Featured Paleontology Projects

SR-41 Kettleman City Rehabilitation

SR-41 Kettleman City Rehabilitation

Cogstone conducted paleontological monitoring during the six months of excavations in the Tulare, San Joaquin and Etchegoin Formations. Nine fossil localities in 18 beds were discovered during excavations – one in the Tulare Formation, seven in the San Joaquin Formation, and one in the Etchegoin Formation. Approximately 800 fossils, almost 600 of which were identifiable to family or genus level, were recovered. Plant fossils were recovered from the San Joaquin and Etchegoin Formations. Invertebrate fossils were recovered from the Tulare, San Joaquin, and Etchegoin Formations. Vertebrate...

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Exploratory Shaft at Fairfax Station

Exploratory Shaft at Fairfax Station

Excavations of an 18 ft. by 36 ft. shaft extended from the surface to 75 ft. down in order to determine the characteristics of the asphalt-rich sediments at depth to assist in planning and executing the construction of the subway station for the Purple Line Extension. Over 500 fossils were recovered. All except one of the fossils recovered came from the near-shore marine San Pedro Formation. The majority of fossils recovered were invertebrates, primarily clams, snails and tusk shells. Vertebrate remains were rare and consisted of ray teeth, a large marine mammal rib fragment, and a...

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SR-99 Arboleda Drive Interchange

SR-99 Arboleda Drive Interchange

Paleontological monitoring was required below the surface Holocene alluvium in the Modesto and Riverbank Formations. Cogstone’s field director and multiple monitors were present to ensure coverage of multiple pieces of heavy equipment activity. Monitoring resulted in recovery of 1,667 late Pleistocene fossils from 128 localities. They included a significant mammoth specimen as well as a variety of large and small mammals, birds, reptiles, and fishes. The presence of bison and dire wolf together indicates the fossil fauna is within the Rancholabrean Land Mammal Age. The fossils are curated at...

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