Project 4304: J. N. Biewer, J. Velez-Juarbe, J. F. Parham. 2020. Insights on the Dental Evolution of Walruses Based on New Fossil Specimens from California. Journal of Vertebrate Paleontology. 40 (5):e1833896.
Specimen: Callorhinus ursinus (unvouchered)
View: body

Abstract

Twelve new specimens of fossil walruses are described from four Miocene units in California. The new material represents five taxa: (1) a specimen from the Santa Margarita Formation referred to Imagotaria downsi; (2) a specimen from the Valmonte Diatomite Member of the Monterey Formation referred to cf. Pontolis magnus; (3) six specimens from the Monterey Formation referred to a new species of Pontolis (Pontolis barroni, sp. nov.); (4) one specimen from the Oso Member of the Capistrano Formation referred to a new species of Pontolis (Pontolis kohnoi, sp. nov.); (5) three specimens from the Oso Member referred to a new genus and species (Osodobenus eodon, gen. et sp. nov.). A phylogenetic analysis suggests that both the Dusignathinae and an expanded concept of the genus Pontolis represent monophyletic groups. We provide phylogenetic definitions for clade names of odobenids. Two of the new species are represented by specimens of males, females, and juveniles. Analysis of these specimens shows that the dental anatomy of later diverging basal odobenids is more variable than previously considered. The specific pattern of variation is lineage specific and likely corresponds to the intermediate dental morphology of late Miocene odobenids. Osodobenus eodon, gen. et sp. nov., is the first basal odobenid with tusk-like canines, a longitudinally arched palate, and an enlarged infraorbital foramen. These features are plausibly correlated with benthic suction feeding in the odobenins (Pliocene to Recent) and so Os. eodon may represent a case of convergent evolution of benthic feeding in the late Miocene.


Read the article »

Article DOI: 10.1080/02724634.2020.1833896

Project DOI: 10.7934/P4304, http://dx.doi.org/10.7934/P4304
This project containsMatrices
  • 1 Media
  • 1 Matrix
  • 29 Taxa
  • 1 Specimen
  • 91 Characters
Total size of project's media files: 460.98k

Download Project SDD File
Total scored cells: 2166
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 91
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 239
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:91/0
Currently Viewing:
MorphoBank Project 4304

    This research
    supported by

    Authors' Institutions

    • National Museum of Natural History, Smithsonian Institution

    • California State University - Fullerton

    • Natural History Museum of Los Angeles County

    • Smithsonian Institution



    Members

    member name taxa specimens media chars character
    media
    labels
    cell scorings
    (scored, NPA, "-")
    cell
    medialabels
    rules
    Katherine Walton
    Project Administrator
    291191002166
    (2166, 0, 0)
    000


    Taxonomic Overview for Matrix 'M28837' (29 Taxa)

    taxon unscored
    cells
    scored
    cells
    no cell
    support
    NPA
    cells
    "-" cellscell images labels on
    cell images
    member
    access
    [1] Monachus monachus
    Last Modified in 07/06/22
    1909000001
    [2] † Enaliarctos emlongi
    Last Modified in 07/07/22
    8838300001
    [3] † Pteronarctos goedertae
    Last Modified in 07/07/22
    8838300001
    [4] Callorhinus ursinus
    Last Modified in 07/06/22
    1909000001
    [5] † Desmatophoca oregonensis
    Last Modified in 07/07/22
    7868400001
    [6] † Allodesmus gracilis
    Last Modified in 07/07/22
    0949100001
    [7] Erignathus barbatus
    Last Modified in 07/06/22
    0939100001
    [8] † Prototaria primigenia
    Last Modified in 07/07/22
    47444400001
    [9] † Proneotherium repenningi
    Last Modified in 07/07/22
    9828200001
    [10] † Neotherium mirum
    Last Modified in 07/07/22
    2898900001
    [11] † Kamtschatarctos sinelnikovae
    Last Modified in 07/07/22
    50414100001
    [12] † Pseudotaria muramotoi
    Last Modified in 07/07/22
    54373700001
    [13] † Archaeodobenus akamatsui
    Last Modified in 07/07/22
    20717100001
    [14] † Pelagiarctos spp.
    Last Modified in 07/07/22
    57353400001
    [15] † Nanodobenus arandai
    Last Modified in 07/07/22
    63282800001
    [16] † Titanotaria orangensis
    Last Modified in 07/07/22
    8838300001
    [17] † Imagotaria downsi
    Last Modified in 07/07/22
    3988800001
    [18] † Pontolis barroni sp. nov.
    Last Modified in 07/07/22
    6958500001
    [19] † Pontolis kohnoi sp. nov.
    Last Modified in 07/07/22
    12797900001
    [20] † Cf. pontolis magnus
    Last Modified in 07/07/22
    2978900001
    [21] † Osodobenus eodon gen. et sp. nov.
    Last Modified in 07/07/22
    12847900001
    [22] † Gomphotaria pugnax
    Last Modified in 07/07/22
    13787800001
    [23] † Dusignathus seftoni
    Last Modified in 07/07/22
    14797700001
    [24] † Dusignathus santacruzensis
    Last Modified in 07/07/22
    36565500001
    [25] † Aivukus cedrosensis
    Last Modified in 07/07/22
    30616100001
    [26] † Protodobenus japonicus
    Last Modified in 07/07/22
    27646400001
    [27] † Ontocetus emmonsi
    Last Modified in 07/07/22
    3888800001
    [28] † Valenictus chulavistensis
    Last Modified in 07/07/22
    22696900001
    [29] Odobenus rosmarus
    Last Modified in 07/07/22
    2898900001


    Project views

    type number of views Individual items viewed (where applicable)
    Total project views4651
    Project overview369
    Matrix views270Matrix landing page (248 views); Bieweretal Odobenid Matrix R1 (22 views);
    Media views956Media search (803 views); M845225 (153 views);
    Taxon list1990
    Specimen list565
    Views for media list309
    Bibliography190
    Documents list2




    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project2
    Project downloads1
    Matrix downloads1Bieweretal Odobenid Matrix R1 (1 download);