Project 5143: R. W. Boessenecker, A. W. Poust, S. J. Boessenecker, M. Churchill. 2023. Tusked walruses (Carnivora: Odobenidae) from the Miocene-Pliocene Purisima Formation of Santa Cruz, California (U.S.A.): a new species of the toothless walrus Valenictus and the oldest records of Odobeninae and Odobenini. Journal of Vertebrate Paleontology. 43 (3):null.
Abstract
Currently limited to cold climates near the Arctic circle, living walruses are the sole survivors of a previously much more diverse clade that occupied coastal waters throughout the northern hemisphere during the Mio–Pliocene. Though pinniped faunas have the highest diversity of walruses in the Miocene, the Purisima Formation of California records a moderately diverse assemblage of four walrus species. We report new specimens of tusked walruses (Odobeninae) including the oldest known members of Odobeninae, and Odobenini, and fossils of the specialized toothless odobenine walrus Valenictus Mitchell, Citation1961. Among these is the new species Valenictus sheperdi sp. nov., represented by a complete skull and referred post-crania from lower Pliocene strata within the Purisima Formation (5.33–4.89 Ma). Additionally, we report a geochronologically younger skull of Valenictus chulavistensis Deméré, 1994 from further up section (4.89–3.59 Ma). Expanded phylogenetic analysis recovers Odobeninae including Ontocetus Leidy, Citation1859 as the earliest diverging lineage in the Odobenini, and places a monophyletic Valenictus as the sister taxon to Pliopedia, Kellogg, Citation1921 which is included in a phylogeny for the first time; Odobenus is sister to the Valenictus + Pliopedia clade. Discovery of an isolated metacarpal near the base of the formation provides the oldest known well-dated evidence of odobenines. A diverse assemblage of molluskivores characterized the Neogene eastern North Pacific and their extinction around the Pliocene–Pleistocene boundary coincided with tectonically driven paleogeographic changes on the Pacific coast. The loss of temperate walruses may have provided opportunities for both new molluskivores and the otariid and phocid pinnipeds that make up present North Pacific pinniped communities.Read the article »
Article DOI: 10.1080/02724634.2023.2296567
Project DOI: 10.7934/P5143, http://dx.doi.org/10.7934/P5143
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 3580 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 143 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 398 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:71/72 |
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MorphoBank Project 5143
MorphoBank Project 5143
- Creation Date:
22 March 2024 - Publication Date:
22 March 2024 - Project views: 613
Authors' Institutions
- University of California Berkeley
- University of Nebraska-Lincoln
- University of Wisconsin
- San Diego Natural History Museum
- Charleston Center for Paleontology
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
MorphoBank Curator Project Administrator | 35 | 2 | 2 | 143 | 0 | 0 | 3580 (3580, 0, 0) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29728' (35 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Enaliarctos emlongi Last Modified in 03/22/24 | 9 | 134 | 134 | 0 | 0 | 0 | 0 | 1 |
[2] † Pteronarctos goedertae Last Modified in 03/22/24 | 9 | 135 | 134 | 0 | 0 | 0 | 0 | 1 |
[3] Callorhinus ursinus Last Modified in 03/22/24 | 1 | 144 | 142 | 0 | 0 | 0 | 0 | 1 |
[4] † Desmatophoca oregonensis Last Modified in 03/22/24 | 8 | 136 | 135 | 0 | 0 | 0 | 0 | 1 |
[5] † Allodesmus kernensis Last Modified in 03/22/24 | 4 | 140 | 138 | 0 | 0 | 0 | 0 | 1 |
[6] † Erignathus barbatus Last Modified in 03/22/24 | 4 | 139 | 139 | 0 | 0 | 0 | 0 | 1 |
[7] Monachus monachus Last Modified in 03/22/24 | 2 | 141 | 141 | 0 | 0 | 0 | 0 | 1 |
[8] † Prototaria primigena Last Modified in 03/22/24 | 51 | 92 | 92 | 0 | 0 | 0 | 0 | 1 |
[9] † Prototaria planicephala Last Modified in 03/22/24 | 54 | 89 | 89 | 0 | 0 | 0 | 0 | 1 |
[10] † Proneotherium repenningi Last Modified in 03/22/24 | 11 | 132 | 132 | 0 | 0 | 0 | 0 | 1 |
[11] † Neotherium mirum Last Modified in 03/22/24 | 6 | 137 | 136 | 0 | 0 | 0 | 0 | 1 |
[12] † Kamtschatarctos sinelnikovae Last Modified in 03/22/24 | 108 | 35 | 35 | 0 | 0 | 0 | 0 | 1 |
[13] † Pseudotaria muramotoi Last Modified in 03/22/24 | 81 | 63 | 60 | 0 | 0 | 0 | 0 | 1 |
[14] † Archaeodobenus akamatsui Last Modified in 03/22/24 | 42 | 101 | 101 | 0 | 0 | 0 | 0 | 1 |
[15] † Imagotaria downsi Last Modified in 03/22/24 | 5 | 139 | 137 | 0 | 0 | 0 | 0 | 1 |
[16] † Pelagiarctos Last Modified in 03/22/24 | 112 | 31 | 31 | 0 | 0 | 0 | 0 | 1 |
[17] † Nanodobenus arandai Last Modified in 03/22/24 | 120 | 23 | 23 | 0 | 0 | 0 | 0 | 1 |
[18] † Pontolis magnus Last Modified in 03/22/24 | 4 | 141 | 138 | 0 | 0 | 0 | 0 | 1 |
[19] † Pontolis barroni Last Modified in 03/22/24 | 12 | 131 | 131 | 0 | 0 | 0 | 0 | 1 |
[20] † Pontolis kohnoi Last Modified in 03/22/24 | 17 | 126 | 126 | 0 | 0 | 0 | 0 | 1 |
[21] † Titanotaria orangensis Last Modified in 03/22/24 | 12 | 131 | 131 | 0 | 0 | 0 | 0 | 1 |
[22] † Osodobenus eodon Last Modified in 03/22/24 | 15 | 128 | 128 | 0 | 0 | 0 | 0 | 1 |
[23] † Dusignathus santacruzensis Last Modified in 03/22/24 | 65 | 78 | 78 | 0 | 0 | 0 | 0 | 1 |
[24] † Dusignathus seftoni Last Modified in 03/22/24 | 15 | 128 | 126 | 0 | 0 | 0 | 0 | 1 |
[25] † Gomphotaria pugnax Last Modified in 03/22/24 | 28 | 116 | 112 | 0 | 0 | 0 | 0 | 1 |
[26] † Aivukus cedrosensis Last Modified in 03/22/24 | 41 | 103 | 100 | 0 | 0 | 0 | 0 | 1 |
[27] † Protodobenus japonicus Last Modified in 03/22/24 | 45 | 99 | 97 | 0 | 0 | 0 | 0 | 1 |
[28] † Ontocetus sp. Last Modified in 03/22/24 | 65 | 78 | 77 | 0 | 0 | 0 | 0 | 1 |
[29] † Ontocetus emmonsi Last Modified in 03/22/24 | 21 | 122 | 113 | 0 | 0 | 0 | 0 | 1 |
[30] Odobenus rosmarus Last Modified in 03/22/24 | 6 | 137 | 137 | 0 | 0 | 0 | 0 | 1 |
[31] † Pliopedia pacifica Last Modified in 03/22/24 | 128 | 15 | 15 | 0 | 0 | 0 | 0 | 1 |
[32] † Valenictus imperialensis Last Modified in 03/22/24 | 139 | 4 | 4 | 0 | 0 | 0 | 0 | 1 |
[33] † Valenictus sheperdi Last Modified in 03/22/24 | 68 | 75 | 75 | 0 | 0 | 0 | 0 | 1 |
[34] † Valenictus chulavistensis Last Modified in 03/22/24 | 39 | 105 | 103 | 0 | 0 | 0 | 0 | 1 |
[35] † Valenictus ucmp 137426 Last Modified in 03/22/24 | 91 | 52 | 51 | 0 | 0 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 613 | |
Matrix views | 27 | Matrix landing page (25 views); Matrix (2 views); |
Project overview | 49 | |
Bibliography | 23 | |
Views for media list | 36 | |
Specimen list | 78 | |
Media views | 138 | Media search (106 views); M902683 (16 views); M902684 (16 views); |
Taxon list | 262 |