Where: Guanajuato, Mexico (21.0° N, 101.3° W: paleocoordinates 24.2° N, 90.4° W)
• coordinate based on nearby landmark
When: lower Member (Guanjuato Red Conglomerate Formation), Bridgerian (50.3 - 46.2 Ma)
• bed-level stratigraphic resolution
Environment/lithology: terrestrial; lithology not reported
Size classes: macrofossils, mesofossils
Primary reference: I. Ferrusquia. 1989. A new rodent genus from central Mexico and its bearing on the origin of the Caviomorpha. In C. C. Black, M. R. Dawson (eds.), Los Angeles Museum of History, Science Series 33:91-118 [J. Alroy/J. Alroy/M. Uhen]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 16598: authorized by John Alroy, entered by John Alroy on 18.02.1993, edited by Jonathan Tennant
Creative Commons license: CC BY (attribution)
Taxonomic list
there is a date of 49.3 +/- 1.0 Ma (whole-rock K-Ar: Aranda-Gomez and McDowell 1998) for the lower mbr., but it is hundreds of meters thick and directly overlain by a much younger rhyolite, and it is not clear how the fossil locality relates to the dated horizon
originally regarded as late Eocene or early Oligocene, but new taxa indicate a Bridgerian or Uintan age
| Reptilia | |
Paradipsosaurus mexicanus n. gen. n. sp.
Paradipsosaurus mexicanus n. gen. n. sp. Fries 1955 squamates | |
| Mammalia | |
|
Marfilomys aewoodi Ferrusquia 1989 rodent | |
|
Guanajuatomys hibbardi Black and Stephens 1973 rodent | |
|
? Viverravus sp. Marsh 1872 placental | |
|
Tapiroidea indet. Gill 1872 odd-toed ungulate | |
|
? Plesiosoricidae indet. Winge 1917 placental | |
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