Project 984: N. R. Longrich, K. Barnes, S. Clark, L. Millar. 2013. Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae. Bulletin of the Peabody Museum of Natural History. 54 (1):23-49.
Specimen: † Leptorhynchos gaddisi (TMM:45920-1)
View: anteroventral

Abstract

Caenagnathid theropods are a relatively common part of the theropod fauna in the Late Cretaceous of Asia and North America, but have not previously been described from the southernmost United States. Here, we describe caenagnathid fossils from the late Campanian Aguja Formation of West Texas, and revise the systematics of caenagnathids from the Campanian of North America. Caenagnathids from the late Campanian of Canada represent three species in three genera: Caenagnathus collinsi, Chirostenotes pergracilis and Leptorhynchos elegans gen. nov. Leptorhynchos is diagnosed by its small size, its short, deep mandible, and the upturned tip of the beak. A single caenagnathid is known from the late Campanian of Utah, Hagryphus giganteus. Two caenagnathid species occur in the Aguja Formation, ?Chirostenotes sp. and Leptorhynchos gaddisi sp. nov. L. gaddisi differs from L. elegans in that the tip of the beak is narrower and less upturned. Phylogenetic analysis recovers Caenagnathidae and Oviraptoridae as monophyletic sister taxa. Within Caenagnathidae, the North American species seem to form a monophyletic assemblage, the Caenagnathinae, within which Chirostenotes and Caenagnathus form a clade to the exclusion of Leptorhynchos. The discovery of Chirostenotes gaddisi provides more evidence for the existence of a distinct dinosaurian fauna in southern North America during the Campanian. Furthermore, the Aguja fossils show that caenagnathids were widespread and highly diverse in the Late Cretaceous of North America. This diversity was maintained in two ways. First, variation in body size and beak shape suggests that diversity within formations is maintained by niche partitioning, in a way analogous to Darwin's finches. Second, diversity is maintained by high degree of endemism, with different species of caenagnathids occurring in different habitats.


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Article DOI: 10.3374/014.054.0102

Project DOI: 10.7934/P984, http://dx.doi.org/10.7934/P984
This project containsMatrices
  • 5 Media
  • 1 Matrix
  • 28 Taxa
  • 1 Specimen
  • 205 Characters
Total size of project's media files: 909.69k

Download Project SDD File
Total scored cells: 2558
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 205
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 644
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:205/0
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MorphoBank Project 984
  • Creation Date:
    03 July 2013
  • Publication Date:
    20 May 2016
  • Project views: 16699

    Authors' Institutions

    • Yale University



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    Maureen Admin
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    Seth Kaufman
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    Nicholas Longrich
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    Taxonomic Overview for Matrix 'M2208' (28 Taxa)

    taxon unscored
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    NPA
    cells
    "-" cellscell images labels on
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    [1] † Herrerasaurus
    Last Modified in 05/20/16
    1419119100004
    [2] † Velociraptor
    Last Modified in 05/20/16
    420020001004
    [3] † Archaeopteryx lithographica
    Last Modified in 05/20/16
    3317117101004
    [4] † Incisivosaurus gauthieri
    Last Modified in 05/20/16
    9810710700004
    [5] † Caudipteryx zoui
    Last Modified in 05/20/16
    8512012000004
    [6] † Avimimus portentosus
    Last Modified in 05/20/16
    9710810800004
    [7] † Microvenator celer
    Last Modified in 05/20/16
    148565502004
    [8] † Oviraptor
    Last Modified in 05/20/16
    149565600004
    [9] † Rinchenia mongoliensis
    Last Modified in 05/20/16
    4915615600004
    [10] † Citipati osmolskae
    Last Modified in 05/20/16
    8711811800004
    [11] † Zamin khondt
    Last Modified in 05/20/16
    1019519500004
    [12] † Khaan mckennai
    Last Modified in 05/20/16
    6214314300004
    [13] † Conchoraptor
    Last Modified in 05/20/16
    4016516500004
    [14] † Machairasaurus
    Last Modified in 05/20/16
    192131300004
    [15] † Nemegtomaia
    Last Modified in 05/20/16
    5615014900004
    [16] † Heyuannia
    Last Modified in 05/20/16
    139656501004
    [17] † Ingenia
    Last Modified in 05/20/16
    4715815800004
    [18] † Gigantoraptor erlianensis
    Last Modified in 05/20/16
    128777700004
    [19] † Caenagnathasia martinsoni
    Last Modified in 05/20/16
    185202000004
    [20] † Leptorhynchos elegans
    Last Modified in 05/20/16
    175313000004
    [21] † Leptorhynchos gaddisi
    Last Modified in 05/20/16
    186211900004
    [22] † C. pergracilis
    Last Modified in 05/20/16
    122848300004
    [23] † Caenagnathus collinsi
    Last Modified in 05/20/16
    165404000004
    [24] † C. sp. hell creek
    Last Modified in 05/20/16
    191141400004
    [25] † Hagryphus giganteus
    Last Modified in 05/20/16
    194111100004
    [26] † Elmisaurus rarus
    Last Modified in 05/20/16
    188171700004
    [27] † Nomingia
    Last Modified in 05/20/16
    165404000004
    [28] † Epichirostenotes currei
    Last Modified in 05/20/16
    179262600004


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    Media views4173Media search (2368 views); M305410 (358 views); M305413 (351 views); M305414 (389 views); M305415 (354 views); M305416 (353 views);
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