Pearson Ranch (Bed CS20): Duchesnean, California

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Amphibia - Temnospondyli
Anura indet. (Fischer von Waldheim 1813)
Mammalia - Sespedectidae
Proterixoides davisi n. sp. Stock 1935
20 specimens
from CIT 150: see Stock 1935c; see Novacek 1985 (3 measurements)
Sespedectes singularis n. sp. Stock 1935
6 specimens
from CIT 150: see Stock 1935c; Novacek 1976
Mammalia - Acreodi
Simidectes merriami n. sp. (Stock 1933)
12 specimens
from CIT 150: see Stock 1933b; including additional CIT 150 material of Coombs 1971; NISP
Mammalia - Creodonta - Hyaenodontidae
Hyaenodon exiguus n. sp. Stock 1933
2 specimens
from CIT 150: Stock 1933a repeated by Mellett 1977
Hyaenodon vetus n. sp. Stock 1933
4 specimens
and type of "Pterodon californicus": Stock 1933a; both from CIT 150; (1+3)
Mammalia - Perissodactyla - Hyracodontidae
Hyracodontidae indet. Cope 1879
1 specimen
presumably "Triplopodine or Hyrachyid" from CIT 150 of Stock 1936c
Mammalia - Perissodactyla - Amynodontidae
Amynodontopsis bodei n. sp. Stock 1933
Stock 1933 6 specimens
from CIT 150: see Stock 1933c, 1939a (1 measurement)
Mammalia - Perissodactyla - Brontotheriidae
Teleodus californicus n. sp. Stock 1935
16 specimens
16+ (1 measurement)
    = Duchesneodus uintensis Peterson 1931
Alroy 2002
see Stock 1935d, Lucas and Schoch 1989b
Mammalia - Protoceratidae
Leptoreodon sp. Wortman 1898
    = Leptoreodon stocki Kelly 1990
Kelly 1990
NISP @3
Mammalia - Agriochoeridae
Protoreodon pacificus n. sp. Golz 1976
23 specimens
see Golz 1976; NISP @33
Mammalia - Praetragulidae
Simimeryx hudsoni n. sp. Stock 1934
45 specimens
from CIT 150: see Stock 1934e; NISP @45
Mammalia - Oromerycidae
Eotylopus sp. Matthew 1910
11 specimens
NISP @11
Protylopus pearsonensis n. sp. Golz 1976
20 specimens
see Golz 1976; NISP @20
Mammalia - Rodentia - Simimyidae
Simimys simplex (Wilson 1935)
4 specimens
Lillegraven and Wilson 1977; type, see Wilson 1935a
Mammalia - Rodentia - Ischyromyidae
Rapamys sp. Wilson 1940
Kelly 1990 1 specimen
may be the "larger paramyid" ( of Wilson 1940a
Microparamys tricus n. sp. (Wilson 1940)
Wilson 1940 2 specimens
Mammalia - Rodentia - Cylindrodontidae
Pareumys milleri Peterson 1919
6 specimens
Wilson 1940c (1 measurement)
Mammalia - Rodentia
Griphomys aff. alecer Wilson 1940
3 specimens
"Griphomys nr. alecer"
    = Griphomys alecer Wilson 1940
Kelly 1990
replaces ID of Wilson 1940b, from at CIT 150
Mammalia - Rodentia - Protoptychidae
Presbymys lophatus n. sp. Wilson 1949
3 specimens
CIT 150, Wilson 1949a (5 measurements)
Mammalia - Primates - Omomyidae
Chumashius balchi n. sp. Stock 1933
5 specimens
from CIT 150: see Stock 1933f;
Mammalia - Didelphimorphia - Didelphidae
? Didelphidae indet. Gray 1821
Reptilia - Anguidae
Anguidae indet. Gray 1825
Reptilia
Boavus affinis Brattstrom 1955
Reptilia - Boidae
Boidae indet. Gray 1825
Reptilia - Lacertilia
Lacertilia indet. Owen 1842
Reptilia - Testudines - Testudinidae
? Testudo sp. Linnaeus 1758
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
Trionychidae indet. Gray 1825
see common names

Geography
Country:United States State/province:California County:Ventura
Coordinates: 34.3° North, 119.0° West (view map)
Paleocoordinates:33.7° North, 107.3° West
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, J. Marcot, P. Holroyd Enterer:J. Alroy, P. Holroyd, J. Marcot
Modifier:M. Uhen Research group:vertebrate
Created:1993-02-18 00:00:00 Last modified:2022-03-07 08:22:02
Access level:the public Released:1993-02-18 00:00:00
Creative Commons license:CC BY
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]