Spring Canyon: Duchesnean - Early/Lower Chadronian, California

List of taxa
Where & when
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Primates - Microsyopidae
Uintasoricinae indet. Szalay 1969
Mammalia - Rodentia
Diplolophus sp. Troxell 1923
said to be new
    = Nonomyinae indet. Martin 1980
Walsh 2010
said to be new: from SDSNH 4042
Nonomys sp. Emry and Dawson 1973
said to be new (33 measurements)
    = Nonomys gutzleri n. sp. Walsh 2010
Walsh 2010
type is from SDSNH Locality 4041; also present at 4042
Mammalia - Rodentia - Eomyidae
cf. Paradjidaumo sp. Burke 1934
Protadjidaumo sp. Burke 1934
cf. Metanoiamys sp. Chiment and Korth 1996
Mammalia - Rodentia
cf. Griphomys sp. Wilson 1940
said to be new
Mammalia - Rodentia - Heliscomyidae
Heliscomys sp. Cope 1873
Mammalia - Rodentia - Ischyromyidae
Ischyromys sp. Leidy 1856
Mammalia - Lipotyphla - Geolabididae
Centetodon cf. magnus (Clark 1936)
Mammalia - Perissodactyla - Equidae
Mesohippus sp. Marsh 1875
Mammalia - Carnivora - Mustelidae
Mustelidae indet. Fischer 1817
Mammalia - Ungulata - Camelidae
Camelidae indet. Gray 1821
Mammalia - Ungulata - Agriochoeridae
? Agriochoeridae indet. Leidy 1869
Mammalia - Ungulata - Hypertragulidae
cf. Hypertragulus sp. Cope 1874
Mammalia - Hyaenodonta - Hyaenodontidae
cf. Hyaenodon sp. Laizer and Parieu 1838
Peradectes sp. Matthew and Granger 1921
Herpetotherium valens (Lambe 1908)
see common names

Country:United States State/province:California County:San Diego
Coordinates: 32.9° North, 117.0° West (view map)
Paleocoordinates:32.0° North, 105.8° West
Basis of coordinate:based on nearby landmark
Altitude:290 meters
Geographic resolution:outcrop
Period:Paleogene Epoch:Eocene
10 m.y. bin:Cenozoic 3
*Period:Tertiary *Local age/stage:Late/Upper Duchesnean - Early/Lower Chadronian
Key time interval:Duchesnean - Early/Lower Chadronian
Age range of interval:40.40000 - 33.90000 m.y. ago
* legacy (obsolete) database fields
Stratigraphic resolution:bed
Stratigraphy comments: said to be late Duchesnean to early Chadronian
"about 10 m above the base of the upper member" (Walsh 2010)
Lithology and environment
Primary lithology:gray,green silty mudstone
Lithology description: "Locality 4041 consists of a single large rip-up clast of purplish and greenish mudstone occurring within a pale gray cobble conglomerate... almost certaintly derived from an immediately underlying, laterally extensive bed of pale greenish gray siltstone and mudstone up to 1 m thick, from which Locality 4042 was collected" (Walsh 2010)
Environment:terrestrial indet.
Modes of preservation:body
Size of fossils:mesofossils
Collection methods and comments
Collection methods:bulk,chemical,sieve
Minimum sieve size:0.600
Rock censused:4160 kg
Reason for describing collection:general faunal/floral analysis
Collection method comments: SDSNH collection
"Approximately 360 kg of matrix from [4041] and ~3800 kg of matrix from [4042] were screenwashed using 30-mesh screens (0.6 mm square openings)... concentrates were processed... using the heavy liquid tetrabromoethane"
Also known as:SDSNH 4041, 4042; Upper Pomerado Conglomerate
Database number:17039
Authorizer:J. Alroy Enterer:J. Alroy
Modifier:M. Uhen Research group:vertebrate
Created:1999-09-21 00:00:00 Last modified:2019-05-28 18:50:22
Access level:the public Released:1999-09-21 00:00:00
Creative Commons license:CC BY
Reference information

Primary reference:

3545. S. L. Walsh and R. Q. Gutzler. 1999. A new Mio-Pliocene marine bone-bed from north-central Chile. Journal of Vertebrate Paleontology 19(3):82A-83A [J. Alroy/J. Alroy/M. Uhen]

Secondary references:

34056 S. L. Walsh. 2010. New myomorph rodents from the Eocene of Southern California. Journal of Vertebrate Paleontology 30(5):1610-1621 [J. Alroy/J. Alroy]