptor''. Evans ''et al.'' also concluded that there was probably only one dromaeosaurid in the Hell Creek-Lance assemblage.<ref name=Acheroraptor /> In 2015, this view was disproven, with the description of ''[[Dakotaraptor]]'', a far larger second dromaeosaur from the formation.<ref name="DePalmaetal">{{cite journal|last1=DePalma|first1=R.A.|last2=Burnham|first2=D.A.|last3=Martin|first3=L.D.|last4=Larson|first4=P.L.|last5=Bakker|first5=R.T.|date=2015|title=The First Giant Raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation|url=https://kuscholarworks.ku.edu/handle/1808/18764|journal=Paleontological Contributions|issue=14|pages=1–16|doi=10.17161/paleo.1808.18764|s2cid=17099603}}</ref> Other non-dromaeosaurid theropods from the formation are [[tyrannosauridae|tyrannosaurids]], [[ornithomimidae|ornithomimids]], [[troodontidae|troodontids]],<ref name="weishampel">{{cite book|last1=Weishampel|first1=D.B.|title=The Dinosauria|url=https://archive.org/details/dinosauriandedit00weis|url-access=limited|last2=Dodson|first2=P.|last3=Osmólska|first3=H.|publisher=University of California Press|year=2004|isbn=0520242092|edition=2nd|location=Berkeley, California|pages=[https://archive.org/details/dinosauriandedit00weis/page/n879 861]}}</ref> [[birds]],<ref name="pnas">{{Cite journal|last1=Longrich|first1=N.R.|last2=Tokaryk|first2=T.|last3=Field|first3=D.J.|date=2011|title=Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary|journal=Proceedings of the National Academy of Sciences|volume=108|issue=37|pages=15253–15257|bibcode=2011PNAS..10815253L|doi=10.1073/pnas.1110395108|pmc=3174646|pmid=21914849|doi-access=free}}</ref> and [[caenagnathidae|caenagnathids]].<ref name="Anzu">{{Cite journal|last1=Lamanna|first1=M.C.|last2=Sues|first2=H.D.|last3=Schachner|first3=E.R.|last4=Lyson|first4=T.R.|date=2014|title=A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America|journal=PLOS ONE|volume=9|issue=3|pages=e92022|doi=10.1371/journal.pone.0092022|pmc=3960162|pmid=24647078|bibcode=2014PLoSO...992022L|doi-access=free}}</ref> The tyrannosaurids from the formation are ''[[Nanotyrannus]]'' and ''Tyrannosaurus'', although the former might be a junior synonym of the latter. Among ornithomimids are the genera ''[[Struthiomimus]]'' as well as ''[[Ornithomimus]]'',<ref name="weishampel" /> and "[[Orcomimus]]."<ref name="tb1997">{{cite book|last=Triebold|first=M.|year=1997|chapter=The Sandy site: Small dinosaurs from the Hell Creek Formation of South Dakota|editor-last=Wolberg|editor-first=D.|editor2-last=Stump|editor2-first=E.|editor3-last=Rosenberg|editor3-first=G.|title=Dinofest International: Proceedings of a Symposium Sponsored by Arizona State University Academy of Natural Science|pages=245–248}}</ref> The birds known from the formation are ''[[Avisaurus]]'',<ref name="weishampel" /> ''[[Brodavis]] baileyi'',<ref name="brodavis">{{Cite journal|last1=Martin|first1=L.D.|last2=Kurochkin|first2=E.N.|last3=Tokaryk|first3=T.T.|date=2012|title=A new evolutionary lineage of diving birds from the Late Cretaceous of North America and Asia|journal=[[Palaeoworld]]|volume=21|pages=59–63|doi=10.1016/j.palwor.2012.02.005}}</ref> and two unnamed [[Hesperornithiform|hesperornithoforms]], possibly ''[[Potamornis]]''.<ref name="pnas" /> Only three [[oviraptorosauria|oviraptorosaurs]] are from the Hell Creek Formation, ''[[Anzu (dinosaur)|Anzu]]'', ''[[Leptorhynchos (dinosaur)|Leptorhynchos]]''<ref name=Anzu /> and third and undescribed specimen, very similar to ''[[Gigantoraptor]]'', from South Dakota. However, only fossilized foot prints were discovered as of 2016.<ref name="http://rmdrc.blogspot.com/2013/12/giant-oviraptor-tracks-from-hell-creek.html">{{cite web|url=http://rmdrc.blogspot.com/2013/12/giant-oviraptor-tracks-from-hell-creek.html|title=Giant Oviraptor Tracks from the Hell Creek|last1=Maltese|first1=A.|website=RMDRC paleo lab|date=17 December 2013|publisher=Blogspot|access-date=17 December 2013}}</ref> The known troodontids from this formation include ''[[Troodon]]'', ''[[Pectinodon]]'', and ''[[Paronychodon]]''. A single species of [[coelurosaur]] is known from similar fossil formations includes ''[[Richardoestesia]]''.
+Evans ''et al.'' found that ''Acheroraptor'' was the only dromaeosaurid from the Hell Creek Formation. Common teeth previously referred to ''[[Dromaeosaurus]]'' and ''[[Saurornitholestes]]'' would then be considered ''Acheroraptor''. Evans ''et al.'' also concluded that there was probably only one dromaeosaurid in the Hell Creek-Lance assemblage.<ref name=Acheroraptor /> In 2015, this view was disproven, with the description of ''[[Dakotaraptor]]'', a far larger second dromaeosaur from the formation.<ref name="DePalmaetal">{{cite journal|last1=DePalma|first1=R.A.|last2=Burnham|first2=D.A.|last3=Martin|first3=L.D.|last4=Larson|first4=P.L.|last5=Bakker|first5=R.T.|date=2015|title=The First Giant Raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation|url=https://kuscholarworks.ku.edu/handle/1808/18764|journal=Paleontological Contributions|issue=14|pages=1–16|doi=10.17161/paleo.1808.18764|s2cid=17099603|doi-access=free}}</ref> Other non-dromaeosaurid theropods from the formation are [[tyrannosauridae|tyrannosaurids]], [[ornithomimidae|ornithomimids]], [[troodontidae|troodontids]],<ref name="weishampel">{{cite book|last1=Weishampel|first1=D.B.|title=The Dinosauria|url=https://archive.org/details/dinosauriandedit00weis|url-access=limited|last2=Dodson|first2=P.|last3=Osmólska|first3=H.|publisher=University of California Press|year=2004|isbn=0520242092|edition=2nd|location=Berkeley, California|pages=[https://archive.org/details/dinosauriandedit00weis/page/n879 861]}}</ref> [[birds]],<ref name="pnas">{{Cite journal|last1=Longrich|first1=N.R.|last2=Tokaryk|first2=T.|last3=Field|first3=D.J.|date=2011|title=Mass extinction of birds at the Cretaceous-Paleogene (K-Pg) boundary|journal=Proceedings of the National Academy of Sciences|volume=108|issue=37|pages=15253–15257|bibcode=2011PNAS..10815253L|doi=10.1073/pnas.1110395108|pmc=3174646|pmid=21914849|doi-access=free}}</ref> and [[caenagnathidae|caenagnathids]].<ref name="Anzu">{{Cite journal|last1=Lamanna|first1=M.C.|last2=Sues|first2=H.D.|last3=Schachner|first3=E.R.|last4=Lyson|first4=T.R.|date=2014|title=A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America|journal=PLOS ONE|volume=9|issue=3|pages=e92022|doi=10.1371/journal.pone.0092022|pmc=3960162|pmid=24647078|bibcode=2014PLoSO...992022L|doi-access=free}}</ref> The tyrannosaurids from the formation are ''[[Nanotyrannus]]'' and ''Tyrannosaurus'', although the former might be a junior synonym of the latter. Among ornithomimids are the genera ''[[Struthiomimus]]'' as well as ''[[Ornithomimus]]'',<ref name="weishampel" /> and "[[Orcomimus]]."<ref name="tb1997">{{cite book|last=Triebold|first=M.|year=1997|chapter=The Sandy site: Small dinosaurs from the Hell Creek Formation of South Dakota|editor-last=Wolberg|editor-first=D.|editor2-last=Stump|editor2-first=E.|editor3-last=Rosenberg|editor3-first=G.|title=Dinofest International: Proceedings of a Symposium Sponsored by Arizona State University Academy of Natural Science|pages=245–248}}</ref> The birds known from the formation are ''[[Avisaurus]]'',<ref name="weishampel" /> ''[[Brodavis]] baileyi'',<ref name="brodavis">{{Cite journal|last1=Martin|first1=L.D.|last2=Kurochkin|first2=E.N.|last3=Tokaryk|first3=T.T.|date=2012|title=A new evolutionary lineage of diving birds from the Late Cretaceous of North America and Asia|journal=[[Palaeoworld]]|volume=21|pages=59–63|doi=10.1016/j.palwor.2012.02.005}}</ref> and two unnamed [[Hesperornithiform|hesperornithoforms]], possibly ''[[Potamornis]]''.<ref name="pnas" /> Only three [[oviraptorosauria|oviraptorosaurs]] are from the Hell Creek Formation, ''[[Anzu (dinosaur)|Anzu]]'', ''[[Leptorhynchos (dinosaur)|Leptorhynchos]]''<ref name=Anzu /> and third and undescribed specimen, very similar to ''[[Gigantoraptor]]'', from South Dakota. However, only fossilized foot prints were discovered as of 2016.<ref name="http://rmdrc.blogspot.com/2013/12/giant-oviraptor-tracks-from-hell-creek.html">{{cite web|url=http://rmdrc.blogspot.com/2013/12/giant-oviraptor-tracks-from-hell-creek.html|title=Giant Oviraptor Tracks from the Hell Creek|last1=Maltese|first1=A.|website=RMDRC paleo lab|date=17 December 2013|publisher=Blogspot|access-date=17 December 2013}}</ref> The known troodontids from this formation include ''[[Troodon]]'', ''[[Pectinodon]]'', and ''[[Paronychodon]]''. A single species of [[coelurosaur]] is known from similar fossil formations includes ''[[Richardoestesia]]''.
-[[File:Acheroraptor NT small.jpg|thumb|Life reconstruction of ''Acheroraptor temertyorum''|alt=|left]]
+[[File:Acheroraptor NT small.jpg|thumb|Life reconstruction of ''A. temertyorum''|alt=|left]]
-[[Ornithischia]]ns are abundant in the Hell Creek Formation. The main groups of ornithischians are [[ankylosauria]]ns, [[ornithopoda|ornithopods]], [[ceratopsia]]ns, and [[pachycephalosauria]]ns. One ankylosaurian and two nodosaurians are known, ''[[Ankylosaurus]]'', ''[[Denversaurus]]'' and possibly ''[[Edmontonia]]''. Multiple genera of ceratopsians are known from the formation, the [[leptoceratopsidae|leptoceratopsid]] ''[[Leptoceratops]]'' and the [[Chasmosaurinae|chasmosaurines]] ''[[Nedoceratops]]'', ''[[Torosaurus]]'', ''Triceratops'',<ref name="weishampel" /> and ''[[Tatankaceratops]]''.<ref name="tatanka">{{cite book|last1=Ott|first1=C.J.|url=https://www.google.com/books/edition/New_Perspectives_on_Horned_Dinosaurs/OWpQW_WhPAsC?hl=en&gbpv=1&dq=New+Perspectives+on+Horned+Dinosaurs:+The+Royal+Tyrrell+Museum+Ceratopsian+Symposium&printsec=frontcover|title=New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium|last2=Larson|first2=P.L.|publisher=Indiana University Press|year=2010|isbn=9780253353580|editor-last=Ryan|editor-first=M.J.|location=Bloomington|pages=656|chapter=A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description|editor2-last=Chinnery-Allgeier|editor2-first=B.J.|editor3-last=Eberth|editor3-first=D.A.}}</ref> Hadrosaurs are common in the Hell Creek Formation, and are known from multiple species of the ornithopod ''[[Thescelosaurus]]'', and the [[hadrosauridae|hadrosaurids]] ''[[Edmontosaurus]]'',<ref name="weishampel" /><ref name="hcfhadro">{{Cite journal|last1=Campione|first1=N.S.E.|last2=Evans|first2=D.C.|date=2011|title=Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America|journal=PLOS ONE|volume=6|issue=9|pages=e25186|doi=10.1371/journal.pone.0025186|pmc=3182183|pmid=21969872|bibcode=2011PLoSO...625186C|doi-access=free}}</ref> and an undescribed genus similar to ''[[Parasaurolophus]]''. Five pachycephalosaurians have been found in the Hell Creek Formation. Among them are the derived [[pachycephalosauridae|pachycephalosaurids]] ''[[Sphaerotholus]]'', ''[[Stygimoloch]]'',<ref name="weishampel" /> ''[[Dracorex]]'',<ref name="bakker">{{cite book|last1=Bakker|first1=R.T.|last2=Sullivan|first2=R.M.|last3=Porter|first3=V.|last4=Larson|first4=P.|last5=Saulsbury|first5=S.J.|year=2006|chapter=''Dracorex hogwartsia'', n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota|editor-last=Lucas|editor-first=S.G.|editor2-last=Sullivan|editor2-first=R.M.|title=Late Cretaceous vertebrates from the Western Interior|series=New Mexico Museum of Natural History and Science Bulletin|volume=35|pages=331–345|chapter-url=http://econtent.unm.edu/cdm/ref/collection/bulletins/id/710}}</ref> ''[[Pachycephalosaurus]]'',<ref name="weishampel" /> and an undescribed specimen from North Dakota.
+[[Ornithischia]]ns are abundant in the Hell Creek Formation. The main groups of ornithischians are [[ankylosauria]]ns, [[ornithopoda|ornithopods]], [[ceratopsia]]ns, and [[pachycephalosauria]]ns. One ankylosaurian and two nodosaurians are known, ''[[Ankylosaurus]]'', ''[[Denversaurus]]'' and possibly ''[[Edmontonia]]''. Multiple genera of ceratopsians are known from the formation, the [[leptoceratopsidae|leptoceratopsid]] ''[[Leptoceratops]]'' and the [[Chasmosaurinae|chasmosaurines]] ''[[Nedoceratops]]'', ''[[Torosaurus]]'', ''Triceratops'',<ref name="weishampel" /> and ''[[Tatankaceratops]]''.<ref name="tatanka">{{cite book|last1=Ott|first1=C.J.|url=https://books.google.com/books?id=OWpQW_WhPAsC&q=New+Perspectives+on+Horned+Dinosaurs:+The+Royal+Tyrrell+Museum+Ceratopsian+Symposium|title=New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium|last2=Larson|first2=P.L.|publisher=Indiana University Press|year=2010|isbn=9780253353580|editor-last=Ryan|editor-first=M.J.|location=Bloomington|pages=656|chapter=A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description|editor2-last=Chinnery-Allgeier|editor2-first=B.J.|editor3-last=Eberth|editor3-first=D.A.}}</ref> Hadrosaurs are common in the Hell Creek Formation, and are known from multiple species of the ornithopod ''[[Thescelosaurus]]'', and the [[hadrosauridae|hadrosaurids]] ''[[Edmontosaurus]]'',<ref name="weishampel" /><ref name="hcfhadro">{{Cite journal|last1=Campione|first1=N.S.E.|last2=Evans|first2=D.C.|date=2011|title=Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America|journal=PLOS ONE|volume=6|issue=9|pages=e25186|doi=10.1371/journal.pone.0025186|pmc=3182183|pmid=21969872|bibcode=2011PLoSO...625186C|doi-access=free}}</ref> and an undescribed genus similar to ''[[Parasaurolophus]]''. Five pachycephalosaurians have been found in the Hell Creek Formation. Among them are the derived [[pachycephalosauridae|pachycephalosaurids]] ''[[Sphaerotholus]]'', ''[[Stygimoloch]]'',<ref name="weishampel" /> ''[[Dracorex]]'',<ref name="bakker">{{cite book|last1=Bakker|first1=R.T.|last2=Sullivan|first2=R.M.|last3=Porter|first3=V.|last4=Larson|first4=P.|last5=Saulsbury|first5=S.J.|year=2006|chapter=''Dracorex hogwartsia'', n. gen., n. sp., a spiked, flat-headed pachycephalosaurid dinosaur from the Upper Cretaceous Hell Creek Formation of South Dakota|editor-last=Lucas|editor-first=S.G.|editor2-last=Sullivan|editor2-first=R.M.|title=Late Cretaceous vertebrates from the Western Interior|series=New Mexico Museum of Natural History and Science Bulletin|volume=35|pages=331–345|chapter-url=http://econtent.unm.edu/cdm/ref/collection/bulletins/id/710}}</ref> ''[[Pachycephalosaurus]]'',<ref name="weishampel" /> and an undescribed specimen from North Dakota.
-Mammals are plentiful in the Hell Creek Formation. Groups represented include [[multituberculata|multituberculates]], [[metatheria]]ns, and [[eutheria]]ns. The multituberculates represented include ''[[Paracimexomys]]'',<ref name=":0">{{Cite book|last1=Kielan-Jaworowska|first1=Z.|title=Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure|last2=Cifelli|first2=R.|last3=Luo|first3=Z-X.|date=2004|publisher=Columbia University Press|isbn=9780231119184|location=New York|oclc=61160163}}</ref> the [[cimolomyidae|cimolomyids]] ''[[Paressonodon]]'',<ref name="mammal">{{Cite journal|last1=Wilson|first1=G.P.|date=2013|title=Mammals across the K/Pg boundary in northeastern Montana, U.S.A.: Dental morphology and body-size patterns reveal extinction selectivity and immigrant-fueled ecospace filling|url=https://www.cambridge.org/core/journals/paleobiology/article/mammals-across-the-kpg-boundary-in-northeastern-montana-usa-dental-morphology-and-bodysize-patterns-reveal-extinction-selectivity-and-immigrantfueled-ecospace-filling/8CBD705DC009C6F64215B602B043011B|journal=Paleobiology|volume=39|issue=3|pages=429–469|doi=10.1666/12041|s2cid=36025237}}</ref> ''[[Meniscoessus]]'', ''[[Essonodon]]'', ''[[Cimolomys]]'', ''[[Cimolodon]]'', and ''[[Cimexomys]]''; and the [[neoplagiaulacidae|neoplagiaulacids]] ''[[Mesodma]]'', and ''[[Neoplagiaulax]]''. The [[alphadontidae|alphadontids]] ''[[Alphadon]]'', ''[[Protalphodon]]'', and ''[[Turgidodon]]'', [[pediomyidae|pediomyids]] ''[[Pediomys]]'',<ref name=":0" /> ''[[Protolambda]]'', and ''[[Leptalestes]]'',<ref name="mammalshcf">{{Cite journal|last1=Archibald|first1=J.D.|last2=Zhang|first2=Y.|last3=Harper|first3=T.|last4=Cifelli|first4=R.L.|date=2011|title=Protungulatum, Confirmed Cretaceous Occurrence of an Otherwise Paleocene Eutherian (Placental?) Mammal|journal=Journal of Mammalian Evolution|volume=18|issue=3|pages=153–161|doi=10.1007/s10914-011-9162-1|s2cid=16724836}}</ref> the [[stagodontidae|stagodontid]] ''[[Didelphodon]]'',<ref name=":0" /> the [[Deltatheridiidae|deltatheridiid]] ''[[Nanocuris]]'', the [[herpetotheridiidae|herpetotheriid]] ''[[Nortedelphys]]'',<ref name="mammal" /> and the [[glasbiidae|glasbiid]] ''[[Glasbius]]'' all represent metatherians of the Hell Creek Formation. A few eutherians are known, being represented by ''[[Alostera]]'',<ref name=":0" /> ''[[Protungulatum]]'',<ref name="mammalshcf" /> the [[cimolestidae|cimolestids]] ''[[Cimolestes]]'' and ''[[Batodon]]'', the [[Gypsonictopsidae|gypsonictopsid]] ''[[Gypsonictops]]'', and the possible [[Nyctitheriidae|nyctitheriid]] ''[[Paranyctoides]]''.<ref name=":0" />
+Mammals are plentiful in the Hell Creek Formation. Groups represented include [[multituberculata|multituberculates]], [[metatheria]]ns, and [[eutheria]]ns. The multituberculates represented include ''[[Paracimexomys]]'',<ref name=":0">{{Cite book|last1=Kielan-Jaworowska|first1=Z.|title=Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure|last2=Cifelli|first2=R.|last3=Luo|first3=Z-X.|date=2004|publisher=Columbia University Press|isbn=9780231119184|location=New York|oclc=61160163}}</ref> the [[cimolomyidae|cimolomyids]] ''[[Paressonodon]]'',<ref name="mammal">{{Cite journal|last1=Wilson|first1=G.P.|date=2013|title=Mammals across the K/Pg boundary in northeastern Montana, U.S.A.: Dental morphology and body-size patterns reveal extinction selectivity and immigrant-fueled ecospace filling|url=https://www.cambridge.org/core/journals/paleobiology/article/mammals-across-the-kpg-boundary-in-northeastern-montana-usa-dental-morphology-and-bodysize-patterns-reveal-extinction-selectivity-and-immigrantfueled-ecospace-filling/8CBD705DC009C6F64215B602B043011B|journal=Paleobiology|volume=39|issue=3|pages=429–469|doi=10.1666/12041|bibcode=2013Pbio...39..429W |s2cid=36025237}}</ref> ''[[Meniscoessus]]'', ''[[Essonodon]]'', ''[[Cimolomys]]'', ''[[Cimolodon]]'', and ''[[Cimexomys]]''; and the [[neoplagiaulacidae|neoplagiaulacids]] ''[[Mesodma]]'', and ''[[Neoplagiaulax]]''. The [[alphadontidae|alphadontids]] ''[[Alphadon]]'', ''[[Protalphodon]]'', and ''[[Turgidodon]]'', [[pediomyidae|pediomyids]] ''[[Pediomys]]'',<ref name=":0" /> ''[[Protolambda]]'', and ''[[Leptalestes]]'',<ref name="mammalshcf">{{Cite journal|last1=Archibald|first1=J.D.|last2=Zhang|first2=Y.|last3=Harper|first3=T.|last4=Cifelli|first4=R.L.|date=2011|title=Protungulatum, Confirmed Cretaceous Occurrence of an Otherwise Paleocene Eutherian (Placental?) Mammal|journal=Journal of Mammalian Evolution|volume=18|issue=3|pages=153–161|doi=10.1007/s10914-011-9162-1|s2cid=16724836}}</ref> the [[stagodontidae|stagodontid]] ''[[Didelphodon]]'',<ref name=":0" /> the [[Deltatheridiidae|deltatheridiid]] ''[[Nanocuris]]'', the [[herpetotheridiidae|herpetotheriid]] ''[[Nortedelphys]]'',<ref name="mammal" /> and the [[glasbiidae|glasbiid]] ''[[Glasbius]]'' all represent metatherians of the Hell Creek Formation. A few eutherians are known, being represented by ''[[Alostera]]'',<ref name=":0" /> ''[[Protungulatum]]'',<ref name="mammalshcf" /> the [[cimolestidae|cimolestids]] ''[[Cimolestes]]'' and ''[[Batodon]]'', the [[Gypsonictopsidae|gypsonictopsid]] ''[[Gypsonictops]]'', and the possible [[Nyctitheriidae|nyctitheriid]] ''[[Paranyctoides]]''.<ref name=":0" />
 == See also ==
@@ Line 98: / Line 97: @@
 {{Reflist}}
-{{Paraves|D.}}
+{{Dromaeosauridae}}
-{{Portal bar|Dinosaurs|Cretaceous}}
+{{Portal bar|Dinosaurs}}
 {{Taxonbar|from=Q15215620}}