Piedra de las conchitas

That's the devil's toenails, right? It has a bunch of names, but that's the one I remember. Cool looking!

Bet that polishes up pretty with some nice contrast, too.

The more I look, the less I think shells and see crinoids. No?

That's a nice one Scott. Glad you had good luck finding some! Technically, since those are tiny clams, Coquina is usually the ID term used but it is also sometimes called Pt. Mugu Shell Rock. Devil's Toenails is more correctly applied to the Texas fossil rock that contains little Oyster fossils by that name. The California stuff is variable in hardness but the better pieces take a pretty good polish. Here's a cab of the CA Coquina vs the similar Indian stuff. No crinoids, rocks wrong age, much younger. That's just the way your saw hit the various clams. There are gastropods present in some too.



Devil's Toenails with the little Grypha type oysters

aDave

Not far from Turner's outdoorsman in oxnard

Hi Scott, yes, please find a link to this this recent thread/post

I also see Crinoids. These rocks are pretty typical of the Carboniferous Limestone that we find over here. In fact I noted some on the top of the mountain I ran recently (all the photos expand if you click them).

Here in the England, the limestones can polish up quite well, but these fossils tend to be relatively soft and break easily unless they are found in chert nodules; they're generally kept as fossil samples. In the USA you seem to have many of our soft rocks infused with silica rocking the hardness up a step and making the rocks more resilient.

ETA just a bit more regarding assemblages - I believe these are generically called fossil assemblages and can be classified (such is the nature of the human) into life assemblages or living assemblages and death assemblages.

Yes - hence bio-stratigraphy works so well at providing relative ages of rocks & we can correlate the various bands across the globe despite different thicknesses / depositional environments / matrix colour-chemistry etc!

*sigh* Again, those deposits are not old enough to have crinoids. Primarily small clam shells and such. The formation that material comes from is Miocene in age, much newer rocks than those containing crinoids which mainly died out in one of the earlier mass extinctions. There are still a few living criniods but not likely to be in those shallow water clam beds, mainly free swimming or deep water critters.....Mel

Sabre52

Would you help identify these features?

Not just the big one, but at least three smaller ladder shaped ones. I can't see how they are bivalves.

Chas this isn't limestone. Steel won't scratch it.
metalsmith