Hi. I went fossil hunting for my birthday on Saturday for carboniferous fossils in Ossett West Yorkshire, UK.
When I was just about to leave, I found my best trigonocarpus nut ever. It is one of my biggest ones ever and my first complete one ever.
Here are the fossils which I found:
Middle: crystallised rocks
Right: Calamites root
Left: Artisia root?
Middle: trigonocarpus nut
Right: fossil wood (I found much more but I've only showed a few of them in the picture)
Please correct me if any if my IDs are wrong.
Just a couple of comments:
- The Artisia we're still thinking about (as in previous topic).
- For rocks in which you can see crystals, you should, in general, use 'crystalline' not 'crystallized'. 'Crystallized rock' implies the rock as a whole crystallized - from a molten state or from a solution. In many cases, that will not be true. The crystals in many sedimentary rocks, for instance, arose from deposition of particles of other rocks (which happened to be crystalline) plus the deposition of mineral crystals in the pore spaces (from chemicals dissolved in pore fluids). On top of that, recrystallization may have occured, modifying the earlier crystals (that may occur in diagenesis or metamorphism).
Hi again. I managed to video some of my finds on this trip.
The first one is a Calamites (which is on the top left in the original picture), and the other one is the trigonocarpus nut.
Sorry they are not very clear, I videoed them on my phone but it couldn't post them on my phone so I had to vidio them on my ipad from my phone.
Back to the possible Artisia...
The closest I have found is some types of rugose coral (like Hippurites), though I have not been able to find a good photo. The best I can do is this engraving - http://www.fossilmuseum.net/fossil-art/cnidaria/rugosa2.jpg
It has the right sort of mesh pattern, but it seems to be lacking the interwoven aspect of your specimen.
Dan, maybe you could check: am I inventing the interwoven nature of the structure from looking at your photo, or does it really exist? Maybe you can look closely at your specimen and tell me.
Yes, the tree and plant fossils suggest a non-marine environment.
(So coral is not particularly likely; quite right.)
That is OK as a generalization. Just bear in mind:
- The environment where organisms lived can be different from the one where they became finally deposited (plant material is washed from deltas and can be deposited in a marine environment, eg.).
- Even a thin band of rocks can represent quite a large period of time, during which the environment can vary quite a lot (and it is complicated by hiatuses - periods not recorded in the rocks because of erosion or non-deposition). Even though a stratigraphic unit, such as the Coal Measures, may have a simple name, it may entail a range of lithologies and environments. For instance, although there may have been times when plants flourished on land/swamps, occassional submergence could easily allow the same area to see deposition of marine sediments and associated fossils. When you see an outcrop composed of different rock types, you are probably looking at manifestations of different environments.
In an area known for plant fossils, marine fossils may be uncommon. But they can occur, and can be be of special interest, resulting in papers being written about them. By way of an example, here are a couple concerning the Coal Measures.
'Marine horizons in the coal measures of south Wales'
Trueman, A. E., 1928
"Marine beds, some with abundant faunas, occur in the Anthra-comya pulchra zone at Cwmgorse, near Swansea, and in Yorkshire. Possible marine beds also occur at lower horizons in the former locality; they contain Orthoceras, Orbiculoidea, Lingula and other typically marine organisms."
'Lingula Horizons in the Coal Measures of Northumberland and Durham'
William Hopkins, University of Durham
Geological Magazine, Volume 71, Issue 04, April 1934, pp.183-189
"Previous to 1858, the Northumberland and Durham Coalfield was considered to be destitute of any fauna other than the usual non-marine type. In 1858, J. W. Kirkby gave the first indication of marine fossils in this coalfield. He obtained specimens of Lingula credneri (Geinitz) from shales some 17 feet above the Five-Quarter seam during the sinking of a shaft at Ryhope, 3 miles south of Sunderland (9). Some of these specimens are figured by T. Davidson (2)."
Your area, Ossett, has been under water. The BGS describes the Pennine Middle Coal Measures Formation as "swamps, estuaries and deltas. These rocks were formed in marginal coastal plains with lakes and swamps periodically inundated by the sea; or estuaries and deltas, and shallow seas". That is just the bedrock exposed at the surface. There are older rocks below and there were younger rocks above (since removed by erosion), some of which were probably also deposited in marine environments (although we know many were not).
Just looking through some old books and I came across something that looks like the specimen that Dan has found.
I will probably be wrong but it looks like a referance to a fossil found in the Silurian around the New York area,
It is a reasonable thought, thanks; especially as Syringopora is recorded from Yorkshire.
But I don't think it flies.
Dan's specimen has a fairly regular pattern of vertical and horizontal struts, whereas the structure in Syringopora is somewhat random horizontally; also in Dan's specimen the struts are narrow and probably solid, whereas in S. they are thicker (relative to the gaps between) and more tubular.
I've been trying to find an example of a plant with woody vascular bundles arranged in the right sort of structure, but without luck. (You may have noticed on old Antirrhinum (snapdragon) stems, there is a perforated woody inner part that remains for a while as old plants decompose; Broccoli and wallflower, likewise.)
By all means consider sending it to the NHM, but contact them first for advice (they may get a palaeontolgist to have a look at the discussion, which might give result in an ID).
Also, just because I and other viewers here don't recognize it, it doesn't mean it is a new species. I've been doing geology for over 40 years, and I still find plenty of stuff new to me but known to others.