File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: A monodactyl nonavian dinosaur and the complex evolution of the alvarezsauroid hand

TitleA monodactyl nonavian dinosaur and the complex evolution of the alvarezsauroid hand
Authors
Issue Date2011
PublisherNational Academy of Sciences. The Journal's web site is located at http://www.pnas.org
Citation
Proceedings Of The National Academy Of Sciences Of The United States Of America, 2011, v. 108 n. 6, p. 2338-2342 How to Cite?
AbstractDigital reduction is a striking evolutionary phenomenon that is clearly exemplified in theropod dinosaurs by the functionally didactyl manus of tyrannosaurids, the flight-adapted manus of birds (Aves), and the tridactyl but digit II-dominated manus of alvarezsauroids. The enlargement of manual digit II in alvarezsauroids and the concurrent reduction of the lateral digits have been interpreted as adaptations for digging, although no detailed biomechanical analysis of hand function has so far been carried out for this group. In the derived alvarezsauroid clade Parvicursorinae, the lateral digits are so small as to be presumably vestigial. Here we report a new alvarezsauroid, Linhenykus monodactylus gen. et sp. nov., based on a specimen from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China. Cladistic analysis identifies Linhenykus as the most basal parvicursorine, and digit II of the manus retains a slender morphology and other primitive features. However, Linhenykus is also highly apomorphic in exhibiting the most extreme reduction of the lateral manual digits seen in any alvarezsauroid. Phalanges are retained only on the most medial digit (digit II), making Linhenykus the only known functionally monodactyl nonavian dinosaur. Other parvicursorines are more primitive in retaining a tridactyl manus but more derived in that digit II is highly robust and shows other apomorphic features in both of its phalanges. The unexpected combination of features seen in the hand of Linhenykus points to a complex mosaic pattern of manual evolution in alvarezsauroids, with loss of the presumably vestigial outer digits being decoupled from change in the form of digit II.
Persistent Identifierhttp://hdl.handle.net/10722/154757
ISSN
2015 Impact Factor: 9.423
2015 SCImago Journal Rankings: 6.883
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorXu, Xen_US
dc.contributor.authorSullivan, Cen_US
dc.contributor.authorPittman, Men_US
dc.contributor.authorChoiniere, JNen_US
dc.contributor.authorHone, Den_US
dc.contributor.authorUpchurch, Pen_US
dc.contributor.authorTan, Qen_US
dc.contributor.authorXiao, Den_US
dc.contributor.authorTan, Len_US
dc.contributor.authorHan, Fen_US
dc.date.accessioned2012-08-08T08:30:15Z-
dc.date.available2012-08-08T08:30:15Z-
dc.date.issued2011en_US
dc.identifier.citationProceedings Of The National Academy Of Sciences Of The United States Of America, 2011, v. 108 n. 6, p. 2338-2342en_US
dc.identifier.issn0027-8424en_US
dc.identifier.urihttp://hdl.handle.net/10722/154757-
dc.description.abstractDigital reduction is a striking evolutionary phenomenon that is clearly exemplified in theropod dinosaurs by the functionally didactyl manus of tyrannosaurids, the flight-adapted manus of birds (Aves), and the tridactyl but digit II-dominated manus of alvarezsauroids. The enlargement of manual digit II in alvarezsauroids and the concurrent reduction of the lateral digits have been interpreted as adaptations for digging, although no detailed biomechanical analysis of hand function has so far been carried out for this group. In the derived alvarezsauroid clade Parvicursorinae, the lateral digits are so small as to be presumably vestigial. Here we report a new alvarezsauroid, Linhenykus monodactylus gen. et sp. nov., based on a specimen from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China. Cladistic analysis identifies Linhenykus as the most basal parvicursorine, and digit II of the manus retains a slender morphology and other primitive features. However, Linhenykus is also highly apomorphic in exhibiting the most extreme reduction of the lateral manual digits seen in any alvarezsauroid. Phalanges are retained only on the most medial digit (digit II), making Linhenykus the only known functionally monodactyl nonavian dinosaur. Other parvicursorines are more primitive in retaining a tridactyl manus but more derived in that digit II is highly robust and shows other apomorphic features in both of its phalanges. The unexpected combination of features seen in the hand of Linhenykus points to a complex mosaic pattern of manual evolution in alvarezsauroids, with loss of the presumably vestigial outer digits being decoupled from change in the form of digit II.en_US
dc.languageengen_US
dc.publisherNational Academy of Sciences. The Journal's web site is located at http://www.pnas.orgen_US
dc.relation.ispartofProceedings of the National Academy of Sciences of the United States of Americaen_US
dc.subject.meshAnimalsen_US
dc.subject.meshBiological Evolutionen_US
dc.subject.meshForelimb - Anatomy & Histology - Physiologyen_US
dc.subject.meshFossilsen_US
dc.subject.meshReptiles - Anatomy & Histology - Physiologyen_US
dc.titleA monodactyl nonavian dinosaur and the complex evolution of the alvarezsauroid handen_US
dc.typeArticleen_US
dc.identifier.emailPittman, M:mpittman@hku.hken_US
dc.identifier.authorityPittman, M=rp01622en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1073/pnas.1011052108en_US
dc.identifier.pmid21262806-
dc.identifier.scopuseid_2-s2.0-79952290345en_US
dc.identifier.hkuros214611-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-79952290345&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume108en_US
dc.identifier.issue6en_US
dc.identifier.spage2338en_US
dc.identifier.epage2342en_US
dc.identifier.isiWOS:000287084500033-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridXu, X=35278991100en_US
dc.identifier.scopusauthoridSullivan, C=25627041500en_US
dc.identifier.scopusauthoridPittman, M=35786415100en_US
dc.identifier.scopusauthoridChoiniere, JN=35277982100en_US
dc.identifier.scopusauthoridHone, D=16241713000en_US
dc.identifier.scopusauthoridUpchurch, P=6701733955en_US
dc.identifier.scopusauthoridTan, Q=35786597200en_US
dc.identifier.scopusauthoridXiao, D=41862779900en_US
dc.identifier.scopusauthoridTan, L=36483556100en_US
dc.identifier.scopusauthoridHan, F=25923913300en_US
dc.identifier.citeulike8687265-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats