Fossilized Vertebrae? - Mission Peak, Fremont, CA

[Cory D.]

While descending from the top of our hike up Mission Peak in Fremont, CA, a friend and I came across what we suspect is a fossilized vertebrae.  

After doing some quick research online, I came across the following excerpt:

"Some 3 miles east of the low hills and lying in the Mission District is a much taller ridge, Mission Peak, 2517 feet above sea level. Millions of years before the Pleistocene, sediments that now compose the Mission Peak ridge were deposited by both marine and fresh waters. These sediments are now a rich source of marine fossils, many of them clams and snails. Also, remains of Desmostylus, a mammal with characteristics between those of a sea cow and a walrus, have been found among the remains of seashells. These fossils were buried under marine water during the late Miocene time, or about 12,000,000 years ago. The Miocene is one of seven epochs of the Cenozoic era."

Source: http://cnhm.msnucleus.org/Pleistocene/FossilBearingSediments.html

 

I failed to take a measurement, but as I recall this object was about the size of a lemon.

Can anyone help confirm if this is a vertebrae or provide any additional information?  Thanks for your help!

[DPS Ammonite]

Welcome to the Fossil Forum from an ex SF Bay Area resident.

 

The light stuff looks like an etched limestone. The dark round area looks like a shell rich coarse sandstone all most likely from the Miocene Briones Formation which occurs in the area. Note the texture of the round area is like that outside of the white limestone area. No bone or tooth texture is visible. The only fossils that I see are a hash of marine shells.

 

Keep looking in the Briones, I have seen embedded bones, small fish and shark teeth and vertebrae.

 

If you are interested is learning more about the geology in the area consider joining the Northern California Geological Society, http://www.ncgeolsoc.org/

 

Also look at a great blog about the East Bay geology by Andrew Alden: https://oaklandgeology.wordpress.com/

[Pemphix]

typical etched limestone...