26-7 Evolution of the Miocene Protolabine Camels

Session: Interdisciplinary Paleontology: New approaches to solving complex paleontological problems (Posters)

Poster Booth No.: 35

Presenting Author:

Stephanie Lukowski

Authors:

Lukowski, Stephanie M¹, Prothero, Donald R², Welsh, Ed³, Watmore, Kristin I⁴, Forcellati, Meghan R⁵

(1) New Mexico Museum of Natural History & Science, Albuquerque, NM, USA, (2) Department of Geological Sciences, California State Polytechnic University, Pomona,, CA, USA; Natural History Museum of Los Angeles County, Los Angeles, CA, USA, (3) Badlands National Park, Interior, SD, USA, (4) Department of Geological Sciences, University of Southern California, Los Angeles, CA, USA, (5) Department of Herpetology, Richard Gilder Graduate School, American Museum of Natural History, New York, NY, USA,

Abstract:

The protolabines were a subfamily of North American camelids, most of which had 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 the new genus Tanymykter, 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-diverging protolabine that was long mistaken for Oxydactylus. It contains two species, the late Arikareean T. brachyodontus, 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); 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 Programs. Vol. 58, No. 4, 2026

doi: 10.1130/abs/2026RM-14099

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