A Mystery from Wren's Nest

A number of years ago - and I can't recall how many although it was after 31st October 2004 - I stopped off at Wren's Nest in Dudley (West Midlands) to have a look at the geology there. I have  on many occasions both before and since, hurried past on the M5 with the sight of this splendid piece of upended Silurian seabed  visible in the distance beyond the various advertising hoardings offering  sleeker, sexier and of course more environmentally friendly cars. Yet on this occasion, I simply turned left off the northern side of the M5 and headed for the hills.

It is an exciting place, in a sedate, peaceful and in some respects slightly eerie kind of way. I decided not to park my BMW Z4 (times were good then) in the empty car park on the main road below and chose to leave it on one of the road narrow roads running across the Nest to the small council estate beyond it. I then headed off along the narrow paths.

I spent quite a while wandering about up there feeling, I have to say a little uncomfortable at the apparent remoteness and lack of humans despite being in the middle of a large conurbation. I am a Londoner by birth and to my mind, empty places in cities are dangerous places to be in.

Still, I managed to find a spot on some kind of scree slope that caught the warm sun and I sat down  among the stones regardless of my suit, just to be there.  A casual inspection of the rock chippings that were extensive in the area  revealed a number of interesting finds. Some of these, I took away with me. Now whether this was right of me or not, I don't know. But there you have it.

Now the purpose of this rather extensive preamble is to introduce one of the most interesting fossils in my collection so far. It is Silurian - because it came from the Silurian limestones at Wren's Nest. That's basically all that I know.

It is obviously marine and from the look of it, it appears to have been soft bodied. It was also fairly flat and appears to have feet, spikes or cilia, presumably for movement. In certain light it seems to have an almost granular surface as though it is made up of many segments or perhaps more accurately, cells. These are particularly visible in the picture taken with a flash.(The greyer of the two images was taken with a flash. The other, without.) In shape it is roughly circular with a diameter of approximately 37 mm. Each of the cilia is slightly in excess of 1 mm. There seem to be about 6 cilia to 1 cm where visible around the circumference of the creature. I know of no comparable modern animal and I have seen nothing else like it in internet or documented records nor in any museums that I have visited. then again, I'm no expert so i suppose that someone out there will know.

Dalmanites - Trilobites from Much Wenlock

A number of years ago, I took a few moments - well about a couple of hours to be  precise - out of a busy working week to stop off and the Much Wenlock Museum's geology display with it's model of a Silurian Sea. Armed with a small booklet called Shropshire Geology: A Visitor's Guide (Paperback), I then went in search of trilobites  near a location called Upper Millichope Farm and found these two little beauties in the loose rocks in the bank of a small stream that ran along the roadside in that area.

These two images look pretty much like the Silurian trilobite, Dalmanites mycops and ,as it says in Shrophire Geology, it is  typically only the tail (technically pygidium). We have  the left side pleural region and the axis. Sadly there is no evidence of the slight spike, for want of a better word, at the end of the pygidium.

The second fossil from the same location looks, to my mind slightly different. Again it is only the pygidium but this time we have partial left and right pleural regions as well as axis. Again ,extensive damage, presumably by water erosion has removed part of the pygidium and there is no clarity at the base of the pygidium, which is a pity. I still maintain that the pygidium looks rounder than that of d. mycops and so I am tempted to suggest that this may be a different  species.

Coprolite!

Here are a couple of different coprolites that were found on Shanklin Beach this year. The actual find location was down past the pub below Shanklin Chine and they were located among the pebbles between low and high tide marks.

I don't know much  about coprolites other than that they are fossilised excrement and given that these were found in an area of Cretaceous rocks, it is possible that they are  dinosaur excrement.

The first of these is greyish and has he twisted convolutions that I understand are familiar to meat eating creatures. There are bits of things  in among it that could be small bones or teeth or even feathers.

 

The second is in a brownish matrix, is a more regular 'stone' shape and appears to contain lots of little bits and pieces of black matter that could also be bones. Other shapes are clearly bits of shells and there is one particular area where the serrated edge of a shell is visible.

Not that I am any expert is these matters but my assessment would be that the grey twisty one was deposited on land and came from a small meat or fish eating creature that lived on land.



The other, I would hazard a guess,  was deposited in the sea or a lagoon by a marine predator feeding on fish and shellfish.

One particular observation that I would make about the darker coprolite is that it has definite flat surfaces which appear consistent with something viscous sitting on a hard surface without the appearance of shear or other slicing. The image below shows some examples of this.

I wonder if there is any formula or rule that can be used to determine the size of the creature that dropped this from the diameter of the coprolite which on this one appears to be around 1.8 to 2.0 cms.

There, who would have  thought that shit could be  so interesting but then I guess you are what you eat!

A Couple of Cretaceous Oysters

My visit to the Isle of Wight in July this year resulted in this find. It is a couple of oyster shells, both fairly complete and stuck together in a fairly usual manner. Upper and lower shells are clearly visible on the lower specimen and they are infilled with sandstone.

The specimen was located  among the rocks exposed at low tide on the beach between Shanklin and Sandown, just below where the railway station of Lake sits near the cliff top. They were wedged in a crevice in the rocks. Total length of the fossil is about 150 cm and width 80 cm at maximum

So what is this Cretaceous Bivalve?

 This is a bi-valve that I found at Yaverland beach on the isle of Wight about 15 years ago. It had been washed out of the soft mud about 100 metres from the tea shop. The only problem is that I can't recall which layer I thought it came from.

Now I had assumed it was cretaceous and after seeing a similar specimen in the Oxford University Natural History Museum I thought it was called Sphera corrugata  or something similar and it was located in the Cretaceous display area. However, on a recent visit to the Museum I noticed that the specimen was no longer on display. A search of the internet has produced nothing of that name and my only reference book on the period, British Mesozoic Fossils, does not include it anywhere.


I would welcome any assistance in identifying this one.

Carboniferous Calamites

On a recent visit to Newcastle, I managed to make a visit to Seaton Sluice. This sadly named village has some interesting outcrops of carboniferous rocks as well as a rather quaint looking harbour which, I presume, is the basis for the word 'sluice'. There's also a pretty good fish and chip shop on the main road there but beware, the fish portions are enormous.

The fossil that I managed to find there is that of a couple of segments of a calamites stem from about 309 mya. Calamites are horsetails but unlike their modern counterparts, these were tree like and grew to around 30 metres. The stems of calamites, like their modern counterparts were hollow, rather like bamboo for example (unrelated). These hollow stems tended to fill with material to form , over the millions of years, casts of the inside of the plant. I believe that the fossil that I collected  is of this kind and shows the internal ribbing of the stem. There were a number of splendid fossils of the stems or possibly roots that were visible in the rocks and I have  included photographs of those as well as they look splendid and will probably be destroyed by wave action over the next several winters.

The first image is longitudinal showing the ribbing and the two segments. The second is transverse showing the infill and the vestiges of the outer layer on the far left.The third  is the reverse of the fossil and matrix showing additional stems.

The following images are taken from the rocks in situ and just below a walkway and steps. You can see fairly extensive stem, root or rhizomes in the matrix. Notice also that many of the  pieces are smooth rather than ribbed and  mostly do not appear to be segmented. You can also see the relative thickness of the stem wall in the third of this set of images (which sadly is a little out of focus).

These were all located in one outcrop and all within a metre of each other. In the short amount of time afforded to me (it was an hour from high tide and the waves were splashing up at my back) I didn't find any other similar fossils in the vicinity. perhaps a more leisurely search would have revealed better evidence

    

Cretaceous Ammonite

So what's unusual about an ammonite?  After all they seem to pop up everywhere and this doesn't even look like an ammonite!

This is (at least to me)  an unusual ammonite find from the Shanklin - Sandown area of the Isle of Wight. It was found on the high tide mark among the pebbles on the beach in early July 2014. Naively I thought it was some kind of dinosaur bone at first but this was dismissed with the kind assistance of the folk at the Sandown Museum.

 

In fact it is the cast of an reasonably large ammonite chamber. The creature died between 116 and 133 mya (Lower Cretaceous - Aptian to Barremian)

In life it would have swum about like a modern day nautilus and from the outside would have  looked like a larger version of the ammonites that will appear on other posts shortly.

Once it had died it would have fallen to the sea floor where the contents of its shell would have rotted as the remains of the creature lay on its side. Sand would have  covered the shell and would have seeped into the chambers within. The  ammonite would have been eroded by the sea  on its upper surface, which presumably explains some of the asymmetry of the fossil, until it is fully covered by sand. After millions of years the shell would probbaly remain in place until it fell out of the cliffs or was exposed by wave action on the foreshore. Once this happens the shell would disintegrate and the hardened inner chamber infills then separate. One of these is what I found on the shoreline between Shanklin and Sandown.

The  rock apparantly comes from the Ferruginous Sands that make up the tall cliffs that run along Sandown Bay to Shanklin and on which at one point the Isle of Wight Railway runs, it seems from the sound  of the passing train as it echoes at the foot of the cliffs below, perilously close to the edge near Lake.

What I find particularly interesting about it are the various notches in it that were presumably for ligaments or vessels of some kind. There are quite a few on what I take to be  the inner surface and fewer on the outer, including a single central one in the middle of the outer surface.

I owe the background and explanation of this fossil to Trevor Price , the Community Learning Officer of the Dinosaur isle Museum and I hope that he won't mind me mentioning him here.