Rancho Viejo: Blancan, Mexico

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Proboscidea - Gomphotheriidae
Mammalia - Mylodontidae
    = Glossotherium garbanii n. sp. Montellano and Carranza-Castaneda 1981
Montellano-Ballesteros and Carranza-Castaneda 1986
from Gto. 4 in Arroyo El Tanque
    = Paramylodon garbanii Montellano and Carranza-Castaneda 1981
Alroy 2002
Mammalia - Cingulata - Glyptodontidae
Miller and Carranza-Castaneda 1998
Mammalia - Rodentia - Hydrochoeridae
Neochoerus cordobai n. sp. Carranza-Castaneda and Miller 1989
Carranza-Castaneda and Miller 1988
"N. holmesi" of original list
Mammalia - Rodentia - Caviidae
Carranza-Castaneda and Miller 1988
Mammalia - Rodentia - Sciuridae
omitted from Gto. 6 list of Miller and Carranza 1998a
Spermophilus sp. Cuvier 1825
    = Spermophilus matachicensis Wilson 1949
Miller and Carranza-Castaneda 1998
Mammalia - Lagomorpha - Leporidae
see Miller and Carranza 1982
(1 measurement)
Alroy 2002
see Miller and Carranza 1982
    = Aluralagus cf. bensonensis Gazin 1942
White 1991
P. kansasensis apparently listed in error by Miller and Carranza 1998a
White 1988
presumably "Nekrolagus sp." of Miller and Carranza 1998a
Mammalia - Camelidae
Jimenez-Hidalgo and Carranza-Castaneda 2010
Jimenez-Hidalgo and Carranza-Castaneda 2010
Jimenez-Hidalgo and Carranza-Castaneda 2010
Miller and Carranza-Castaneda 1998
Jimenez-Hidalgo and Carranza-Castaneda 2002
Jimenez-Hidalgo and Carranza-Castaneda 2010
Mammalia - Antilocapridae
Miller and Carranza-Castaneda 1998
Capromeryx sp. Matthew 1902
Jimenez-Hidalgo and Carranza-Castaneda 2001
"Rancho Viejo beds, about 12 km northeast of the city of San Miguel de Allende"
Jimenez-Hidalgo et al. 2004
Gto-4, Gto-6, Gto-18, Gto-45
Mammalia - Tayassuidae
Miller and Carranza-Castaneda 1998
Mammalia - Perissodactyla - Equidae
Carranza-Castaneda and Miller 1988
Mammalia - Carnivora - Felidae
Carranza-Castaneda and Miller 2001
Carranza-Castaneda and Miller 1996
Arrastracaballos (GTO-6), 4 km E of Rancho Viejo; "Felidae indet."
Mammalia - Carnivora - Canidae
Miller and Carranza-Castaneda 1998
from Arrastracaballos, see Wang et al. 1999
Mammalia - Carnivora - Mustelidae
Mustelidae indet. Fischer 1817
Mammalia - Carnivora - Ursidae
Ursidae indet. Gray 1825
see common names

Geography
Country:Mexico State/province:Guanajuato
Coordinates: 21.0° North, 100.8° West (view map)
Paleocoordinates:21.8° North, 99.8° West (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:local area
Time
10 m.y. bin: Cenozoic 6
*Period:Tertiary *Epoch:Pliocene
Key time interval: Blancan
Age range of interval: 4.7 - 1.4 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Rancho Viejo Beds
Local section:RViej Local bed:2
Local order:bottom to top
Stratigraphic resolution:member
Stratigraphy comments: dated at 3.6 Ma by Kowallis et al. 1986 using FT on zircon; this is the younger of two modes, the other being at 30.7 Ma
this date is superseded by paleomag and an Ar/Ar date of 3.36 +/- 0.04 Ma reported by Flynn et al. 2005, which show that all of chron C2An.3n and the neighboring reversed chrons are spanned by the lengthy Blancan fossiliferous interval
overlies Coecillo and Arroyo Tepalcates
Lithology and environment
Primary lithology:brown,yellow silty,sandy claystone
Secondary lithology:volcaniclastic ash
Lithology description: "yellow brown sandy and silty clays with some lenses of volcanic ash and sand" (Jimenez-Hidalgo et al. 2004)
Environment:"floodplain"
Geology comments: "interpreted as floodplain deposits" (Jimenez-Hidalgo et al. 2004)
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:field collection
Reason for describing collection:biostratigraphic analysis
Taxonomic list comments:list of Miller and Carranza 1998a is poorly researched
Metadata
Also known as:Arrastracabllos; Gto-4; GTO-5 (Miller Place); GTO-5A; GTO-5B; Gto-6; Gto. 6; GTO-6; GTO-14 (Cuesta Blanca); Gto-18; GTO-31 (Pajaro Grande); GTO-33 (Pork Chop); Gto-45; Tren Plano
Database number:20077
Authorizer:J. Alroy, J. Marcot Enterer:J. Alroy, J. Marcot
Modifier:J. Alroy Research group:vertebrate
Created:1993-02-18 00:00:00 Last modified:2025-02-22 15:12:02
Access level:the public Released:1993-02-18 00:00:00
Creative Commons license:CC0
Reference information

Primary reference:
2594. W. E. Miller and O. Carranza-Castaneda. 1984. Late Cenozoic Mammals from Central Mexico. Journal of Vertebrate Paleontology 4(2):216-236 [J. Alroy/J. Alroy/J. Ju]

Secondary references:

6294 J. Alroy. 2002. Synonymies and reidentifications of North American fossil mammals. [J. Alroy/J. Alroy/M. Kouvari]
1178 O. Carranza-Castaneda and W. E. Miller. 1988. Univ Nat Auton Mexico Inst Geol Revista 7(2) [J. Alroy/J. Alroy]
1179 O. Carranza-Castaneda and W. E. Miller. 1996. Hemphillian and Blancan felids from central Mexico. Journal of Paleontology 70(3):509-518 [J. Alroy/J. Alroy/J. Marcot]
4184 O. Carranza-Castaneda and W. E. Miller. 2001. Machairodus, recorded in the Blancan of Guanajuato, Mexico. Journal of Vertebrate Paleontology 21(3):38A [J. Alroy/R. Whatley/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]
4188 E. Jimenez-Hidalgo and O. Carranza-Castaneda. 2001. The earliest record of the genus Capromeryx (Mammalia: Antilocapridae) in central Mexico. Journal of Vertebrate Paleontology 21(3):65A-66A [J. Alroy/R. Whatley/J. Alroy]
7293 E. Jimenez-Hidalgo and O. Carranza-Castaneda. 2002. First Pliocene record of Hemiauchenia blancoensis (Mammalia, Camelidae) in Mexico. Journal of Vertebrate Paleontology 22(3):71A-72A [J. Alroy/J. Alroy/J. Alroy]
12061 E. Jimenez-Hidalgo, O. Carranza-Castaneda, and M. Montellano-Ballesteros. 2004. A Pliocene record of Capromeryx (Mammalia: Antilocapridae) in Mexico. Journal of Paleontology 78(6):1179-1186 [J. Alroy/J. Alroy/J. Alroy]
51772 E. Jimenez-Hidalgo and O. Carranza-Castaneda. 2010. Blancan Camelids From San Miguel De Allende, Guanajuato, Central Mexico. Journal of Paleontology 84(1):51-65 [J. Marcot/J. Marcot]
2596 W. E. Miller and O. Carranza-Castaneda. 1998. Late Tertiary Canids from Central Mexico. Journal of Paleontology 72(3):546-556 [J. Alroy/J. Alroy/J. Marcot]
26045% 22980M. Montellano-Ballesteros and O. Carranza-Castaneda. 1986. Descripcion de un milodontido del Blancano temprano de la Mesa Central de Mexico. Revista - Instituto de Geologia 6(2):193-203 [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]