Project 3708: M. Iijima, Y. Kobayashi. 2019. Mosaic nature in the skeleton of East Asian crocodylians fills the morphological gap between “Tomistominae” and Gavialinae. Cladistics. 35 (6):623-632.
Specimen: † Toyotamaphimeia machikanensis (MOUF:00001)
View: skeleton reconstruction

Abstract

Crocodylian systematics has long been confounded by conflicting hypotheses of higher level relationships—although molecular data sets strongly supported the sister‐taxon relationship of Tomistoma and Gavialis, morphological data sets placed Gavialis as sister to all other living taxa. One of the perceived difficulties in interpreting morphological character evolution on the molecular tree is the extensive character reversal occurring in Gavialinae, the mechanism of which has yet to be explained. Here, we provide evidence of gavialine‐specific atavistic characters from East Asian “tomistomines” Penghusuchus pani and Toyotamaphimeia machikanensis. These taxa exhibit a mosaic assembly of “tomistomine” and gavialine features, which fill the gap between the two longirostrine groups. Although the parsimony analysis of morphological data (69 taxa, 254 characters) still supports the previous morphological hypothesis, the alternative tree that was forced to fit the molecular hypothesis was insignificantly (5/954 steps; 0.52%) longer than the unconstrained tree, suggesting that morphological evolution can also be interpreted on the molecular tree. Although the problem of stratigraphic gaps remains, future studies may be directed to resolving the interrelationships within Gavialoidea, a large longirostrine group of crocodylians, in the molecular tree context.


Read the article »

Article DOI: 10.1111/cla.12372

Project DOI: 10.7934/P3708, http://dx.doi.org/10.7934/P3708
This project contains
  • 1 Media
  • 2 Documents
  • 2 Taxa
  • 1 Specimen
Total size of project's media files: 732.75k

Download Project SDD File
Currently Viewing:
MorphoBank Project 3708

    Authors' Institutions

    • Hokkaido University

    • Hefei University of Technology



    Members

    member name taxa specimens media
    MorphoBank Curator
    Project Administrator
    Last logged in 04/23/20
    211
    Masaya Iijima
    Full membership
    Last logged in 04/22/20
    000


    Project has no matrices defined.



    Project views

    type number of views Individual items viewed (where applicable)
    Total project views110
    Project overview27
    Documents list18
    Bibliography3
    Media views27Media search (24 views); M687529 (3 views);
    Views for media list6
    Specimen list14
    Taxon list15




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project3
    Project downloads3