186-5 First reported Mio-Pliocene Mammut matthewi from Louisiana

Session: New Approaches to Old Fossil Collections (Posters)

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Abstract:

A partial cranium with M2-M3 and associated tusks of a mammutid was collected from the Thompson Creek site in West Feliciana Parish, Louisiana. This site is considered to be part of the Pascagoula Formation and mammalian biochronology supports an age of Hemphillian 4 (latest Miocene to earliest Pliocene) for the fauna. Dental morphology supports an identification of Mammut matthewi and wear of the M2 and M3 indicates that the specimen is a mature individual. Two complete upper tusks were recovered and are significant due to their unusually small girth proportional to their length compared to Pleistocene Mammut, and are mostly straight with a slight curvature in two planes. The Thompson Creek specimen represents the first pre-Pleistocene mastodon found in Louisiana and the only known record of M. matthewi from the Gulf Coastal Plain west of peninsular Florida.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9519

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