28 Dec 2013

Segmented sessile lower Jurassic fossil (ID needed please...updated)

Alright, I'm stumped. (That's what you get when you lend your precious fossil field guides to a forgetful neighbour.) Our Boxing Day walk on Runswick beach turned up a some ammonites, a few bits of belemnites, a piece of jet and a couple of devil's toenails.And this, or rather these since it's obviously a colony of them:

Update; thanks to AndyS and Anon, it turns out they're geological artifacts not fossils. They are cone in cone structures, their origins a matter of debate. While not what I had hoped, finding them caused me (and Number One Field Assistant) some delight, I have learned something and will look at strange shapes in the rocks with a new, skeptical eye in future.

Any ideas, do leave a comment. And click over to Andy's Fossils. How have I not found this brilliant ammanoblog before? He's a proper collector who cracks open nodules and having found lovely fossils prepares them meticulously then writes about it all very well indeed. Go and see him. At once.


Anonymous said...


Google for "cone-in-cone structure" and you'll find your "fossil"...

Best regards,
Andy (andysfossils.com)

Stu Pond said...

These are cone-on-cone structures and are the result of diagenitic processes and acre non-organic. Great example!