Pearson Ranch (Bed CS20): Duchesnean, California

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Amphibia - Temnospondyli
Reptilia - Testudines - Testudinidae
Brattstrom 1961
two marginals from "C.I.T. Loc. 150" plus fragments from "U.C. Loc. V5236 (= C.I.T. Loc. 143..."
    = Testudinidae indet. Batsch 1788
Lutugin 1894
Reptilia - Testudines - Trionychidae
Reptilia
Reptilia - Boidae
Boidae indet. Gray 1825
Reptilia - Anguidae
Anguidae indet. Gray 1825
Reptilia - Lacertilia
Mammalia - Rodentia - Simimyidae
Simimys simplex (Wilson 1935)
4 specimens
Lillegraven and Wilson 1977; type, see Wilson 1935a
Mammalia - Rodentia - Cylindrodontidae
6 specimens
Wilson 1940c (1 measurement)
Mammalia - Rodentia
3 specimens
"Griphomys nr. alecer"
Kelly 1990
replaces ID of Wilson 1940b, from at CIT 150
Mammalia - Rodentia - Ischyromyidae
Wilson 1940 2 specimens
Kelly 1990 1 specimen
may be the "larger paramyid" ( of Wilson 1940a
Mammalia - Rodentia - Protoptychidae
Presbymys lophatus n. sp. Wilson 1949
3 specimens
CIT 150, Wilson 1949a (5 measurements)
Mammalia - Primates - Omomyidae
5 specimens
from CIT 150: see Stock 1933f;
Mammalia - Sespedectidae
20 specimens
from CIT 150: see Stock 1935c; see Novacek 1985 (3 measurements)
6 specimens
from CIT 150: see Stock 1935c; Novacek 1976
Mammalia - Creodonta - Hyaenodontidae
2 specimens
from CIT 150: Stock 1933a repeated by Mellett 1977
4 specimens
and type of "Pterodon californicus": Stock 1933a; both from CIT 150; (1+3)
Mammalia - Acreodi
12 specimens
from CIT 150: see Stock 1933b; including additional CIT 150 material of Coombs 1971; NISP
Mammalia - Perissodactyla - Brontotheriidae
16 specimens
16+ (1 measurement)
Alroy 2002
see Stock 1935d, Lucas and Schoch 1989b
Mammalia - Perissodactyla - Hyracodontidae
1 specimen
presumably "Triplopodine or Hyrachyid" from CIT 150 of Stock 1936c
Mammalia - Perissodactyla - Amynodontidae
Stock 1933 6 specimens
from CIT 150: see Stock 1933c, 1939a (1 measurement)
Mammalia - Protoceratidae
Kelly 1990
NISP @3
Mammalia - Agriochoeridae
23 specimens
see Golz 1976; NISP @33
Mammalia - Praetragulidae
45 specimens
from CIT 150: see Stock 1934e; NISP @45
Mammalia - Oromerycidae
11 specimens
NISP @11
20 specimens
see Golz 1976; NISP @20
Mammalia - Didelphimorphia - Didelphidae
see common names

Geography
Country:United States State/province:California County:Ventura
Coordinates: 34.3° North, 119.0° West (view map)
Paleocoordinates:38.9° North, 100.3° West (Wright 2013)
Basis of coordinate:based on political unit
Geographic resolution:small collection
Time
Period: Paleogene Epoch: Eocene
10 m.y. bin: Cenozoic 3
*Period:Tertiary
Key time interval: Duchesnean
Age range of interval: 39.7 - 37 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Sespe
Local section:SimiV Local bed:32
Local order:bottom to top
Stratigraphic resolution:bed
Lithology and environment
Primary lithology: not reported
Environment:terrestrial indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection size:203 specimens
Reason for describing collection:general faunal/floral analysis
Taxonomic list comments:Kelly 1990 places UCMP V-5235, V-5368, LACM 5645 at this level, so some of his records may pertain to these sites
initially reported by Stock 1932b
NISP 203+
new "leptictid" of Stock 1935c (NISP 1) said to be lost and of uncertain affinities within the Insectivora by Novacek 1977

following five NISP values estimated from Golz 1976 p. 18
Metadata
Also known as:CIT 150, 150-E, 150-W, 150-1/2
Database number:16810
Authorizer:J. Alroy, P. Holroyd, J. Marcot Enterer:J. Alroy, J. Marcot, P. Holroyd
Modifier:M. Uhen 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:
1681. D. J. Golz and J. A. Lillegraven. 1977. Summary of known occurrences of terrestrial vertebrates from Eocene strata of southern California. Contributions to Geology, University of Wyoming 15(1):43-65 [J. Alroy/J. Alroy/J. Marcot]

Secondary references:

697 B. H. Brattstrom. 1961. Some new fossil tortoises from western North America with remarks on the zoogeography and paleoecology of tortoises. Journal of Paleontology 35(3):543-560 [J. Alroy/M. Sommers/J. Alroy]
28442 G. Calvano, D. R. Prothero, J. Ludtke and E. B. Lander. 2008. Magnetic stratigraphy of the Eocene to Miocene Sespe and Vaqueros formations, Los Angeles and Orange counties, California. Natural History Museum of Los Angeles County Science Series 41:43-61 [M. Uhen/M. Uhen]
2059 T. S. Kelly. 1990. Biostratigraphy of Uintan and Duchesnean land mammal assemblages from the Middle Member of the Sespe Formation, Simi Valley, California. Contributions in Science, Natural History Museum of Los Angeles County 419:1-42 [J. Alroy/J. Alroy/J. Marcot]
3256 C. Stock. 1933. An amynodont skull from the Sespe deposits, California. Proceedings of the National Academy of Sciences 19(8):762-767 [J. Alroy/J. Alroy/J. Alroy]
3691 R. W. Wilson. 1940. Californian paramyid rodents. Carnegie Institution of Washington Publication 514(5):59-84 [J. Alroy/J. Alroy/J. Alroy]