Project 3931: B. C. Moon. 2019. A new phylogeny of ichthyosaurs (Reptilia: Diapsida). Journal of Systematic Palaeontology. 17 (2):129-155.
Specimen: † Ichthyosaurus breviceps (unvouchered)
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Abstract

The largest phylogenetic analysis of ichthyosaurs to date is presented, with 114 ingroup taxa coded at species level. Completeness of the taxa included varied from > 98% to < 2%; 10 taxa were removed a priori using Concatabominations due to incompleteness and taxonomic uncertainty. The data were analysed using three widely used optimization criteria, maximum parsimony, maximum likelihood and Bayesian inference; while similar, each criterion produced different topologies, support and levels of resolution. Maximum parsimony found a poorly-resolved consensus tree with moderate improvement from a posteriori pruning of unstable taxa; however, general support remained low. Tree resolution was reduced more by taxa that lacked codings from phylogenetically important regions of the tree, rather than by those that simply lacked many codings. Resolution present in the most likely tree is poorly supported; sister relationships cannot be confirmed, although similarities are found to the most parsimonious tree. Bayesian inference found poorly resolved consensus trees. While more resolved, an equal-distribution rate prior is significantly worse than the null gamma-distribution rate prior for morphological data, but suggests rate heterogeneity across ichthyosaur phylogeny. Tree comparisons under each analytical criterion failed to select a single best tree; however, the Bayesian inference tree with gamma-distribution rate prior is selected as the best tree based on recent analyses showing improved accuracy using this criterion. Unequivocally resolved clades include Ichthyopterygia, Ichthyosauria, Shastasauria, Euichthyosauria, Parvipelvia and Neoichthyosauria, but with variation in their taxonomic components. Mixosauridae and Ophthalmosauridae are similarly recovered, but their definitions are modified to stem-based definitions to prevent substantial variation of included taxa. Several genera are not monophyletic: Brachypterygius, Leptonectes, Mixosaurus, Ophthalmosaurus, Paraophthalmosaurus, Phalarodon, Platypterygius, Stenopterygius, Temnodontosaurus and Undorosaurus. Complex and variable relationships suggest the need for new characters and a re-evaluation of the state of ichthyosaur phylogenetics.


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Article DOI: 10.1080/14772019.2017.1394922

Project DOI: 10.7934/P3931, http://dx.doi.org/10.7934/P3931
This project containsMatrices
  • 1 Media
  • 1 Matrix
  • 115 Taxa
  • 1 Specimen
  • 287 Characters
Total size of project's media files: 975.22k

Download Project SDD File
Total scored cells: 16532
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 287
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 619
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:283/4
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MorphoBank Project 3931

    Authors' Institutions

    • University of Bristol



    Members

    member name taxa specimens media chars character
    media
    labels
    cell scorings
    (scored, NPA, "-")
    cell
    medialabels
    rules
    MorphoBank Curator
    Project Administrator
    115112870016532
    (15779, 0, 753)
    000
    Benjamin Moon
    Full membership
    0000000
    (0, 0, 0)
    000


    Taxonomic Overview for Matrix 'M27235' (115 Taxa)

    taxon unscored
    cells
    scored
    cells
    no cell
    support
    NPA
    cells
    "-" cellscell images labels on
    cell images
    member
    access
    [1] † Acamptonectes densus
    Taxon name last Modified on 02/17/21
    16312012004002
    [2] † Aegirosaurus leptospondylus
    Taxon name last Modified on 02/17/21
    92185185010002
    [3] † Arthropterygius chrisorum
    Taxon name last Modified on 02/17/21
    222656500002
    [4] † Athabascasaurus bitumineus
    Taxon name last Modified on 02/17/21
    186959506002
    [5] † Barracudasauroides panxianensis
    Taxon name last Modified on 02/17/21
    8619619605002
    [6] † Besanosaurus leptorhynchus
    Taxon name last Modified on 02/17/21
    10018118106002
    [7] † Brachypterygius extremus
    Taxon name last Modified on 02/17/21
    12016016007002
    [8] † Brachypterygius pseudoscythica
    Taxon name last Modified on 02/17/21
    201808006002
    [9] † Californosaurus perrini
    Taxon name last Modified on 02/17/21
    18410210201002
    [10] † Callawayia neoscapularis
    Taxon name last Modified on 02/17/21
    6022222205002
    [11] † Cartorhynchus lenticarpus
    Taxon name last Modified on 02/17/21
    122145145020002
    [12] † Caypullisaurus bonapartei
    Taxon name last Modified on 02/17/21
    10916916909002
    [13] † Chacaicosaurus cayi
    Taxon name last Modified on 02/17/21
    225555507002
    [14] † Chaohusaurus chaoxianensis
    Taxon name last Modified on 02/17/21
    6721321307002
    [15] † Chaohusaurus geishanensis
    Taxon name last Modified on 02/17/21
    17610610605002
    [16] † Chaohusaurus zhangjiawanensis
    Taxon name last Modified on 02/17/21
    114162162011002
    [17] † Contectopalatus atavus
    Taxon name last Modified on 02/17/21
    58218218011002
    [18] † Cryopterygius kielanae
    Taxon name last Modified on 02/17/21
    205777705002
    [19] † Cryopterygius kristiansenae
    Taxon name last Modified on 02/17/21
    11217117104002
    [20] † Cymbospondylus buchseri
    Taxon name last Modified on 02/17/21
    16411911904002
    [21] † Cymbospondylus nichollsi
    Taxon name last Modified on 02/17/21
    17410810805002
    [22] † Cymbospondylus petrinus
    Taxon name last Modified on 02/17/21
    4922922909002
    [23] † Cymbospondylus piscosus
    Taxon name last Modified on 02/17/21
    2834400002
    [24] † Dearcmhara shawcrossi
    Taxon name last Modified on 02/17/21
    273131301002
    [25] † Eurhinosaurus longirostris
    Taxon name last Modified on 02/17/21
    29244244014002
    [26] † Excalibosaurus costini
    Taxon name last Modified on 02/17/21
    8219719708002
    [27] † Gengasaurus nicosiai
    Taxon name last Modified on 02/17/21
    210757502002
    [28] † Grendelius alekseevi
    Taxon name last Modified on 02/17/21
    14713413406002
    [29] † Grendelius zhuravlevi
    Taxon name last Modified on 02/17/21
    242444401002
    [30] † Grippia longirostris
    Taxon name last Modified on 02/17/21
    5822222207002
    [31] † Guizhouichthyosaurus tangae
    Taxon name last Modified on 02/17/21
    2924924909002
    [32] † Guizhouichthyosaurus wolonggangense
    Taxon name last Modified on 02/17/21
    12315915905002
    [33] † Gulosaurus helmi
    Taxon name last Modified on 02/17/21
    12615815803002
    [34] † Hauffiopteryx typicus
    Taxon name last Modified on 02/17/21
    627227209002
    [35] † Himalayasaurus tibetensis
    Taxon name last Modified on 02/17/21
    275121200002
    [36] † Hudsonelpidia brevirostris
    Taxon name last Modified on 02/17/21
    193909004002
    [37] † Hupehsuchus nanchangensis
    Taxon name last Modified on 02/17/21
    114149149024002
    [38] † Ichthyosaurus acutirostris
    Taxon name last Modified on 02/17/21
    12515915903002
    [39] † Ichthyosaurus anningae
    Taxon name last Modified on 02/17/21
    11816416405002
    [40] † Ichthyosaurus breviceps
    Taxon name last Modified on 02/17/21
    5922122107002
    [41] † Ichthyosaurus communis
    Taxon name last Modified on 02/17/21
    028128106002
    [42] † Ichthyosaurus conybeari
    Taxon name last Modified on 02/17/21
    7121021006002
    [43] † Ichthyosaurus larkini
    Taxon name last Modified on 02/17/21
    7120820808002
    [44] † Ichthyosaurus somersetensis
    Taxon name last Modified on 02/17/21
    4723323307002
    [45] † Isfjordosaurus minor
    Taxon name last Modified on 02/17/21
    274131300002
    [46] † Janusaurus lundi
    Taxon name last Modified on 02/17/21
    128149149010002
    [47] † Keilhauia nui
    Taxon name last Modified on 02/17/21
    216686803002
    [48] † Leninia stellans
    Taxon name last Modified on 02/17/21
    206777704002
    [49] † Leptonectes moorei
    Taxon name last Modified on 02/17/21
    16411811805002
    [50] † Leptonectes solei
    Taxon name last Modified on 02/17/21
    16711911901002
    [51] † Leptonectes tenuirostris
    Taxon name last Modified on 02/17/21
    26250250011002
    [52] † Macgowania janiceps
    Taxon name last Modified on 02/17/21
    17411011003002
    [53] † Maiaspondylus lindoei
    Taxon name last Modified on 02/17/21
    199838305002
    [54] † Malawania anachronus
    Taxon name last Modified on 02/17/21
    221626204002
    [55] † Mikadocephalus gracilirostris
    Taxon name last Modified on 02/17/21
    17511010903002
    [56] † Mixosaurus cornalianus
    Taxon name last Modified on 02/17/21
    2525425408002
    [57] † Mixosaurus kuhnschneyderi
    Taxon name last Modified on 02/17/21
    12615515506002
    [58] † Mixosaurus xindianensis
    Taxon name last Modified on 02/17/21
    9119319303002
    [59] † Mollesaurus periallus
    Taxon name last Modified on 02/17/21
    187999901002
    [60] † Muiscasaurus catheti
    Taxon name last Modified on 02/17/21
    207787802002
    [61] † Nannopterygius enthekiodon
    Taxon name last Modified on 02/17/21
    195919101002
    [62] † Ophthalmosaurus icenicus
    Taxon name last Modified on 02/17/21
    0277277010002
    [63] † Ophthalmosaurus natans
    Taxon name last Modified on 02/17/21
    55221221011002
    [64] † Ophthalmosaurus yasykovi
    Taxon name last Modified on 02/17/21
    15412712706002
    [65] † Palvennia hoybergeti
    Taxon name last Modified on 02/17/21
    17110910907002
    [66] † Paraophthalmosaurus kabanovi
    Taxon name last Modified on 02/17/21
    212707005002
    [67] † Paraophthalmosaurus saveljeviensis
    Taxon name last Modified on 02/17/21
    200838304002
    [68] † Parvinatator wapitiensis
    Taxon name last Modified on 02/17/21
    18510010002002
    [69] † Pervushovisaurus bannovkensis
    Taxon name last Modified on 02/17/21
    261262600002
    [70] † Pervushovisaurus campylodon
    Taxon name last Modified on 02/17/21
    266212100002
    [71] † Pessopteryx nisseri
    Taxon name last Modified on 02/17/21
    215696903002
    [72] † Phalarodon callawayi
    Taxon name last Modified on 02/17/21
    15013213205002
    [73] † Phalarodon fraasi
    Taxon name last Modified on 02/17/21
    10917017008002
    [74] † Phalarodon major
    Taxon name last Modified on 02/17/21
    266191902002
    [75] † Phantomosaurus neubigi
    Taxon name last Modified on 02/17/21
    209767602002
    [76] † Platypterygius americanus
    Taxon name last Modified on 02/17/21
    107167167013002
    [77] † Platypterygius australis
    Taxon name last Modified on 02/17/21
    14255255018002
    [78] † Platypterygius hauthali
    Taxon name last Modified on 02/17/21
    244404003002
    [79] † Platypterygius hercynicus
    Taxon name last Modified on 02/17/21
    87188188012002
    [80] † Platypterygius platydactylus
    Taxon name last Modified on 02/17/21
    16811311306002
    [81] † Platypterygius sachicarum
    Taxon name last Modified on 02/17/21
    216676704002
    [82] † Qianichthyosaurus xingyiensis
    Taxon name last Modified on 02/17/21
    13014814809002
    [83] † Qianichthyosaurus zhoui
    Taxon name last Modified on 02/17/21
    70207207010002
    [84] † Quasianosteosaurus vikinghoegdai
    Taxon name last Modified on 02/17/21
    235505002002
    [85] † Sclerocormus parviceps
    Taxon name last Modified on 02/17/21
    151116116020002
    [86] † Shastasaurus liangae
    Taxon name last Modified on 02/17/21
    62194194031002
    [87] † Shastasaurus pacificus
    Taxon name last Modified on 02/17/21
    98169169020002
    [88] † Shastasaurus sikkaniensis
    Taxon name last Modified on 02/17/21
    1759595017002
    [89] † Shonisaurus popularis
    Taxon name last Modified on 02/17/21
    7020920908002
    [90] † Simbirskiasaurus birjukovi
    Taxon name last Modified on 02/17/21
    231535303002
    [91] † Sisteronia seeleyi
    Taxon name last Modified on 02/17/21
    237474703002
    [92] † Stenopterygius aaleniensis
    Taxon name last Modified on 02/17/21
    11216716708002
    [93] † Stenopterygius quadriscissus
    Taxon name last Modified on 02/17/21
    1626426308002
    [94] † Stenopterygius triscissus
    Taxon name last Modified on 02/17/21
    7270270010002
    [95] † Stenopterygius uniter
    Taxon name last Modified on 02/17/21
    8220020005002
    [96] † Suevoleviathan disinteger
    Taxon name last Modified on 02/17/21
    48226226013002
    [97] † Suevoleviathan integer
    Taxon name last Modified on 02/17/21
    54223223010002
    [98] † Sveltonectes insolitus
    Taxon name last Modified on 02/17/21
    8019919908002
    [99] † Temnodontosaurus azerguensis
    Taxon name last Modified on 02/17/21
    146117117024002
    [100] † Temnodontosaurus crassimanus
    Taxon name last Modified on 02/17/21
    13614614605002
    [101] † Temnodontosaurus eurycephalus
    Taxon name last Modified on 02/17/21
    221656501002
    [102] † Temnodontosaurus nuertingensis
    Taxon name last Modified on 02/17/21
    212747401002
    [103] † Temnodontosaurus platyodon
    Taxon name last Modified on 02/17/21
    7268268012002
    [104] † Temnodontosaurus trigonodon
    Taxon name last Modified on 02/17/21
    12263263012002
    [105] † Thaisaurus chonglakmanii
    Taxon name last Modified on 02/17/21
    207757505002
    [106] † Thalattoarchon saurophagis
    Taxon name last Modified on 02/17/21
    211757501002
    [107] † Tholodus schmidi
    Taxon name last Modified on 02/17/21
    265202002002
    [108] † Toretocnemus californicus
    Taxon name last Modified on 02/17/21
    220636304002
    [109] † Toretocnemus zitteli
    Taxon name last Modified on 02/17/21
    15911911909002
    [110] † Undorosaurus gorodischensis
    Taxon name last Modified on 02/17/21
    16511711705002
    [111] † Undorosaurus trautscholdi
    Taxon name last Modified on 02/17/21
    235494903002
    [112] † Utatsusaurus hataii
    Taxon name last Modified on 02/17/21
    9119419402002
    [113] † Wahlisaurus massarae
    Taxon name last Modified on 02/17/21
    17510910903002
    [114] † Wimanius odontopalatus
    Taxon name last Modified on 02/17/21
    234515102002
    [115] † Xinminosaurus catactes
    Taxon name last Modified on 02/17/21
    18110210204002


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