Project 2527: M. Stocker, S. Nesbitt, K. Criswell, W. Parker, L. Witmer, T. Rowe, R. Ridgely, M. Brown. 2016. A Dome-Headed Stem Archosaur Exemplifies Convergence among Dinosaurs and Their Distant Relatives. Current Biology. 26 (19):2674-2680. (In Press)
Specimen: † Triopticus primus (:TMM 31100-1030)

Abstract

Similarities in body plan evolution, such as wings in pterosaurs, birds, and bats or limblessness in snakes and amphisbaenians, can be recognized as classical examples of convergence among animals [ 1–3 ]. We introduce a new Triassic stem archosaur that is unexpectedly and remarkably convergent with the “dome-headed” pachycephalosaur dinosaurs that lived over 100 million years later. Surprisingly, numerous additional taxa in the same assemblage (the Otis Chalk assemblage from the Dockum Group of Texas) demonstrate the early acquisition of morphological novelties that were later convergently evolved by post-Triassic dinosaurs. As one of the most successful clades of terrestrial vertebrates, dinosaurs came to occupy an extensive morphospace throughout their diversification in the Mesozoic Era [ 4, 5 ], but their distant relatives were first to evolve many of those “dinosaurian” body plans in the Triassic Period [ 6–8 ]. Our analysis of convergence between archosauromorphs from the Triassic Period and post-Triassic archosaurs demonstrates the early and extensive exploration of morphospace captured in a single Late Triassic assemblage, and we hypothesize that many of the “novel” morphotypes interpreted to occur among archosaurs later in the Mesozoic already were in place during the initial Triassic archosauromorph, largely non-dinosaurian, radiation and only later convergently evolved in diverse dinosaurian lineages.


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Article DOI: 10.1016/j.cub.2016.07.066

Project DOI: 10.7934/P2527, http://dx.doi.org/10.7934/P2527
This project containsMatrices
  • 1 Media
  • 1 Matrix
  • 32 Taxa
  • 1 Specimen
  • 247 Characters
Total size of project's media files: 207.72k

Download Project SDD File
Total scored cells: 5589
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 247
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 515
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:247/0
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MorphoBank Project 2527

    Authors' Institutions

    • Petrified Forest National Park, Navajo County

    • Ohio University

    • University of Chicago

    • University of Texas at Austin

    • Virginia Tech (Virginia Polytechnic Institute and State University)



    Members

    member name taxa specimens media chars character
    media
    labels
    cell scorings
    (scored, NPA, "-")
    cell
    medialabels
    rules
    Sterling Nesbitt
    Project Administrator
    3201247005589
    (5287, 0, 302)
    000
    Michelle Stocker
    Full membership
    0000000
    (0, 0, 0)
    000


    Taxonomic Overview for Matrix 'M24245' (32 Taxa)

    taxon unscored
    cells
    scored
    cells
    no cell
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    NPA
    cells
    "-" cellscell images labels on
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    [1] † Petrolacosaurus kansasensis
    Last Modified in 09/22/16
    13218218016002
    [2] Uromastyx sp.
    Last Modified in 09/20/16
    11208208028002
    [3] † Azendohsaurus madagaskarensis
    Last Modified in 09/22/16
    623323209002
    [4] † Azendohsaurus laaroussi
    Last Modified in 09/22/16
    216292902002
    [5] † Trilophosaurus buettneri
    Last Modified in 09/22/16
    8223223016002
    [6] † Trilophosaurus jacobsi
    Last Modified in 09/22/16
    11512712705002
    [7] † Pamelaria dolichotrachela
    Last Modified in 09/22/16
    10513713705002
    [8] † Spinosuchus caseanus
    Last Modified in 09/22/16
    217282802002
    [9] † Prolacerta broomi
    Last Modified in 09/22/16
    1422822607002
    [10] † Teraterpeton hrynewichorum
    Last Modified in 09/22/16
    13011311304002
    [11] † Protorosaurus speneri
    Last Modified in 09/22/16
    62175175010002
    [12] † "Chasmatosaurus" yuani
    Last Modified in 09/22/16
    7516716705002
    [13] † Proterosuchus
    Last Modified in 09/22/16
    2022222205002
    [14] † Proterosuchus alexanderi
    Last Modified in 09/22/16
    6218418401002
    [15] † Youngina capensis
    Last Modified in 09/22/16
    34201201012002
    [16] † Gephyrosaurus bridensis
    Last Modified in 09/22/16
    52181181014002
    [17] † Mesosuchus browni
    Last Modified in 09/22/16
    1822222108002
    [18] † Rhynchosaurus articeps
    Last Modified in 09/22/16
    37193193017002
    [19] † Teyumbaita sulcognathus
    Last Modified in 09/22/16
    82148148017002
    [20] † Langobardisaurus pandolfii
    Last Modified in 09/22/16
    13910710701002
    [21] † Tanystropheus longobardicus
    Last Modified in 09/22/16
    2421721607002
    [22] † Tanytrachelos ahynis
    Last Modified in 09/22/16
    9215015005002
    [23] † Macrocnemus basanii
    Last Modified in 09/22/16
    5518718705002
    [24] † Amotosaurus rotfeldensis
    Last Modified in 09/22/16
    175696903002
    [25] † Erythrosuchus africanus
    Last Modified in 09/22/16
    3620520506002
    [26] Shinisaurus crocodilurus
    Last Modified in 09/20/16
    7220220020002
    [27] † Chanaresuchus bonapartei
    Last Modified in 09/22/16
    204424201002
    [28] † Euparkeria capensis
    Last Modified in 09/22/16
    4219819807002
    [29] † Batrachotomus kupferzellensis
    Last Modified in 09/22/16
    30205204013002
    [30] † Coelophysis bauri
    Last Modified in 09/22/16
    12210209026002
    [31] † Plateosaurus engelhardti
    Last Modified in 09/22/16
    8215214025002
    [32] † Triopticus primus
    Last Modified in 09/22/16
    222252500002


    Project views

    type number of views Individual items viewed (where applicable)
    Total project views24125
    Project overview2617
    Media views4372Media search (3758 views); M431891 (614 views);
    Matrix views1893Matrix landing page (1716 views); Triopticus relationships (177 views);
    Taxon list12227
    Bibliography910
    Specimen list2102
    Documents list4




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project269
    Project downloads249
    Matrix downloads18Triopticus relationships (18 downloads);
    Media downloads2M431891 (2 downloads);