# Identify these fossils/minerals **URL:** \ **Category:** Factual Questions\ **Created:** [July 31, 2006, 1:42am UTC](https://boards.straightdope.com/t/identify-these-fossils-minerals/366642 "2006-07-31T01:42:20Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [July 31, 2006, 1:42am UTC](https://boards.straightdope.com/t/identify-these-fossils-minerals/366642/1 "2006-07-31T01:42:20Z")
I just returned from a camping holiday in North Yorkshire and a couple of days of this was spent on the remarkable beaches there; much of the coastline includes jurassic limestone, shale and clays, so we did find a few fossils, including ammonites, belmnites and a beatiful sea-worn boulder of some hard, deep red red stone that was uniformly studded with perfect bivalve shells - unfortunately, this was so large it could only just be moved by hand, so I was not able to bring it home. Anyway, we spent the last day at Reighton Sands, right in front/on top of the famous Speeton Clay - my son found an excellent ammonite imprint, and there were many people hacking and digging at the cliffs - mostly pulling out fairly soft, crumbly specimens and destryong them in the process - I confined myself to searching the beach and foreshore. I returned with a number of interesting pieces, but here are a few that I can’t quite identify. Specimen 1: [front](http://www.gurman.co.uk/rocks/1a.jpg) and [back](http://www.gurman.co.uk/rocks/1b.jpg) I’m aware that certain nonliving mineral growths often give rise to ferny or feathery formations and this may be simply one of them, however, it is quite a substantial formation within the stone; the ‘stalk’ part runs right through the piece and forms the small semicircular shape on the back Specimen 2: [front](http://www.gurman.co.uk/rocks/2a.jpg) and [end](http://www.gurman.co.uk/rocks/2b.jpg) This one looks more impressive in real live than as depicted here; it’s a hard greyish pebble that, when viewed from the end, bears a very regular, perhaps even concentric, pattern of polka-dots, however, the worn sides of the pebble show that these dots are in fact the ends of cyclindrical structures that go all the way through the piece. Specimen 3: [front](http://www.gurman.co.uk/rocks/3a.jpg) and [end](http://www.gurman.co.uk/rocks/3b.jpg) At first glance this one looks just like a piece of sedimentary rock, however the striations within it are quite regular - more like woodgrain or the tooth of a large herbivore, especially on the end view. Plusthere was nothing else remotely like it nearby. It may just be a bit or innocent rock though. Can anyone assist with identification of these? Particularly the first two. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [July 31, 2006, 5:16am UTC](https://boards.straightdope.com/t/identify-these-fossils-minerals/366642/2 "2006-07-31T05:16:45Z")
Except for size, 1 looks a lot like an impression from the spinal plates of one of [these Megasaurs](http://www.xofacto.com/justin20/shinzen-godzilla-62.jpg). OTOH, Godzilla’s plates also resemble the [suture lines of some Ammonites.](http://en.wikipedia.org/wiki/Image:Haeckel_Ammonitida.jpg) Can you tell if the pattern extends into the rock? If it’s just on the surface, you might be looking at a scar from a [modern holdfast](http://www.adelaide.edu.au/sciences/env_biol/images/Postgrad%20images/HOLDFAST.jpg). [Crinoids had holdfasts too](http://www.uky.edu/OtherOrgs/KPS/images/holdfast.jpg) but, for what it’s worth, I’ve never seen one that looked like that. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [July 31, 2006, 7:28am UTC](https://boards.straightdope.com/t/identify-these-fossils-minerals/366642/3 "2006-07-31T07:28:44Z")
As far as I can tell, the only part of specimen 1 that extends through the rock is the ‘stalk’; the ‘fronds’ are not unmeasurably thin, but judging from the appearance of the part where they extend over an eroded edge (top right), they are no more than a few millimetres thick. All observable features of the specimen are consistent with it being composed of about five or so fairly thin feathery fronds branching radially from a central stalk - of course there’s no easy way to tell how much of the original structure is still present; we may be looking at a very small slice of something much bigger. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [July 31, 2006, 2:56pm UTC](https://boards.straightdope.com/t/identify-these-fossils-minerals/366642/4 "2006-07-31T14:56:38Z")
Specimen one does strongly resemble an ammonite suture like **Squink** says. It appears to be eroded to the point where none of the original architecture remains, just an oblique, non-representative portion of the original.