Rancho El Ocote (Basal): Late/Upper Hemphillian, Mexico
collected by O. Carranza-Castañeda

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Lagomorpha - Leporidae
Notolagus velox Wilson 1937
Miller and Carranza-Castaneda 1998
Mammalia - Perissodactyla - Rhinocerotidae
Teleoceras ocotensis Dalquest and Mooser 1980
Dalquest and Mooser 1980
(1 measurement)
    = Teleoceras fossiger Cope 1878
Carranza-Castaneda 1989
    = Teleoceras hicksi Cook 1927
Prothero 1998
Mammalia - Perissodactyla - Equidae
Nannippus minor (Sellards 1916)
    = Nannippus aztecus Mooser 1968
Alroy 2002
Neohipparion eurystyle (Cope 1893)
includes "N. otomii" in part; "N. monias"
Neohipparion otomii n. sp. Mooser 1959
Mooser 1959
synonym of Neohipparion eurystyle
Neohipparion monias n. sp. Mooser 1963
Mooser 1963
synonym of Neohipparion eurystyle
Dinohippus mexicanus (Lance 1950)
original and current combination Pliohippus (Pliohippus) mexicanus
includes "D. ocotensis"
Protohippus muelleri n. sp. Mooser 1964
Mooser 1964
synonym of Pliohippus (Pliohippus) mexicanus
Hippotigris ocotensis n. sp. Mooser 1958
Mooser 1958
synonym of Pliohippus (Pliohippus) mexicanus
Astrohippus stockii (Lance 1950)
original and current combination Pliohippus (Astrohippus) stockii
includes "A. albidens"
Mammalia - Tayassuidae
Desmathyus brachydontus n. sp. Dalquest and Mooser 1980
Dalquest and Mooser 1980
(3 measurements)
    = Catagonus brachydontus Dalquest and Mooser 1980
Alroy 2002
recombined as Protherohyus brachydontus
see Dalquest and Mooser 1980a; probably includes "Prosthennops sp." of Carranza 1989 and Miller and Carranza 1998a
Mammalia - Camelidae
cf. Alforjas sp. Harrison 1979
see also Montellano 1989: presumably includes "Pliauchenia sp."
Megatylopus cf. matthewi Webb 1965
Dalquest and Mooser 1980
concurs with Montellano 1989 (1 measurement)
Palaeolama guanajuatensis n. sp. Dalquest and Mooser 1980
Dalquest and Mooser 1980
recombined as Hemiauchenia guanajuatensis
Hemiauchenia vera (Matthew 1909)
Miller and Carranza-Castaneda 1998
recombined as Pleiolama vera
Mammalia - Antilocapridae
Hexobelomeryx sp. Furlong 1941
    = Hexobelomeryx cf. fricki Furlong 1941
Miller and Carranza-Castaneda 1998
Mammalia - Carnivora - Felidae
Pseudaelurus ? intrepidus (Leidy 1858)
Carranza-Castaneda and Miller 1996
"Rancho El Ocote" - probably this level because Carranza 1989 lists "P. sp."
Mammalia - Carnivora - Ursidae
Agriotherium schneideri Sellards 1916
Miller and Carranza-Castaneda 1998
recombined as Huracan schneideri
Mammalia - Carnivora - Canidae
Miller and Carranza-Castaneda 1998
recombined as Eucyon ferox
Rancho San Martin, 2 km NE of Rancho Viejo, lower Rancho Viejo beds
cf. Osteoborus cyonoides (Martin 1928)
Dalquest and Mooser 1980
    = Borophagus secundus VanderHoof 1931
Miller and Carranza-Castaneda 1998
"O. sp."; confirmed by Wang et al. 1999 DUPLICATE REF 2596 or 2597
Mammalia - Megalonychidae
Megalonyx sp. Harlan 1825
Dalquest and Mooser 1980
Mammalia - Mylodontidae
Paramylodon sp. Brown 1903
    = Mylodontidae indet. Ameghino 1889
Carranza-Castaneda et al. 2000
status unclear in light of Glossotherium vs. Paramylodon taxonomy problem
Mammalia - Proboscidea - Gomphotheriidae
Rhynchotherium sp. Falconer 1868
Dalquest and Mooser 1980
see common names

Geography
Country:Mexico State/province:Guanajuato
Coordinates: 21.1° North, 100.7° West (view map)
Paleocoordinates:21.4° North, 99.1° West
Basis of coordinate:based on nearby landmark
Altitude:2000 meters
Geographic resolution:outcrop
Time
Period:Neogene
10 m.y. bin:Cenozoic 6
*Period:Tertiary *Epoch:Miocene
*Local age/stage:Late/Upper Hemphillian
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:1
Local order:bottom to top
Stratigraphic resolution:group of beds
Stratigraphy comments: apparently includes the Rhino Layer of Flynn et al. 2005, and therefore also the underlying Proboscidean layer; they report a fission track date of 4.8 +/- 0.2 Ma beneath the Proboscidean layer, and the GMPTS chron C3n.4n/C3n.3r transition falls in between the two layers
from the "lower unit, 2-4 m thick" (Carranza-Castañeda and Walton 1992)
Lithology and environment
Primary lithology:green conglomeratic claystone
Secondary lithology:coarse sandstone
Includes fossils?Y
Includes fossils?Y
Lithology description: Arellano (1951): "Bone-bed about 2m thick, of white to light green or yellowish silty sand with coarser detritus disseminated, or in pockets or lenses" Carranza-Castañeda and Walton 1992: "green swelling clay. Pockets of gravel lag consist of subangular to rounded rhyolite and basalt clasts of 3-6 cm (maximum 10 cm) diameter"; macrofossils at GTO 2b are from this "basal clay" and those at GTO 2c are from a "sand and gravel zone (probably a local channel)"
Environment:fluvial indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Disassociated minor elements:some
Collection methods and comments
Collection excludes:some genera
Collection methods:selective quarrying
Reason for describing collection:general faunal/floral analysis
Collectors:O. Carranza-Castañeda
Collection method comments: collected by "trenching" (Carranza-Castañeda and Walton 1992)
Taxonomic list comments:Rancho El Ocote in general spans several meters and three faunal zones: list of Miller and Carranza 1984 is a composite, and that of Dalquest and Mooser 1980a appears to span the lower two zones
following records are of uncertain provenance: ? Indarctos sp. Dalquest and Mooser 1980a Neohipparion gidleyi MacFadden 1984b: "N. otomii" in part
not clear what "Nannippus hesperides" of Dalquest and Mooser 1980a is, but the holotype is clearly a large form of Nannippus: JA pers. obs. 12.1.93; looks more like a medium-sized Neohipparion, especially the referred lower tooth; JA 9.6.96
Machairodus sp. - not described by Carranza and Miller 1996, and record probably pertains to either Arroyo Tepalcates or Rinconada (see); however, M. cf. coloradensis is implied to be present by Miller and Carranza 1998a
Metadata
Also known as:GTO-2; TMM 41685; Arroyo de la Carreta; Rhino layer
Database number:18737
Authorizer:J. Alroy, J. Marcot Enterer:J. Alroy, J. Marcot, J. Wertheim
Modifier:P. Mannion Research group:vertebrate
Created:1995-03-26 00:00:00 Last modified:2020-08-11 08:55:05
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]
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]
1182 O. Carranza-Castaneda, W. E. Miller, and B. J. Kowallis. 2000. Recent discoveries of South America immigrants in faunas from central Mexico with radiometric dates. Journal of Vertebrate Paleontology 20(3):34A [J. Alroy/J. Alroy/J. Ju]
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]
13235% 32840W. W. Dalquest and O. Mooser. 1980. Late Hemphillian mammals of the Ocote local fauna, Guanajuato, Mexico. Pearce-Sellards Series 32:1-25 [J. Alroy/J. Alroy/J. Alroy]
1324 W. W. Dalquest and O. Mooser. 1980. Arctodus pristinus Leidy in the Pleistocene of Aguascalientes, Mexico. Journal of Mammalogy 61(4):724-725 [J. Alroy/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]
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]
57305 O. Mooser. 1958. Una zebra fosil de la Mesa Central de Mexico. Universidad Nacional Autónoma de México, Instituto de Biología, Anales 28:359-363 [J. Marcot/J. Marcot]
57306 O. Mooser. 1959. Un equido fosil del genero Neohipparion de la Mesa Central de Mexico. Universidad Nacional Autónoma de México, Instituto de Biología, Anales 30:375-388 [J. Marcot/J. Marcot]
57307 O. Mooser. 1963. Neohipparion monias n. sp. equido fosil del Plioceno de la Mesa Central de Mexico. Universidad Nacional Autónoma de México, Instituto de Biología, Anales 34:393-396 [J. Marcot/J. Marcot]
57311 O. Mooser. 1964. Una Nueva Especie De Equido Del Genero Protohippus Del Plioceno Medio De La Mesa Central De Mexico. Universidad Nacional Autónoma de México, Instituto de Biología, Anales 35:157-158 [J. Marcot/J. Marcot]
6218 D. R. Prothero. 1998. Rhinocerotidae. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary mammals of North America 595-605 [J. Alroy/J. Alroy/J. Alroy]
23543 D. R. Ruez, Jr. 2005. Earliest record of Palaeolama (Mammalia, Camelidae) with comments on "Palaeolama" guanajuatensis. Journal of Vertebrate Paleontology 25(3):741-744 [J. Alroy/J. Alroy]