El Camarón (Miocene of Mexico)

Also known as Nejapa

Where: Oaxaca, Mexico (16.6° N, 96.0° W: paleocoordinates 17.1° N, 93.2° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: El Camarón Formation, Barstovian (16.0 - 13.6 Ma)

• formation "is estimated between 200 and 250 m... The fossil mammals occurred in the lower member (usually the lower part), and were collected at several sites [seven shown on map]... from a zone ~30 m thick at the most"; it intertongues with the Yautepec Tuff, dated at 15.0 +/- 0.8 to 16.7+/- 0.71 by K-Ar (Bravo-Cuevas and Ferrusquía-Villafranca 2006)

• member-level stratigraphic resolution

Environment/lithology: terrestrial; poorly lithified, tuffaceous siltstone and poorly lithified, tuffaceous sandstone

• formation is "Friable to moderately indurated tuffaceous siltstone, sandstone and conglomerate; lower part [yielding the fossils] is finer grained and thinly bedded" (Bravo-Cuevas and Ferrusquía-Villafranca 2006)

Size class: macrofossils

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

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 18722: authorized by John Alroy, entered by John Alroy on 18.02.1993, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

• material of "Merychippus" cf. primus and "M." cf. sejunctus of Bravo-Cuevas and Ferrusquía-Villafranca 2006 may derive from this locality or others near the town of Nejapa
Mammalia
 Perissodactyla - Equidae
Merychippus sp. Leidy 1856 horse
"sensu lato"
Cormohipparion aff. quinni2 Woodburne 1996 hipparionine horse
Neohipparion sp.1 Gidley 1903 hipparionine horse
diagnosis seems very clear-cut; JA pers. obs. 10.10.00
 Carnivora - Mustelidae
Plionictis oaxacaensis Ferrusquia-Villafranca 1990 mustelid carnivore
 Carnivora - Canidae
Canidae indet.3 Fischer 1817 canid
 Proboscidea - Gomphotheriidae
? Gomphotherium sp. Burmeister 1837 gomphothere
 Ungulata - Tayassuidae
Tayassuidae indet.3 Palmer 1897 peccary
 Ungulata - Camelidae
Camelidae indet.3 Gray 1821 camel
cf. Protolabis sp.3 Cope 1876 camel
cf. Procamelus sp.3 Leidy 1858 camel
 Ungulata - Antilocapridae
Merycodus sabulonis3 Frick 1937 pronghorn