{{Short description|Geologic formation in California, United States}} {{Infobox rockunit | name = San Timoteo Formation | image = | caption = | type = Formation | age = | prilithology = | otherlithology = | namedfor = | namedby = | region = California | country = United States | coordinates = | unitof = | subunits = | underlies = | overlies = | thickness = | extent = | area = | map = | map_caption = }}
The '''San Timoteo Formation''', also called the '''San Timoteo Beds,''' is a geologic formation in California.
== History == Part of the wider San Timoteo Badlands, San Timoteo Formation was initially excavated in San Timoteo Canyon under by a team sponsored by Childs Frick from 1916 to 1921.<ref name=":0">{{Cite news |date=1918-03-07 |title=The Bone Mine |url=https://www.newspapers.com/article/the-banning-record-the-bone-mine/135338030/ |access-date=2023-11-17 |work=The Banning Record |pages=2}}</ref><ref name=":1">{{Cite book |last1=Albright |first1=L. Barry |url=http://california.universitypressscholarship.com/view/10.1525/california/9780520098367.001.0001/upso-9780520098367 |title=Biostratigraphy and Vertebrate Paleontology of the San Timoteo Badlands, Southern California |last2=Kendall, Jr. |first2=Arthur |date=2000-08-03 |publisher=University of California Press |isbn=978-0-520-09836-7 |doi=10.1525/california/9780520098367.003.0001}}</ref>
== Geology == The San Timoteo Formation represents Pliocene and Early Pleistocene sediments, mostly sandstone. The Formation overlies the late Miocene and early Pliocene Mt. Eden Formation (Jack Rabbit Trail & Eden Hot Springs localities, corresponding to the Hemphillian and Blancan faunal stages).<ref name=":1" />
== Fossils == Fossils of Irvingtonian prehistoric mammals were found in the San Timoteo Formation (El Casco, Mammoth and Shutt Ranch localities).<ref name=":1" /><ref>{{Cite web |title=San Timoteo Badlands |url=https://www.utep.edu/leb/pleistnm/sites/santimoteo.htm |access-date=2024-07-22 |website=www.utep.edu}}</ref><ref>{{Cite web |title=Big Pine Citizen 2 March 1918 — California Digital Newspaper Collection |url=https://cdnc.ucr.edu/?a=d&d=BPC19180302.2.28 |access-date=2023-11-17 |website=cdnc.ucr.edu}}</ref><ref>{{Cite web |last=McComas |first=Katie |date=8 May 2019 |title=Paleontological Records Search – Gilman Springs Median and Shoulder Widening Project |url=https://static1.squarespace.com/static/5b7321a489c17291c4fd7b75/t/622b945e6eddcc15103a5a88/1647023200780/PaleontologicalRecordsSearchMemo_May2019.pdf |via=San Diego Natural History Museum}}</ref> These include:
* ''Canis edwardii'' (Edward's wolf) * ''Microtus sp.'' (vole) * ''Ondatra idahoensis'' (muskrat) * ''Mictomys kansasensis'' (bog lemming) * ''Erethizon cascoensis'' (porcupine) * “Plesippus” fracescana (three-toed horse) * ''Equus bautistensis'' (horse) * ''Tapirus merriami'' (tapir) * ''Odocoileus cascaensis'' (deer) * ''Megalonyx sp.'' (ground sloth) * ''Mammuthus'' sp. (mammoth) * Possibly a giant bear (may be either ''Arctodus'' or ''Agriotherium'')<ref name="Scott-1993">{{Cite journal |last1=Scott |first1=Eric |last2=Cox |first2=Shelley M. |date=May 24, 1993 |title=''Arctodus simus'' (Cope, 1879) from Riverside County, California |url=https://ucmp.berkeley.edu/science/paleobios/backissues/v15no2_scott&cox.pdf |journal=PaleoBios |volume=15 |issue=2 |pages=27–36}}</ref>
Fossils have also been recovered from the El Casco Substation locality, which was dated to 1.4Mya. Recovered specimens include ''Smilodon gracilis'', ''Homotherium'', two ground sloths, two types of camels, a llama, horse, and deer. Plant fossils include birch, pine, sycamore and oak trees.<ref>{{Cite web |date=2010-09-24 |title=The Associated Press: Calif. utility stumbles on 1.4M-year-old fossils |url=http://www.google.com/hostednews/ap/article/ALeqM5hUkul_DVGCUiaQPkJB51InmsCnrAD9IC5GN80 |access-date=2024-07-23 |archive-url=https://web.archive.org/web/20100924050705/http://www.google.com/hostednews/ap/article/ALeqM5hUkul_DVGCUiaQPkJB51InmsCnrAD9IC5GN80 |archive-date=2010-09-24 }}</ref><ref>{{Cite web |title=El Casco Substation |url=https://lsa.net/project/el-casco-substation/ |access-date=2024-07-23 |website=LSA |language=en-US}}</ref><ref>{{Cite web |title=Southern California Edison Discovers Most Comprehensive Collection of Fossils of its Era in Southern California |url=https://newsroom.edison.com/releases/southern-california-edison-discovers-most-comprehensive-collection-of-fossils-of-its-era-in-southern-california |access-date=2024-07-23 |website=Edison International {{!}} Newsroom |language=en}}</ref>
==See also== {{Portal|Earth sciences|California|Paleontology|}} * List of fossiliferous stratigraphic units in California * Paleontology in California
==References== {{Reflist}} * {{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= https://www.fossilworks.org/|access-date= 17 December 2021|archive-date= 25 March 2022|archive-url= https://web.archive.org/web/20220325060448/http://www.fossilworks.org/cgi-bin/bridge.pl?action=home|url-status= dead}}
Category:Geologic formations of California
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