Late Pleistocene Toxodont Fossil Found in North America (USA)

The First Occurrence of a Toxodont (Mammalia, Notoungulata) in the United States

Authors:

1. Ernest L Lundelius (a,*)
2. Vaugn M Bryant (b)
3. Rolfe Mandel (c)
4. Kenneth J Thies (d)
5. Alston Thomas (b)

Affiliations:

a. Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, U.S.A.

b. Department of Anthropology, Texas A&M University (TAMU 4352), College Station, Texas 77843-4352, U.S.A.

c. Kansas Geological Survey, University of Kansas, Lawrence, Kansas 66047, U.S.A.,

d. 410618 Lynbrook Dr., Houston, Texas 77042, U.S.A.

*. Corresponding Author: erniel@mail.utexas.edu

Abstract:

Toxodonts were a group of large-sized notoungulates of South American origin. They were diverse and widespread in South America in deposits ranging in age from late Oligocene to late Pleistocene. Sparse remains have been found from the Pleistocene of isolated regions of Central America. All of the Central American specimens have been referred to the genus Mixotoxodon (Van Frank, 1950). They were not previously known north of the southern Mexican states of Michoacan and Veracruz, except for an unconfirmed report of an occurrence in Tamaulipas (Arroyo-Cabrales et al., 2010). Here we report the occurrence of a single toxodont tooth, a left upper third molar, from late Pleistocene deposits in Harris County, Texas (30◦N). This is the first record of toxodonts, or any notoungulate, in the United States and extends the geographic range of this group
1600 km north of their previously known localities at Hihuitl ´ an, Michoacan (18◦52 30 N, 103◦24 14 W) and La Estribera, Veracruz (18◦07 01.27 N, 94◦53 15.59W) (Polaco et al., 2004) to latitude 30◦N.