Turritella Snail Bed

Turritella Snail Bed. Fossil Snails Tell Their Story in These Rocks. Within a three-foot thick sandstone bed, seen on both sides of the trail, is a layer of rock containing fossil Turritella aedificata snails. Note the slender tapered shape that has led to calling them “Tower Shells.” They are also characterized by having seven or eight cols or “whorls.” During their life, the snails crawled along the ocean bottom and are algae. Turritella are ancestors to some modern snails., The rock layers (or beds) were originally formed in a horizontal position, but as Mount Diablo uplifted the beds were tilted 90 degrees. Now you see the upturned eroded edges of the beds. Geologists estimate the age of these sedimentary rocks to be approximately 45 million years old., Why are fossils important? , Fossils are found in sedimentary rocks, like the sandstone at this panel, and give us valuable information about Earth’s history. They tell us about the animals and plants that lived on Earth through geologic time. They help us understand past climates, provide clues to past events, and help us date the age of rocks and the environment in which the rocks were formed., Thus, Turritella has helped geologists better understand the geologic history of Mount Diablo. . This historical marker was erected by California Department of Parks and Recreation. It is in Danville in Contra Costa County California