Found a fossil.

[Fishing With Franco]

Found this in New Melones lake in Angeles Camp California. The lake was very low and we found a few fossils. Is this common here? How old is it? I’m pretty sure it’s an Ammonite. The last pic is some sort of fin or wing maybe? It’s only 3 inches long. Thanks in advance.

[Creek - Don]

That is an imprint of Jurassic Ammonite called Cadoceras, I think.   There are some Jurassic formation in that lake area so marine fossils can be found.  

[Rockwood]

30 minutes ago, Fishing With Franco said:

The last pic is some sort of fin or wing maybe? It’s only 3 inches long.

Was it found near the ammonite or down slope at least ? I think it may be a fragment that weathered away earlier.

[abyssunder]

I agree that's an ammonites preserved in the matrix, but some of the pictures show there are two different erosional instances. One shows the external side, the other shows the internal side of the chambered structure.

[Thomas.Dodson]

The primary exposures there are the Mariposa Formation which would be late Jurassic. The rock exposures pictured fit very well with the description of the Mariposa as well. I'm not sure on the ammonite but multiple species of Perisphinctes are reported from the Mariposa of California as well as Amoeboceras dubium.

 

https://pubs.usgs.gov/pp/0374d/report.pdf

 

The presence or absence of the bivalve Buchia concentrica would help narrow it down.

Cont.