70-2 EVOLUTION OF THE MIOCENE PROTOLABINE CAMELS
Session: Paleontology, Biogeography/Biostratigraphy & Phylogenetic/Morphological Patterns (Posters)
Poster Booth No.: 172
Presenting Author:
Donald ProtheroAuthors:
Prothero, Donald1, Watmore, Kristin I.2, Welsh, Ed3(1) Geological Sciences, California State Polytechnic University, Pomona, CA, USA; Vertebrate Paleontology, Natural History Museum of Los Angeles County, Los Angeles, CA, USA, (2) Earth Sciences, USC, Los Angeles, CA, USA; Vertebrate Paleontology, Natural History Museum of Los Angeles County, Los Angeles, CA, USA, (3) Badlands National Park, Interior, SD, USA,
Abstract:
The protolabines were a subfamily of North American camelids with distinctively long rostra pinched at the base between canine and P1. They have long been misunderstood, or mistaken for other taxa, and only been recognized as a discrete group in the last 50 years. They are distinctive not only in having a constriction of the rostrum, but also a strong buccinator fossa, lateral expansion of the anterior nares, and shortening of the metapodials. Although Honey and Taylor (1978) described new genera, there has been no complete review of the group since then. We recognize just three genera: Protolabis Cope, 1876; Michenia Frick and Taylor, 1971; and Tanymykter Honey and Taylor, 1978. Tanymykter was an early, extremely primitive protolabine that was long mistaken for Oxydactylus. It contains two species, the late Arikareean T. brachydontus, and the larger early Hemingfordian taxon T. longirostris. Protolabis now contains just four species: the primitive Hemingfordian taxon P. saxeus; the type species from the early Barstovian, P. heterodontus (including P. barstowensis and “P. browni”); the highly derived Clarendonian-Hemphillian taxon P. coartatus; and the Clarendonian-Hemphillian P. yavapaiensis. Finally, the much smaller and more derived genus Michenia is known from several species, including the late Arikareean M. agatensis and M. cameloides (= M. deschutesensis), early Hemingfordian M. exilis, and the late Hemingfordian-Barstovian M. mudhillsensis. Thus, the tribe Protolabidini originated in the late Arikareean, diversified rapidly in the Hemingfordian and reached its maximum diversity in the Barstovian, then declined to just two genera and two species in the Clarendonian and early Hemphillian.
Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025
doi: 10.1130/abs/2025AM-6471
© Copyright 2025 The Geological Society of America (GSA), all rights reserved.
EVOLUTION OF THE MIOCENE PROTOLABINE CAMELS
Category
Discipline > Paleontology, Phylogenetic/Morphological Patterns
Description
Session Format: Poster
Presentation Date: 10/19/2025
Presentation Room: HBGCC, Hall 1
Poster Booth No.: 172
Author Availability: 3:30–5:30 p.m.
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