Acheroraptor: Difference between revisions
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===Fauna=== |
===Fauna=== |
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Many animals and plants have been found in the Hell Creek Formation,<ref name="weishampel"/> the discovery site of ''Acheroraptor''.<ref name=Acheroraptor/> |
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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/> Other non-dromaeosaurid theropods from the formation are [[tyrannosauridae|tyrannosaurids]],<ref name="weishampel"/> [[ornithomimidae|ornithomimids]],<ref name="weishampel"/> [[troodontidae|troodontids]],<ref name="weishampel">{{cite book|last=Weishampel|first=D.B.|last2=Dodson|first2=Peter|last3=Osmólska|first3=H.|year=2004|title=The Dinosauria (Second ed.)|location=Berkeley|publisher=University of California Press|pages=861|isbn=0-520-24209-2}}</ref> [[birds]],<ref name="pnas">{{cite doi|10.1073/pnas.1110395108}}</ref> and [[caenagnathidae|caenagnathids]].<ref name=Anzu>{{cite doi|10.1371/journal.pone.0092022}}</ref> The tyrannosaurids from the formation are ''[[Nanotyrannus]]'' and ''[[Tyrannosaurus]]'', although the former might be a junior synonym of the later.<ref name="weishampel"/> Among ornithomimids are the genera ''[[Struthiomimus]]'' as well as ''[[Ornithomimus]]'',<ref name="weishampel"/> although an undescribed animal named "[[Orcomimus]]" could be from the formation.<ref name="tb1997">{{cite journal|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|journal=Arizona State University Academy of Natural Science|pages=245–248}}</ref> Troodontids are only represented by ''[[Troodon]]'' and ''[[Paronychodon]]'' in the Hell Creek Formation.<ref name="weishampel"/> The birds known from the formation are ''[[Avisaurus]]'',<ref name="weishampel"/> four species of ''[[Brodavis]]'',<ref name="brodavis">{{cite doi|10.1016/j.palwor.2012.02.005}}</ref> and three unnamed [[Hesperornithiform|hesperornithoforms]].<ref name="pnas"/> Only two [[oviraptorosauria|oviraptorosaurs]] are from the Hell Creek Formation, ''[[Anzu (dinosaur)|Anzu]]'', and ''[[Leptorhynchos (dinosaur)|Leptorhynchos]]''.<ref name=Anzu/> |
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/> Other non-dromaeosaurid theropods from the formation are [[tyrannosauridae|tyrannosaurids]],<ref name="weishampel"/> [[ornithomimidae|ornithomimids]],<ref name="weishampel"/> [[troodontidae|troodontids]],<ref name="weishampel">{{cite book|last=Weishampel|first=D.B.|last2=Dodson|first2=Peter|last3=Osmólska|first3=H.|year=2004|title=The Dinosauria (Second ed.)|location=Berkeley|publisher=University of California Press|pages=861|isbn=0-520-24209-2}}</ref> [[birds]],<ref name="pnas">{{cite doi|10.1073/pnas.1110395108}}</ref> and [[caenagnathidae|caenagnathids]].<ref name=Anzu>{{cite doi|10.1371/journal.pone.0092022}}</ref> The tyrannosaurids from the formation are ''[[Nanotyrannus]]'' and ''[[Tyrannosaurus]]'', although the former might be a junior synonym of the later.<ref name="weishampel"/> Among ornithomimids are the genera ''[[Struthiomimus]]'' as well as ''[[Ornithomimus]]'',<ref name="weishampel"/> although an undescribed animal named "[[Orcomimus]]" could be from the formation.<ref name="tb1997">{{cite journal|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|journal=Arizona State University Academy of Natural Science|pages=245–248}}</ref> Troodontids are only represented by ''[[Troodon]]'' and ''[[Paronychodon]]'' in the Hell Creek Formation.<ref name="weishampel"/> The birds known from the formation are ''[[Avisaurus]]'',<ref name="weishampel"/> four species of ''[[Brodavis]]'',<ref name="brodavis">{{cite doi|10.1016/j.palwor.2012.02.005}}</ref> and three unnamed [[Hesperornithiform|hesperornithoforms]].<ref name="pnas"/> Only two [[oviraptorosauria|oviraptorosaurs]] are from the Hell Creek Formation, ''[[Anzu (dinosaur)|Anzu]]'', and ''[[Leptorhynchos (dinosaur)|Leptorhynchos]]''.<ref name=Anzu/> |
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[[Ornithischia|Ornithischians]] are abundant in the Hell Creek Formation. The main groups of ornithischians are [[ankylosauria|ankylosaurians]], [[ornithopoda|ornithopods]], [[ceratopsia|ceratopsians]], and [[pachycephalosauria|pachycephalosaurians]].<ref name="weishampel"/> Two ankylosaurians are known, ''[[Ankylosaurus]]'' and ''[[Edmontonia]]''.<ref name="weishampel"/> Multiple genera of ceratopsians are known from the formation, the [[leptoceratopsidae|leptoceratopsid]] ''[[Leptoceratops]]'', and the [[ceratopsidae|ceratopsids]] ''[[Torosaurus]]'', ''[[Triceratops]]'',<ref name="weishampel"/> and ''[[Tatankaceratops]]''.<ref name="tatanka">{{cite book|last=Ott|first=C.J.|last=Larson|first=P.L.|year=2010|chapter=A New, Small Ceratopsian Dinosaur from the Latest Cretaceous Hell Creek Formation, Northwest South Dakota, United States: A Preliminary Description|editor-last=Ryan|editor-first=M.J.|editor2-last=Chinnery-Allgeier|editor2-first=B.J.|editor3-last=Eberth|editor3-first=D.A.|title=New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium|location=Bloomington|publisher=Indiana University Press|pages=656}}</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"/> or ''[[Anatosaurus]]'',<ref name="hcfhadro">{{cite doi|10.1371/journal.pone.0025186}}</ref> and possible ''[[Parasaurolophus]]''.<ref name="weishampel"/> Four 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 journal|last=Bakker|first=R.T.|last2=Sullivan|first2=R.M.|last3=Porter|first4=V.|last5=Larson|first5=P.|last6=Saulsbury|first6=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|journal=New Mexico Museum of Natural History and Science Bulletin|volume=35|pages=331–345|url=http://www.childrensmuseum.org/themuseum/dinosphere/draco_rex/dracorex_hogwartsia.pdf}}</ref> and ''[[Pachycephalosaurus]]''.<ref name="weishampel"/> |
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==References== |
==References== |
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Revision as of 14:49, 15 April 2014
| Acheroraptor Temporal range: Late Cretaceous,
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|---|---|
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| Restoration | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | Theropoda |
| Family: | †Dromaeosauridae |
| Genus: | †Acheroraptor Evans et al., 2013 |
| Type species | |
| †Acheroraptor temertyorum Evans et al., 2013
| |
Acheroraptor is an extinct genus of dromaeosaurid theropod dinosaur known from the latest Maastrichtian Hell Creek Formation of Montana, USA. It contains a single species, Acheroraptor temertyorum. A. temertyorum is the geologically youngest known species of dromaeosaurid.
Discovery
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]
Phylogeny
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 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 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]
Paleoecology
Habitat
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.[2]
Fauna
Many animals and plants have been found in the Hell Creek Formation,[3] the discovery site of Acheroraptor.[1]
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] Other non-dromaeosaurid theropods from the formation are tyrannosaurids,[3] ornithomimids,[3] troodontids,[3] birds,[4] and caenagnathids.[5] The tyrannosaurids from the formation are Nanotyrannus and Tyrannosaurus, although the former might be a junior synonym of the later.[3] Among ornithomimids are the genera Struthiomimus as well as Ornithomimus,[3] although an undescribed animal named "Orcomimus" could be from the formation.[6] Troodontids are only represented by Troodon and Paronychodon in the Hell Creek Formation.[3] The birds known from the formation are Avisaurus,[3] four species of Brodavis,[7] and three unnamed hesperornithoforms.[4] Only two oviraptorosaurs are from the Hell Creek Formation, Anzu, and Leptorhynchos.[5]
Ornithischians are abundant in the Hell Creek Formation. The main groups of ornithischians are ankylosaurians, ornithopods, ceratopsians, and pachycephalosaurians.[3] Two ankylosaurians are known, Ankylosaurus and Edmontonia.[3] Multiple genera of ceratopsians are known from the formation, the leptoceratopsid Leptoceratops, and the ceratopsids Torosaurus, Triceratops,[3] and Tatankaceratops.[8] Hadrosaurs are common in the Hell Creek Formation, and are known from multiple species of the ornithopod Thescelosaurus, and the hadrosaurids Edmontosaurus[3] or Anatosaurus,[9] and possible Parasaurolophus.[3] Four pachycephalosaurians have been found in the Hell Creek Formation. Among them are the derived pachycephalosaurids Sphaerotholus, Stygimoloch,[3] Dracorex,[10] and Pachycephalosaurus.[3]
References
- ^ a b c d e f g Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1007/s00114-013-1107-5, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1007/s00114-013-1107-5instead. - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/j.epsl.2011.03.008, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1016/j.epsl.2011.03.008instead. - ^ a b c d e f g h i j k l m n o Weishampel, D.B.; Dodson, Peter; Osmólska, H. (2004). The Dinosauria (Second ed.). Berkeley: University of California Press. p. 861. ISBN 0-520-24209-2.
- ^ a b Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1073/pnas.1110395108, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1073/pnas.1110395108instead. - ^ a b Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1371/journal.pone.0092022, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1371/journal.pone.0092022instead. - ^ Triebold, M. (1997). Wolberg, D.; Stump, E.; Rosenberg, G. (eds.). "Dinofest International: Proceedings of a Symposium". Arizona State University Academy of Natural Science: 245–248.
{{cite journal}}:|chapter=ignored (help) - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/j.palwor.2012.02.005, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1016/j.palwor.2012.02.005instead. - ^ 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.
- ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1371/journal.pone.0025186, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1371/journal.pone.0025186instead. - ^ Bakker, R.T.; Sullivan, R.M.; Porter; Larson, P.; Saulsbury, S.J. (2006). Lucas, S.G.; Sullivan, R.M. (eds.). "Late Cretaceous vertebrates from the Western Interior" (PDF). New Mexico Museum of Natural History and Science Bulletin. 35: 331–345.
{{cite journal}}:|chapter=ignored (help);|first4=missing|last4=(help)
