Project 746: T. A. Dececchi, H. C. E. Larsson, D. W. E. Hone. 2012. Yixianosaurus longimanus (Theropoda: Dinosauria) and its bearing on the evolution of Maniraptora and ecology of the Jehol fauna. Vertebrata PalAsiatica. 50 (2):111-139.
Specimen: Yixianosaurus longimanus (IVPP/V:12638)

Abstract

We re-examine the partial skeleton of the enigmatic small feathered theropod Yixianosaurus longimanus from the Lower Yixian Formation, China. A phylogenetic analysis recovers Yixianosaurus as a basal maniraptoran, in a polytomy with Alvarezsaurus, Therizinosauria, Alvarezsauroidea excluding Alvarezsaurus, and a well-resolved clade of derived maniraptorans including Oviraptorsauria and Paraves. The blend in Yixianosaurus of primitive traits, such as a low brachial index and robust digit III, and derived traits, such as a subrectangular coracoid, suggests a more complicated mosaic of forelimb evolution within Maniraptora than previously proposed. The robust forelimb bones and massive, recurved, and pointed manual unguals suggest Yixianosaurus was predatory, although this assessment remains tentative until more complete fossils of this taxon are found. The basal maniraptoran phylogenetic position implies a larger range of forelimb morphologies at this point in coelurosaurian evolution. In many ways, the robust forelimb and hypertrophied recurved unguals are similar to those of Tanycolagreus and Coelurus, and may offer transitional morphologies between these taxa and basal therizinosaurs and oviraptorosaurs. The presence of large, veined, penneacous, contour feathers on Yixianosaurus indicates the origin of these integumentary structures may be deeper in coelurosaur phylogeny than previously reported. Finally, the robust, elongate forelimbs suggest a different ecological role than inferred for other sympatric small theropods, and lend support for niche partitioning within the small non-avian theropods of the Jehol fauna.


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Project DOI: 10.7934/P746, http://dx.doi.org/10.7934/P746
This project containsMatrices
  • 1 Media
  • 1 Matrix
  • 3 Documents
  • 77 Taxa
  • 1 Specimen
  • 348 Characters
Total size of project's media files: 559.3k

Download Project SDD File
Total scored cells: 11191
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 348
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 795
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:348/0
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MorphoBank Project 746

    Authors' Institutions

    • McGill University

    • University College Dublin



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    Maureen Admin
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    Alex Dececchi
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    Taxonomic Overview for Matrix 'M1742' (77 Taxa)

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    [1] Allosaurus
    Last Modified in 12/05/13
    1733133100003
    [2] Sinraptor
    Last Modified in 12/05/13
    7427427400003
    [3] Ingenia
    Last Modified in 12/05/13
    16118718700003
    [4] Citipati
    Last Modified in 12/05/13
    9525325300003
    [5] Oviraptor
    Last Modified in 12/05/13
    265838300003
    [6] Oviraptor2
    Last Modified in 12/05/13
    24810010000003
    [7] Conchoraptor
    Last Modified in 12/05/13
    19115715700003
    [8] Incisivosaurus
    Last Modified in 12/05/13
    23611211200003
    [9] Microvenator
    Last Modified in 12/05/13
    22212612600003
    [10] Chirostenotes
    Last Modified in 12/05/13
    20614214200003
    [11] Dromaeosaurus
    Last Modified in 12/05/13
    24010810800003
    [12] Deinonychus
    Last Modified in 12/05/13
    7827027000003
    [13] Velociraptor
    Last Modified in 12/05/13
    1633233200003
    [14] Utahraptor
    Last Modified in 12/05/13
    318303000003
    [15] Adasaurus
    Last Modified in 12/05/13
    268808000003
    [16] Achillobator
    Last Modified in 12/05/13
    22012812800003
    [17] Tsaagan
    Last Modified in 12/05/13
    21213613600003
    [18] Saurornitholestes
    Last Modified in 12/05/13
    265838300003
    [19] Sinornithosaurus
    Last Modified in 12/05/13
    16418418400003
    [20] Microraptor
    Last Modified in 12/05/13
    17517317300003
    [21] Rahonavis
    Last Modified in 12/05/13
    23411411400003
    [22] Mononykus
    Last Modified in 12/05/13
    19815015000003
    [23] Shuvuuia
    Last Modified in 12/05/13
    12322522500003
    [24] Patagonykus
    Last Modified in 12/05/13
    259898900003
    [25] Alvarezsaurus
    Last Modified in 12/05/13
    292565600003
    [26] Ornitholestes
    Last Modified in 12/05/13
    13621221200003
    [27] Archaeopteryx
    Last Modified in 12/05/13
    8626226200003
    [28] Avimimus
    Last Modified in 12/05/13
    16917917900003
    [29] Caudipteryx
    Last Modified in 12/05/13
    18516316300003
    [30] Confuciusornis
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    16018818800003
    [31] Struthiomimus
    Last Modified in 12/05/13
    5928928900003
    [32] Gallimimus
    Last Modified in 12/05/13
    5129729700003
    [33] Garudimimus
    Last Modified in 12/05/13
    20314514500003
    [34] Pelecanimimus
    Last Modified in 12/05/13
    273757500003
    [35] Harpymimus
    Last Modified in 12/05/13
    22212612600003
    [36] Troodon
    Last Modified in 12/05/13
    18516316300003
    [37] Saurornithoides
    Last Modified in 12/05/13
    23411411400003
    [38] Saurornithodes2
    Last Modified in 12/05/13
    23111711700003
    [39] Byronosaurus
    Last Modified in 12/05/13
    250989800003
    [40] Sinornithoides
    Last Modified in 12/05/13
    18816016000003
    [41] Sinovenator
    Last Modified in 12/05/13
    12222622600003
    [42] Mei long
    Last Modified in 12/05/13
    12722122100003
    [43] EK troodontid
    Last Modified in 12/05/13
    302464600003
    [44] Segnosaurus
    Last Modified in 12/05/13
    19515315300003
    [45] Erlikosaurus
    Last Modified in 12/05/13
    21713113100003
    [46] Alxasaurus
    Last Modified in 12/05/13
    23711111100003
    [47] Tyrannosaurus
    Last Modified in 12/05/13
    3031831800003
    [48] Gorgosaurus
    Last Modified in 12/05/13
    5629229200003
    [49] Shenzhousaurus
    Last Modified in 12/05/13
    21313513500003
    [50] Ornithomimus
    Last Modified in 12/05/13
    6927927900003
    [51] Archaeornithomimus
    Last Modified in 12/05/13
    19315515500003
    [52] Anserimimus
    Last Modified in 12/05/13
    267818100003
    [53] Huaxiagnathus
    Last Modified in 12/05/13
    18816016000003
    [54] Sinosauropteryx
    Last Modified in 12/05/13
    15319519500003
    [55] Compsognathus
    Last Modified in 12/05/13
    19315515500003
    [56] Buitreraptor
    Last Modified in 12/05/13
    18716116100003
    [57] Unenlagia
    Last Modified in 12/05/13
    24010810800003
    [58] Shanag
    Last Modified in 12/05/13
    312363600003
    [59] Mahakala
    Last Modified in 12/05/13
    254949400003
    [60] Falcarius
    Last Modified in 12/05/13
    8726126100003
    [61] Beipiaosaurus
    Last Modified in 12/05/13
    23311511500003
    [62] Neimongosaurus
    Last Modified in 12/05/13
    22112712700003
    [63] Erliansaurus
    Last Modified in 12/05/13
    275737300003
    [64] Suzhousaurus
    Last Modified in 12/05/13
    24710110100003
    [65] Nothronychus
    Last Modified in 12/05/13
    19615215200003
    [66] Nothronychus2
    Last Modified in 12/05/13
    249999900003
    [67] Enigmosaurus
    Last Modified in 12/05/13
    306424200003
    [68] Nanshiungosaurus
    Last Modified in 12/05/13
    301474700003
    [69] ?Nanshiungosaurus?
    Last Modified in 12/05/13
    3399900003
    [70] Therizinosaurus
    Last Modified in 12/05/13
    292565600003
    [71] Hagryphus
    Last Modified in 12/05/13
    331171700003
    [72] Dilong
    Last Modified in 12/05/13
    17717117100003
    [73] Coelurus
    Last Modified in 12/05/13
    23711111100003
    [74] Protarchaeopteryx
    Last Modified in 12/05/13
    296525200003
    [75] Yanornis
    Last Modified in 12/05/13
    287616100003
    [76] Jeholornis
    Last Modified in 12/05/13
    262868600003
    [77] Yixianosaurus longimanus
    Last Modified in 12/05/13
    305434300003


    Project views

    type number of views Individual items viewed (where applicable)
    Total project views44979
    Project overview4257
    Media views6540Media search (5642 views); M109374 (898 views);
    Matrix views2872Matrix landing page (2539 views); Yixianosaurus matrix (333 views);
    Specimen list3270
    Taxon list24613
    Bibliography1295
    Documents list2132




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project360
    Matrix downloads14Yixianosaurus matrix (14 downloads);
    Media downloads7M109374 (7 downloads);
    Project downloads335
    Document downloads4Dececchi et al. 2012 Yixianosaurus matrix (2 downloads); Yixio matrix (1 download); Copyright information for exemplar media (1 download);