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Showing results for tags 'great limestone'.
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Spines on silicified Latiproductus, Mississippian, England.
TqB posted a topic in Member Collections
Probably Latiproductus latissimus, Great Limestone, Mississippian, Pendleian Stage, Co. Durham, England. I've dissolved out a few silicified partial shells of this common large productid but these are the first attached spines I've come across so far. I can't find any literature where these have been figured before for this genus. Four are showing; there may well be more but the piece is very fragile and I'm stopping here! They only occur on the ventral (pedicle) valve, judging by the spine bases. The second photo is of a more complete ventral shell in the same piece, with typical spine bases. Scale in mm Usual preservation after acid extraction in this bed. (55mm across, quite small for the species.)- 8 replies
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- 8
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- brachiopod
- Durham
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Does anyone recognise this? It's in a piece of Mississippian Great Limestone (north east England) that I'm acid dissolving for silica replaced fossils. It's about 7mm long and I'm stumped. I don't think it's bryozoan - no sign of branches or zooecia and we don't have Archimedes which it vaguely resembles. Foraminiferan? It has a resemblance to strings of Saccaminopsis (calcareous alga spheres) that also occur but they don't have the twist. Scale in mm In context, with brachiopods, brachiopod spines, corals, gastropods
- 9 replies
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- 3
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- barley twist
- Durham
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Silicified rostroconch, tiny but complete, Mississippian, England
TqB posted a topic in Member Collections
I've always wanted to find a rostroconch in my local Mississippian rocks of N.E. England (or indeed anywhere) but never have. There's a handful of records from the area but they're very sporadic. I've finally struck lucky, very unexpectedly, in a a sample from the Great Limestone (upper Missisippian, Pendleian Stage) that I've been dissolving for silicified fossils. This is full of small brachiopods, gastropods, corals and various other stuff, all interesting but mostly predictable. Anyway, this turned up a few days ago and is instantly recognisable, despite being only 4mm long and preserved in typical sugary silica particles. Presumably Conocardium (like the few records), it has a very long rostrum preserved and the ribbing is apparent in the closeups. 4mm long Long rostrum on left, short main shell on right. With a similar though larger Permian one (photo flipped). Figure from Mazaev, 2015, "Middle Permian rostroconchs of the Kazanian stage of the East European Platform" Ventral view, rostrum pointing upwards, gape below. Posterior (rostrate) end, concentric ribs on shell below. (mm scale) Anterior (gape) end, again showing ribs either side.- 4 replies
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- 10
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- Carboniferous
- Co Durham
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Micro heteromorphic silicified ?gastropod ?microconchid Mississippian, England
TqB posted a topic in Fossil ID
Does anyone recognise this tiny silicified shell? It's about 2mm long. I haven't seen one like it before from the Carboniferous. From the Great Limestone (upper Mississippian, Pendleian Stage) from Weardale, Co. Durham, England. From a piece I've been dissolving in acid, containing silicified brachiopods, gastropods etc. It starts off with an open helical spiral (3rd photo) and then straightens out. It also has clear annular ribs. Although the preservation is imperfect and sugary, I'm sure it's shell replacement rather than internal mould, judging from other fossils in the pece. The various serpulid-like gastropods and microconchids I've come across elsewhere don't have the regular ribbing.- 4 replies
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- 6
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- aberrant
- carboniferous
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Does anyone recognise this? I noticed it when scanning photos of a recently cut and polished piece of Frosterley "Marble" from Weardale, Co. Durham, UK. (upper Mississippian, Pendleian). It shows in section as a rod about 5mm long, with perforations, central ridge and a fine reticulate pattern. My first thought was a Fenestella fragment but it doesn't look regular enough and I can find no mention of the reticulate structure. Also, I've never seen bryozoans in this part of the limestone though they occur at other levels. Now I'm wondering about a dasycladacean alga - some look vaguely similar but all the Carboniferous ones I can find references to look simpler and fuzzier. Scale bar is 1cm, divisions are 1mm Contrast enhanced In context, showing ghostly appearance amongst the corals
- 11 replies
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- alga?
- fenestellid?
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A very common genus, ranging from Ordovician to Upper Carboniferous to ?Permian. This specimen shows good internal detail of the narrow corallites (1.2 - 1.5 mm), including septal spines which are not diagnostic and may not always be present (this may be preservational). The long, infundibuliform (funnel shaped) tabulae are characteristic and show in some of the longitudinal sections. Scale bar 1 cm long.
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- alston formation
- carboniferous
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(and 5 more)
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From the Great Limestone, Pendleian (Upper Mississippian) of County Durham, UK. One for @Spongy Joe and any other sponge experts out there. There appear to be no sponges (apart from Chaetetes) recorded from this well researched limestone but I've collected over thirty over the past few years. There are several different types, generally fossilised as broken fragments though these can be quite large (several inches across). This one is a curved sheet, like part of a vase or dish, about 10 - 15mm thick. The outer (convex) layer contains a good proportion of spicules showing five (and a few six) rays so could it be a heteractinid of some sort? The preservation is mostly calcite, perhaps original. Scale bar is 1cm long. Vertical section, showing disposition of tangential sections below. (specimen no. Sp. 13) Tangential section, cutting through outer surface on right and bottom (the orange layer, with smaller spicules than the internal ones). Closeups of tangential sections. Several five rayed spicules are visible along the edges (i.e. in the outer layer).
- 32 replies
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- 1
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- county durham
- great limestone
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From the album: corals
Section just below top of the calice, showing central lamella and other axial structures continuing into central boss. Great Limestone, Weardale, County Durham, UK.-
- bipartitum
- carboniferous
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From the album: corals
Section showing incomplete central lamella. Great Limestone, Weardale, County Durham, UK.-
- bipartitum
- carboniferous
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From the album: corals
Section showing incomplete central lamella characteristic of the subspecies konincki. Great Limestone, Weardale, County Durham, UK.-
- bipartitum
- carboniferous
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From the album: corals
"Standard" D. bipartitum section showing complete central lamella. Great Limestone, Weardale, County Durham, UK.-
- bipartitum
- carboniferous
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Characteristic of the Upper Visean and Lower Namurian of Europe and Africa. Easily identified by its compact, cuspidate axial column made of small tabellae. One of the less common solitary corals in the Great Limestone, this one is in a dark matrix locally known as "Frosterley Marble".
- 4 comments
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- alston formation
- aulophyllum
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Partly preserved in what I think is ferroan dolomite, with clear calcite in the voids which allows a 3D view of the structure in places. A common cerioid coral at this level, with a wide range of preservations. Formerly Lonsdaleia which is now restricted to branching versions.
- 3 comments
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- 1
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- actinocyathus
- alston formation
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A rare genus from this bed, one previous record seen from Cumbria. It is common earlier in the Mississippian of the region. The voids are filled with transparent calcite. This genus has a lonsdaleoid outer dissepimentarium (looking like large bubbles). As is most commonly the case, it was largely removed prior to fossilisation, leaving a trace on one side (see photo 4). The contorted axial region is typical.
- 5 comments
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- 1
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- axophyllum
- carboniferous
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