Rancho El Ocote (Medial): Late/Upper Hemphillian, Mexico
collected by O. Carranza-Castañeda, B. Slaughter, C. McKinney
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia
- Rodentia
- Sciuridae
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Paenemarmota sp.
Hibbard and Schultz 1948
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includes "P. mexicana" of Dalquest and Mooser 1980a | ||||||||||
Mammalia
- Rodentia
- Cricetidae
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Cricetidae indet.
Fischer von Waldheim 1817
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Carranza-Castañeda and Walton 1992 | |||||||||
section GTO 2a | ||||||||||
Prosigmodon sp.
Jacobs and Lindsay 1981
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(6 measurements) | ||||||||||
= Prosigmodon ferrusquiai n. sp.
Carranza-Castañeda and Walton 1992
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Carranza-Castañeda and Walton 1992 | |||||||||
sections GTO 2a and 2b | ||||||||||
Prosigmodon oroscoi
Jacobs and Lindsay 1981
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Carranza-Castañeda and Walton 1992 | |||||||||
sections GTO 2a and 2b (6 measurements) | ||||||||||
Prosigmodon chihuahuensis
Lindsay and Jacobs 1985
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Carranza-Castañeda and Walton 1992 | |||||||||
section GTO 2b (1 measurement) | ||||||||||
Baiomys kolbi
Hibbard 1952
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Carranza-Castañeda and Walton 1992 | |||||||||
sections GTO 2a and 2b (1 measurement) | ||||||||||
Neotoma (Paraneotoma) sp.
Hibbard 1967
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Carranza-Castañeda and Walton 1992 | |||||||||
possibly new: section GTO 2a | ||||||||||
Neotoma (Paraneotoma) cf. sawrockensis
Hibbard 1967
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Carranza-Castañeda and Walton 1992 | |||||||||
sections GTO 2a and 2b (4 measurements) | ||||||||||
Calomys sp.
(Waterhouse 1837)
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(5 measurements) | ||||||||||
= Calomys (Bensonomys) baskini
Lindsay and Jacobs 1985
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Carranza-Castañeda and Walton 1992 | |||||||||
sections GTO 2a and 2b | ||||||||||
Calomys (Bensonomys) winklerorum n. sp.
Carranza-Castañeda and Walton 1992
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Carranza-Castañeda and Walton 1992 | |||||||||
sections GTO 2a and 2b (4 measurements) | ||||||||||
Calomys (Bensonomys) elachys
(Lindsay and Jacobs 1985)
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Carranza-Castañeda and Walton 1992 | |||||||||
sections GTO 2a and 2b (1 measurement) | ||||||||||
Mammalia
- Lagomorpha
- Leporidae
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Hypolagus sp.
Dice 1917
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= Hypolagus cf. ringoldensis
Gustafson 1978
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White 1988 | |||||||||
said to be similar to H. oregonensis and H. ringoldensis by Miller and Carranza 1982 | ||||||||||
Notolagus sp.
Wilson 1937
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= Notolagus velox
Wilson 1937
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White 1991 | |||||||||
"N. cf. velox" of Miller and Carranza 1982 DUPLICATE REF 3633 or 3634 | ||||||||||
Mammalia
- Perissodactyla
- Equidae
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Dinohippus mexicanus
(Lance 1950)
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original and current combination Pliohippus (Pliohippus) mexicanus | ||||||||||
Astrohippus stockii
(Lance 1950)
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original and current combination Pliohippus (Astrohippus) stockii | ||||||||||
Mammalia
- Tayassuidae
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Platygonus sp.
Leconte 1848
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Mammalia
- Camelidae
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Megatylopus sp.
(Matthew and Cook 1909)
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original and current combination Pliauchenia (Megatylopus) | ||||||||||
Hemiauchenia vera
(Matthew 1909)
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Montellano 1989 | |||||||||
recombined as Pleiolama vera | ||||||||||
probably includes "H. sp."; may also include "Palaeolama guanajuatensis," although this is much smaller | ||||||||||
Mammalia
- Mylodontidae
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cf. Glossotherium sp.
Owen 1840
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possibly includes "Pampatherium" of Carranza et al. 2000 from "4.7 Ma" level | ||||||||||
Mammalia
- Proboscidea
- Gomphotheriidae
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cf. Stegomastodon sp.
Pohlig 1912
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see common names |
Geography
Country: | Mexico | State/province: | Guanajuato |
Coordinates: | 21.2° North, 100.7° West (view map) | ||
Paleocoordinates: | 21.5° North, 99.1° West | ||
Basis of coordinate: | based on nearby landmark | ||
Geographic resolution: | outcrop |
Time
Period: | Neogene | ||
10 m.y. bin: | Cenozoic 6 | ||
*Period: | Tertiary | *Epoch: | Miocene |
Key time interval: | Late/Upper Hemphillian | ||
Age range of interval: | 10.30000 - 4.90000 m.y. ago | ||
* legacy (obsolete) database fields |
Stratigraphy
Formation: | Rancho Viejo Beds | ||||
Local section: | Ocote | Local bed: | 2 | ||
Local order: | bottom to top | ||||
Stratigraphic resolution: | group of beds | ||||
Stratigraphy comments: level dated at 4.6 Ma FT on zircon; according to Kowallis et al. 1986, this is the youngest of three modes, the others being at 11.0 and 24.5 Ma
this date is superseded by an Ar/Ar date of 4.74 +/- 0.14 Ma reported by Flynn et al. 2005 for an ash immediately overlying the fauna unit is "2-3 m thick, lies disconformably on the lower unit" (Carranza-Castañeda and Walton 1992) |
Lithology and environment
Primary lithology: | tuffaceous,gray,white claystone |
Secondary lithology: | "cross stratification" sandstone |
Lithology description: "gray and white volcanic ash and clay. Crossbedded sand occurs in rare, poorly defined lenses" (Carranza-Castañeda and Walton 1992) | |
Environment: | "channel" |
Geology comments: at GTO 2a the unit is "channeled, muddy clay" and at GTO 2c is is "incised by a sand-mud channel" |
Taphonomy
Modes of preservation: | body |
Size of fossils: | macrofossils,mesofossils |
Preservation of anatomical detail: | good |
Abundance in sediment: | abundant |
Disassociated minor elements: | many |
Collection methods and comments
Collection methods: | bulk,sieve |
Reason for describing collection: | general faunal/floral analysis |
Collectors: | O. Carranza-Castañeda, B. Slaughter, C. McKinney |
Collection method comments: microfossils collected by "screenwashing" (Carranza-Castañeda and Walton 1992) |
Metadata
Also known as: | Arroyo de la Carreta; White layer | ||
Database number: | 18738 | ||
Authorizer: | J. Alroy | Enterer: | J. Alroy |
Modifier: | P. Mannion | Research group: | vertebrate |
Created: | 1995-03-26 00:00:00 | Last modified: | 2020-08-11 08:55:21 |
Access level: | the public | Released: | 1995-03-26 00:00:00 |
Creative Commons license: | CC BY |
Reference information
Primary reference:
1175. | O. Carranza-Castaneda. 1989. Rinocerontes de la fauna local Rancho el Ocote, Mioceno Tardio (Hemfiliano tardio) de estado de Guanajuato. Universidad Nacional Autónoma de México, Instituto de Geológia, Revista, Publicación Especial 8(1):88-99 [J. Alroy/J. Alroy/M. Uhen] |
Secondary references:
6294 | J. Alroy. 2002. Synonymies and reidentifications of North American fossil mammals. [J. Alroy/J. Alroy/M. Kouvari] | |
25387 | O. Carranza-Castañeda and A. H. Walton. 1992. Cricetid rodents from the Rancho El Ocote fauna, late Hemphillian (Pliocene), State of Guanajuato. Universidad Nacional Autónoma de México, Instituto de Geologia, Revista 10(1):71-93 [J. Alroy/J. Alroy] | |
23536 | J. J. Flynn, B. J. Kowallis, C. Nuñez, O. Carranza-Castañeda, W. E. Miller, C. C. Swisher, III, and E. Lindsay. 2005. Geochronology of Hemphillian-Blancan aged strata, Guanajuato, Mexico, and implications for the timing of the Great American Biotic Interchange. Journal of Geology 113:287-307 [J. Alroy/J. Alroy/M. Uhen] | |
6255 | M. Montellano. 1989. Pliocene Camelidae of Rancho El Ocote, central Mexico. Journal of Mammalogy 70(2):359-369 [J. Alroy/J. Alroy/J. Alroy] | |
3632 | J. A. White. 1988. The Archaeolaginae (Mammalia, Lagomorpha) of North America, Excluding Archaeolagus and Panolax. Journal of Vertebrate Paleontology 7(4):425-450 [J. Alroy/J. Alroy/J. Ju] | |
3633 | J. A. White. 1991. North American Leporinae (Mammalia: Lagomorpha) from late Miocene (Clarendonian) to latest Pliocene (Blancan). Journal of Vertebrate Paleontology 11(1):67-89 [J. Alroy/J. Alroy/J. Alroy] |