Retired PaleoServices Field Paleontologist Richard Cerutti discovers the site. Curator of Paleontology and Director of PaleoServices Dr. Tom Deméré and PaleoServices Field Paleontologist Brad Riney meet with Richard at the site to formulate plan for excavation of the fossils.
November 16, 1992
Formal excavation of the site begins.
November 17, 1992
Caltrans archaeologists visit the Cerutti Mastodon Site and help screen sediment from disturbed area.
November 18, 1992
Steve’s Horse Quarry discovered and excavated over next nine days.
November 19, 1992
Dr. Tom Deméré begins videotaping/documenting the Cerutti Mastodon Site.
December 3, 1992
Paleontologist Dr. Larry Agenbroad visits the Cerutti Mastodon Site for the first time.
December 19, 1992
SDSU Geologist Dr. Pat Abbott visits the Cerutti Mastodon Site for the first time.
December 24, 1992
Dr. Larry Agenbroad and Paleontologist Dr. Jim Mead join the excavation team for one week of field work.
December 28, 1992
Dr. Tom Deméré videotapes the Cerutti Mastodon Site.
December 29, 1992
Former PaleoServices Field Paleontologist Steve Walsh mentions discussion with Larry and Jim about a Sangamonian versus Wisconsinian age for the Cerutti Mastodon Site.
December 31, 1992
Dr. Tom Deméré videotapes the Cerutti Mastodon Site.
January 4, 1993
National Geographic Society awards emergency grant of $14,038 to support field work and travel.
January 14, 1993
Dr. Larry Agenbroad returns to San Diego for two-day visit.
January 23, 1993
Dr. Tom Deméré videotapes the Cerutti Mastodon Site.
January 25, 1993
SDSU Geologist Dr. Tom Rockwell visits the Site and suggest an age of 300 ka +/- one interglacial (i.e., 200 ka to 400 ka) based on elevation, caliche volume, and degree of modern soil development.
January 27, 1993
CM-423 cobble found in Unit G-5 at the Cerutti Mastodon Site.
March 22, 1993
Dire wolf skeleton discovered.
April 5, 1993
Column sample of quarry stratigraphy jacketed in northwest corner of Unit F-5 at the Cerutti Mastodon Site.
April 21, 1993
Steve Walsh collects OSL samples from north wall of Unit B-6; last day of field work at the Cerutti Mastodon Site.
April 27, 1993
Cerutti Mastodon Site buried by bulldozer.
April 28, 1993
Richard KU (USC) calls Dr. Tom Deméré with preliminary radiometric results and date of ~190 ka on caliche sample.
December 29, 1993
USC Geologist Dr. Richard Ku sends letter report with radiometric (U-Th) dating results.
January 7, 1994
State Route 54 Paleontological Mitigation Report submitted to the California Department of Transportation (Caltrans).
March 20, 1995
Archaeologists Dr. Steve Holen and Kathleen Holen first research visit to San Diego Natural History Museum to examine the fossils and artifacts salvaged from the Cerutti Mastodon Site.
February 2, 2008
Conference on Cerutti Mastodon Site held at San Diego Natural History Museum. Attendees included Dr. Tom Deméré, Richard Cerutti, Dr. Steve Holen, Kathleen Holen, Dr. Dan Fisher (paleontologist and mastodon expert), Dr. Tom Stafford (archaeologist and dating expert), George Jefferson (paleontologist and Pleistocene expert), Dr. Steve Forman (OSL dating expert), Dr. Pat Abbott, and Dr. Mark Becker (archaeologist and lithic expert).
May 28-29, 2009
Trench excavated into the south side of the sound berm directly opposite the Cerutti Mastodon Site to collect fresh sediment samples for OSL dating.
May 28, 2009
First Cerutti Mastodon Site samples sent to Dr. James Paces, geologist and geochronologist at the U.S. Geological Survey.
May 16, 2011
Initial radiometric (U-Th) dating results reported to the Cerutti Mastodon Team.
February 18, 2012
Dr. Jim Paces and Dr. Steve Holen visit the San Diego Natural History Museum to identify additional samples for dating.
April 2012
Two Cerutti Mastodon Site rock specimens (CM-254, 383) sent to Australia for use-wear and residue analysis. Initial contact with Archaeologist Dr. Richard Fullagar.
October 5, 2012
Dr. Jim Paces prepares multiple specimens and performs digestions, chemical separations and purifications, and completes isotope analyses on nearly 100 individual subsamples.
July 2012 to December 2014
Dr. Jim Paces compiles and evaluates all data using newly published numerical age models that consider diffusion, absorption, and decay of U in bone.
January to April 2015
Geoarchaeologist and Soil Scientist Dr. Jared Beeton visits the San Diego Natural History Museum for first time to examine Cerutti Mastodon Site collection and obtain sediment samples and soil descriptions.
February 2015
Final age determination for the Cerutti Mastodon bones of 130,700 ±9,400 years is reported to the Cerutti Mastodon Team.
May 2015
Initial submission of Cerutti Mastodon Site manuscript submitted to the prestigious science journal Nature.
March 17, 2016
Formal acceptance of Cerutti Mastodon Site manuscript by the science journal Nature.
March 13, 2017
