Post Ranch ( of the United States)

Also known as Benson sensu stricto; UA loc. 47-0

Where: Cochise County, Arizona (32.0° N, 110.3° W: paleocoordinates 32.1° N, 109.7° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: St. David Formation, Blancan (4.9 - 1.8 Ma)

• "Sigmodon medius datum" of Johnson et al. 1975

•dated at 3.1 +/- 0.7 Ma (FT on zircon) and in combination with paleomag firmly tied to chron C2An.3n, avg age 3.44 Ma: see Johnson et al. 1975

Environment/lithology: lacustrine

• "either a bog, marsh, pool, or small lake" (Brattstrom 1955)

Reposited in the USNM

Primary reference: C. L. Gazin. 1942. The Late Cenozoic vertebrate faunas from the San Pedro Valley, Ariz. Proceedings of the United States National Museum 92:475-518 [J. Alroy/J. Alroy/L. van den Hoek Ostende]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 19628: authorized by John Alroy, entered by John Alroy on 18.02.1993

Creative Commons license: CC BY (attribution)

Taxonomic list

• "Peromyscus sp." is omitted by Johnson et al. 1975
 Salientia - Bufonidae
Bufo sp.2 Laurenti 1768 toad
 Caudata - Urodela
Ambystoma tigrinum2 Green 1825 tiger salamander
 Testudines - Kinosternoidea
Kinosternon arizonense n. sp.2 Gilmore 1922 Arizona mud turtle
 Squamata -
Squamata indet.3 Oppel 1811 squamates
see also Gilmore 1928
 Rodentia - Cricetidae
"Bensonomys arizonae" = Calomys (Bensonomys) arizonae1, "Sigmodon medius" = Sigmodon minor, Neotoma fossilis, "Baiomys minimus" = Peromyscus minimus, Onychomys bensoni
"Bensonomys arizonae" = Calomys (Bensonomys) arizonae1 Gidley 1922 mouse
"Sigmodon medius" = Sigmodon minor Gidley 1922 cotton rat
Neotoma fossilis Gidley 1922 pack rat
"Baiomys minimus" = Peromyscus minimus Gidley 1922 deer mouse
Onychomys bensoni Gidley 1922 grasshopper mouse
 Rodentia - Sciuridae
"Spermophilus bensoni" = Citellus (Otospermophilus) bensoni1
"Spermophilus bensoni" = Citellus (Otospermophilus) bensoni1 Gidley 1922 ground squirrel
 Rodentia - Geomyidae
Cratogeomys bensoni Gidley 1922 pocket gopher
Nerterogeomys minor Gidley 1922 pocket gopher
 Rodentia - Heteromyidae
Perognathinae indet.1, "? Prodipodomys minor" = Dipodomys minor
Perognathinae indet.1 Coues 1875 rodent
"? Prodipodomys minor" = Dipodomys minor Gidley 1922 kangaroo rat
 Lagomorpha - Leporidae
Leporidae indet. Fischer de Waldheim 1817 rabbit
Hypolagus ringoldensis6 Gustafson 1978 rabbit
from "Benson"; "H. sp."
Aluralagus bensonensis1 Gazin 1942 rabbit
 Perissodactyla - Equidae
Nannippus cf. peninsulatus1 Cope 1885 hipparionine horse
Equus sp.1 Linnaeus 1758 horse
 Carnivora - Mustelidae
? Mustelidae indet. Fischer 1817 mustelid carnivore
 Carnivora - Canidae
cf. Borophagus sp.4 Cope 1892 bone-crushing dog
presumably "Canidae indet."; may include B. diversidens of Wang et al. 1999 from "Three and one-half mi section... near Benson"
 Carnivora - Felidae
Felinae indet.1 Trouessart 1885 cat
 Carnivora - Hyaenidae
Chasmaporthetes ossifragus5 Hay 1921 hyaena
"Benson Area, Cochise County"
 Proboscidea - Gomphotheriidae
Gomphotheriidae indet. Hay 1922 gomphothere
"mastodont"; "cf. Cuvieronius sp." of Johnson et al. 1975
Cuvieronius sp.1 Osborn 1923 gomphothere
 Ungulata - Tayassuidae
Platygonus sp. Leconte 1848 peccary
 Ungulata - Camelidae
Camelops sp.1 Leidy 1854 camel
 Ungulata - Antilocapridae
Antilocapridae indet. Gray 1866 pronghorn
"possibly Texoceros": see also Frick 1937