Project 3938: B. M. Wynd, S. J. Nesbitt, M. R. Stocker, A. B. Heckert. 2019. A Detailed description of Rugarhynchos sixmilensis, gen. et comb. nov. (Archosauriformes, Proterochampsia), and cranial convergence in snout elongation across stem and crown archosaurs. Journal of Vertebrate Paleontology. 39 (6):e1748042.
Specimen: † Rugarhynchos sixmilensis (unvouchered)
View: drawing

Abstract

The Triassic Period (252–201.5 Ma) records a great expansion of saurian diversity and disparity, particularly in skull morphology. Stem archosaurs exhibit substantial cranial disparity, especially by taxa either shortening or elongating the skull. This disparity is exemplified in the North American Late Triassic proterochampsians by the ‘short-faced’ Vancleavea and the ‘long-faced’ doswelliids. To critically investigate skull elongation and character evolution in these proterochampsians, we evaluate ‘Doswellia’ sixmilensis, known from much of a skull, cervical centra, and osteoderms from the Bluewater Creek Member of the Chinle Formation of New Mexico. We redescribe the holotype based on extensive repreparation of the holotype material, resulting in the identification of the orbit and clarifying the extent of related bones. As such, the diagnosis of the taxon is substantially modified and a new genus, Rugarhynchos, gen. nov., is erected. Rugarhynchos sixmilensis, gen. et comb. nov., exhibits an elongate snout with characteristics known in stem and crown archosaurs, including a downturned premaxilla and fluted teeth. We included R. sixmilensis in a phylogenetic analysis of archosauromorphs consisting of 677 characters and 109 taxa under both parsimony and Bayesian models. We recover R. sixmilensis as a doswelliid, sister to Doswellia kaltenbachi. Our parsimony and Bayesian models differ in the placement of Doswelliidae, either as sister to or within Proterochampsidae, respectively. We use archosauromorph relationships from the Bayesian model to estimate cranial disparity between stem and crown archosaurs and find a narrow breadth of morphological disparity in the stem. Our results suggest that crown archosaurs evolved disparate crania from a low-disparate archosauriform condition.


Read the article »

Article DOI: 10.1080/02724634.2019.1748042

Project DOI: 10.7934/P3938, http://dx.doi.org/10.7934/P3938
This project containsMatrices
  • 1 Media
  • 1 Matrix
  • 1 Document
  • 119 Taxa
  • 1 Specimen
  • 677 Characters
Total size of project's media files: 253.79k

Download Project SDD File
Total scored cells: 38756
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 677
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 1572
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:573/104
Currently Viewing:
MorphoBank Project 3938
  • Creation Date:
    22 February 2021
  • Publication Date:
    26 October 2021
  • Matrix downloads: 1

    Authors' Institutions

    • Appalachian State University

    • 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
    MorphoBank Curator
    Project Administrator
    119116770038756
    (35293, 0, 3463)
    000


    Taxonomic Overview for Matrix 'M27694' (119 Taxa)

    taxon unscored
    cells
    scored
    cells
    no cell
    support
    NPA
    cells
    "-" cellscell images labels on
    cell images
    member
    access
    [1] † Petrolacosaurus kansensis
    Taxon name last Modified on 10/26/21
    73526508080001
    [2] † Acerosodontosaurus piveteaui
    Taxon name last Modified on 10/26/21
    443188182046001
    [3] † Youngina capensis
    Taxon name last Modified on 10/26/21
    67547500068001
    [4] † Paliguana whitei
    Taxon name last Modified on 10/26/21
    5688886021001
    [5] † Planocephalosaurus robinsonae
    Taxon name last Modified on 10/26/21
    213393381072001
    [6] † Gephyrosaurus bridensis
    Taxon name last Modified on 10/26/21
    186436409059001
    [7] † Cteniogenys sp.
    Taxon name last Modified on 10/26/21
    364276269042001
    [8] † Simoedosaurus lemoinei
    Taxon name last Modified on 10/26/21
    133485480063001
    [9] † Aenigmastropheus parringtoni
    Taxon name last Modified on 10/26/21
    640383600001
    [10] † Protorosaurus speneri
    Taxon name last Modified on 10/26/21
    175452404063001
    [11] † Amotosaurus rotfeldensis
    Taxon name last Modified on 10/26/21
    343292285047001
    [12] † Macrocnemus bassanii
    Taxon name last Modified on 10/26/21
    218400368063001
    [13] † Tanystropheus longobardicus
    Taxon name last Modified on 10/26/21
    74533477085001
    [14] † Jesairosaurus lehmani
    Taxon name last Modified on 10/26/21
    321304287063001
    [15] † Pamelaria dolichotrachela
    Taxon name last Modified on 10/26/21
    143487482052001
    [16] † Azendohsaurus madagaskarensis
    Taxon name last Modified on 10/26/21
    57568558057001
    [17] † Trilophosaurus buettneri
    Taxon name last Modified on 10/26/21
    79527494076001
    [18] † Noteosuchus colletti
    Taxon name last Modified on 10/26/21
    502163151015001
    [19] † Mesosuchus browni
    Taxon name last Modified on 10/26/21
    70554523055001
    [20] † Howesia browni
    Taxon name last Modified on 10/26/21
    302349322032001
    [21] † Eohyosaurus wolvaardti
    Taxon name last Modified on 10/26/21
    525143137014001
    [22] † Rhynchosaurus articeps
    Taxon name last Modified on 10/26/21
    162463449055001
    [23] † Bentonyx sidensis
    Taxon name last Modified on 10/26/21
    426214213038001
    [24] † Mesodapedon kuttyi
    Taxon name last Modified on 10/26/21
    643313103001
    [25] † Ammorhynchus navajoi
    Taxon name last Modified on 10/26/21
    6224140015001
    [26] † Stenaulorhynchus stockleyi
    Taxon name last Modified on 10/26/21
    113511509055001
    [27] † Brasinorhynchus mariantensis
    Taxon name last Modified on 10/26/21
    391254252034001
    [28] † Chanares rhynchosaur
    Taxon name last Modified on 10/26/21
    638403702001
    [29] † Langeronyx brodiei
    Taxon name last Modified on 10/26/21
    529122121027001
    [30] † Fodonyx spenceri
    Taxon name last Modified on 10/26/21
    543121121013001
    [31] † Isalorhynchus genovefae
    Taxon name last Modified on 10/26/21
    185445441049001
    [32] † Eorasaurus olsoni
    Taxon name last Modified on 10/26/21
    652272400001
    [33] † Prolacertoides jimusarensis
    Taxon name last Modified on 10/26/21
    5916563022001
    [34] † Prolacerta broomi
    Taxon name last Modified on 10/26/21
    30604558056001
    [35] † K australiensis combined
    Taxon name last Modified on 10/26/21
    5599893025001
    [36] † Boreopricea funerea
    Taxon name last Modified on 10/26/21
    366280252039001
    [37] † Archosaurus rossicus holotype
    Taxon name last Modified on 10/26/21
    658191800001
    [38] † Proterosuchus fergusi
    Taxon name last Modified on 10/26/21
    147511496032001
    [39] † Proterosuchus goweri
    Taxon name last Modified on 10/26/21
    418249245014001
    [40] † Proterosuchus alexanderi
    Taxon name last Modified on 10/26/21
    191455451034001
    [41] † "Chasmatosaurus" yuani
    Taxon name last Modified on 10/26/21
    154495481041001
    [42] † Tasmaniosaurus triassicus
    Taxon name last Modified on 10/26/21
    57010295012001
    [43] † Vonhuenia fredericki
    Taxon name last Modified on 10/26/21
    657181802001
    [44] † C rossicus combined
    Taxon name last Modified on 10/26/21
    635414002001
    [45] † C magnus combined
    Taxon name last Modified on 10/26/21
    651252501001
    [46] † Chasmatosuchus vjushkovi
    Taxon name last Modified on 10/26/21
    657222000001
    [47] † Koilamasuchus gonzalezdiazi
    Taxon name last Modified on 10/26/21
    647312802001
    [48] † Kalisuchus rewanensis holotype
    Taxon name last Modified on 10/26/21
    6343833010001
    [49] † Fugusuchus hejiapanensis
    Taxon name last Modified on 10/26/21
    463197194019001
    [50] † Sarmatosuchus otschevi
    Taxon name last Modified on 10/26/21
    44623122407001
    [51] † Guchengosuchus shiguaiensis
    Taxon name last Modified on 10/26/21
    482177170025001
    [52] † Cuyosuchus huenei
    Taxon name last Modified on 10/26/21
    49318817806001
    [53] † Garjainia prima
    Taxon name last Modified on 10/26/21
    109537532035001
    [54] † Garjainia madiba combined
    Taxon name last Modified on 10/26/21
    351320304016001
    [55] † Erythrosuchus africanus
    Taxon name last Modified on 10/26/21
    63576565042001
    [56] † Shansisuchus shansisuchus
    Taxon name last Modified on 10/26/21
    165477471040001
    [57] † Shansisuchus kuyeheensis
    Taxon name last Modified on 10/26/21
    5928075010001
    [58] † Chalishevia cothurnata
    Taxon name last Modified on 10/26/21
    5838684010001
    [59] † Youngosuchus sinensis
    Taxon name last Modified on 10/26/21
    354311304019001
    [60] † Uralosaurus combined
    Taxon name last Modified on 10/26/21
    645262606001
    [61] † Vancleavea campi
    Taxon name last Modified on 10/26/21
    209415410056001
    [62] † Asperoris mnyama
    Taxon name last Modified on 10/26/21
    56610189016001
    [63] † Euparkeria capensis
    Taxon name last Modified on 10/26/21
    41622610026001
    [64] † Dorosuchus neoetus
    Taxon name last Modified on 10/26/21
    57610010001001
    [65] † Yarasuchus deccanensis
    Taxon name last Modified on 10/26/21
    48418618309001
    [66] † Dongusuchus efremovi
    Taxon name last Modified on 10/26/21
    646313100001
    [67] † Teleocrater rhadinus
    Taxon name last Modified on 10/26/21
    406255254017001
    [68] † Spondylosoma absconditum
    Taxon name last Modified on 10/26/21
    609666503001
    [69] † Proterochampsa barrionuevoi
    Taxon name last Modified on 10/26/21
    197439431049001
    [70] † Proterochampsa nodosa
    Taxon name last Modified on 10/26/21
    459202196017001
    [71] † Tropidosuchus romeri
    Taxon name last Modified on 10/26/21
    159497487030001
    [72] † Cerritosaurus binsfeldi
    Taxon name last Modified on 10/26/21
    453208203021001
    [73] † Gualosuchus reigi
    Taxon name last Modified on 10/26/21
    197452442036001
    [74] † Chanaresuchus bonapartei
    Taxon name last Modified on 10/26/21
    68577563042001
    [75] † Pseudochampsa ischigualastensis
    Taxon name last Modified on 10/26/21
    277378372028001
    [76] † Rhadinosuchus gracilis
    Taxon name last Modified on 10/26/21
    57010195012001
    [77] † Archeopelta arborensis
    Taxon name last Modified on 10/26/21
    57510110101001
    [78] † Tarjadia ruthae
    Taxon name last Modified on 10/26/21
    229428424024001
    [79] † Erpetosuchus granti
    Taxon name last Modified on 10/26/21
    362293289024001
    [80] † Erpetosuchus sp
    Taxon name last Modified on 10/26/21
    589847909001
    [81] † Dyoplax arenaceus
    Taxon name last Modified on 10/26/21
    628494702001
    [82] † Jaxtasuchus salomoni
    Taxon name last Modified on 10/26/21
    487182175015001
    [83] † Doswellia kaltenbachi
    Taxon name last Modified on 10/26/21
    309327321047001
    [84] † Parasuchus angustifrons
    Taxon name last Modified on 10/26/21
    425223220032001
    [85] † Parasuchus hislopi
    Taxon name last Modified on 10/26/21
    87560554034001
    [86] † Nicrosaurus kapffi
    Taxon name last Modified on 10/26/21
    222422413040001
    [87] † Smilosuchus spp.
    Taxon name last Modified on 10/26/21
    84553543045001
    [88] † Diandongosuchus fuyuanensis
    Taxon name last Modified on 10/26/21
    282377375020001
    [89] † Ornithosuchus woodwardi
    Taxon name last Modified on 10/26/21
    207446439027001
    [90] † Riojasuchus tenuisceps
    Taxon name last Modified on 10/26/21
    94556544033001
    [91] † Venaticosuchus rusconii
    Taxon name last Modified on 10/26/21
    510152150017001
    [92] † Nundasuchus songeaensis
    Taxon name last Modified on 10/26/21
    43523523309001
    [93] † Turfanosuchus dabanensis
    Taxon name last Modified on 10/26/21
    209449442024001
    [94] † Gracilisuchus stipanicicorum
    Taxon name last Modified on 10/26/21
    136519507034001
    [95] † Yonghesuchus sangbiensis
    Taxon name last Modified on 10/26/21
    496166163018001
    [96] † Parringtonia gracilis
    Taxon name last Modified on 10/26/21
    5918176010001
    [97] † Aetosauroides scagliai
    Taxon name last Modified on 10/26/21
    261406391024001
    [98] † Aetosaurus ferratus
    Taxon name last Modified on 10/26/21
    157496491029001
    [99] † Stagonolepis robertsoni
    Taxon name last Modified on 10/26/21
    53594593031001
    [100] † Ticinosuchus ferox
    Taxon name last Modified on 10/26/21
    404262257016001
    [101] † Qianosuchus mixtus
    Taxon name last Modified on 10/26/21
    255397395027001
    [102] † Arizonasaurus babbitti
    Taxon name last Modified on 10/26/21
    304344339034001
    [103] † Lotosaurus adentus
    Taxon name last Modified on 10/26/21
    257368362058001
    [104] † Xilousuchus sapingensis
    Taxon name last Modified on 10/26/21
    480181180016001
    [105] † Luperosuchus fractus
    Taxon name last Modified on 10/26/21
    56711010802001
    [106] † Decuriasuchus quartacolonia
    Taxon name last Modified on 10/26/21
    307346342028001
    [107] † Batrachotomus kupferzellensis
    Taxon name last Modified on 10/26/21
    123529520030001
    [108] † Prestosuchus chiniquensis
    Taxon name last Modified on 10/26/21
    67585580030001
    [109] † Scleromochlus taylori
    Taxon name last Modified on 10/26/21
    510150139028001
    [110] † Dimorphodon macronyx
    Taxon name last Modified on 10/26/21
    316311306055001
    [111] † Lagerpeton chanarensis
    Taxon name last Modified on 10/26/21
    520141137018001
    [112] † Marasuchus lilloensis
    Taxon name last Modified on 10/26/21
    335318312030001
    [113] † Asilisaurus kongwe
    Taxon name last Modified on 10/26/21
    447215213017001
    [114] † Lewisuchus admixtus
    Taxon name last Modified on 10/26/21
    383277269023001
    [115] † Silesaurus opolensis
    Taxon name last Modified on 10/26/21
    123514504049001
    [116] † Heterodontosaurus tucki
    Taxon name last Modified on 10/26/21
    69535529075001
    [117] † Herrerasaurus ischigualastensis
    Taxon name last Modified on 10/26/21
    63574562052001
    [118] † Rugarhynchos sixmilensis
    Taxon name last Modified on 10/26/21
    488146143046001
    [119] † Litorusuchus somnii
    Taxon name last Modified on 10/26/21
    273384378026001


    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project34
    Project downloads33
    Matrix downloads1Data matrix taken from Supplemental Material (1 download);