ID request-probable Late Cretaceous, shallow seabed marine fossils

[Shelley Rogers]

I am new to fossil hunting, but I’ve always been a beachcomber and rock hound. I recently visited Sunset Cliffs in Point Loma,  in San Diego, California.

https://goo.gl/maps/csoVaYRvBr9556AJ7

As my husband surfed below, I remained atop the bluffs, where these sun-bleached relics kept demanding notice. Along with easily identifiable shells were a few items that I’d love to know more about.

 

 

[Tidgy's Dad]

I'm pretty sure those are chiton segments. 

[Shelley Rogers]

YES! You’re absolutely right. Thank you for filling in the blank.

[jpc]

yes... chiton plates

[JamieLynn]

are they fossilized?

[abyssunder]

Amazing ID! 

[Shelley Rogers]

So, JamieLynn’s question is valid: are these fossils? The last, and largest piece, feels like rock in heft and thickness. The rest seem just like modern seashells, only they’re from caches atop bluffs that are 20 to 40 feet above the beach. They are found in generous outcroppings that are loose and sandy, not like hardened stone that must be chipped away. In fact, the city is making a desperate attempt to preserve the cliffs, as they are in jeopardy of being reclaimed by the ocean, due to runoff erosion.