Ixtapa (Miocene of Mexico)

Where: Chiapas, Mexico (16.8° N, 92.9° W: paleocoordinates 17.2° N, 90.3° W)

• coordinate based on nearby landmark

When: Miocene (23.0 - 5.3 Ma)

Environment/lithology: terrestrial

Primary reference: I. Ferrusquia-Villafranca. 1990. Biostratigraphy of the Mexican Continental Miocene: Part I, Introduction and the Northwestern and Central Faunas. Part II, The Southeastern (Oaxacan) Faunas. Part III, The Southeasternmost (Chiapasan) Fauna and Concluding Remarks On the Discussed Vertebrate Record. Paleontologia Mexicana 56:1-149 [J. Alroy/J. Alroy/J. Marcot]more details

PaleoDB collection 18726: authorized by John Alroy, entered by John Alroy on 18.02.1993, edited by Hina Khan

Creative Commons license: CC BY (attribution)

Taxonomic list

• "Ixtapa" specimens of Gomphotherium are from Rio Salado (see); remaining specimens are from several localities 1.5 to 2.8 km WSW of Ixtapa
K-Ar dates for a tuff above the L.F. appear to be unreliable due to "laboratory handling"; according to Ferrusquia 1996, the fossils are from units 10 and 12 in the type section, and the closest dated horizon is unit 17, more than 300 m above, which has been dated at 12.53 +/- 0.20 Ma (K-Ar, biotite), 15.02 +/- 0.35 Ma (K-Ar, biotite), and 16.02 +/- 0.53 (K-Ar, plagioclase); these dates are indeed highly discrepant and too stratigraphically removed to be relevant
Mammalia
 Perissodactyla - Rhinocerotidae
cf. Teleoceras sp. Hatcher 1894 rhinoceros
 Perissodactyla - Equidae
aff. Hippotherium sp.1 Kaup 1832 hipparionine horse
Actinopteri
 Acanthomorphata -
Percomorphaceae indet.2
Family incertae sedis