Spring Canyon (Eocene to of the United States)

Also known as SDSNH 4041, 4042; Upper Pomerado Conglomerate

Where: San Diego County, California (32.9° N, 117.0° W: paleocoordinates 32.0° N, 105.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Pomerado Formation, Duchesnean to Duchesnean (40.4 - 33.9 Ma)

• said to be late Duchesnean to early Chadronian

•"about 10 m above the base of the upper member" (Walsh 2010)

• bed-level stratigraphic resolution

Environment/lithology: terrestrial; gray, green, silty mudstone

• "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)

Size class: mesofossils

Collection methods: bulk, chemical, sieve

• 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"

Primary reference: 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]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 17039: authorized by John Alroy, entered by John Alroy on 21.09.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

Mammalia
 Primates - Microsyopidae
Uintasoricinae indet. Szalay 1969 primate
 Rodentia -
Nonomyinae indet. Martin 1980 rodent
said to be new
Nonomys gutzleri n. sp. Walsh 2010 rodent
said to be new
 Rodentia - Eomyidae
cf. Paradjidaumo sp. Burke 1934 rodent
Protadjidaumo sp. Burke 1934 rodent
cf. Metanoiamys sp. Chiment and Korth 1996 rodent
 Rodentia -
cf. Griphomys sp. Wilson 1940 rodent
said to be new
 Rodentia - Heliscomyidae
Heliscomys sp. Cope 1873 rodent
 Rodentia - Ischyromyidae
Ischyromys sp. Leidy 1856 rodent
 Lipotyphla - Geolabididae
Centetodon cf. magnus Clark 1936 placental
 Perissodactyla - Equidae
Mesohippus sp. Marsh 1875 anchitheriine horse
 Carnivora - Mustelidae
Mustelidae indet. Fischer 1817 mustelid carnivore
 Ungulata - Camelidae
Camelidae indet. Gray 1821 camel
 Ungulata - Agriochoeridae
? Agriochoeridae indet. Leidy 1869 agriochoerid
 Ungulata - Hypertragulidae
cf. Hypertragulus sp. Cope 1874 ruminant
 Hyaenodonta - Hyaenodontidae
cf. Hyaenodon sp. Laizer and Parieu 1838 eutherian
 Theriiformes - Peradectidae
Peradectes sp. Matthew and Granger 1921 metatherian
 Theriiformes - Herpetotheriidae
Herpetotherium valens Lambe 1908 marsupial