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Megaonychites, form genus for the giant hooks that some belemnites have been shown to carry as a pair. By analogy with modern coleoids, they were probably carried by the males and used as mating claspers. This is a fairly large one at 3.4cm (the range is 0.5cm to about 4cm). It most likely belonged to a large Acrocoelites trisulculosus, by far the most common belemnite in these beds. Very rare in the UK but more frequent in the equivalent Holzmaden Posidonienschiefer. I've only seen one other from here - a partial - and that was mine until I gave it away thinking at the time it was a fish bone. (It was a long time ago... ). A recent acquisition from the usual auction site. (Found by a knowledgeable friend so the stratigraphy is good.) Mulgrave Formation ("Jet Rock"), Toarcian Stage, Lower Jurassic, near Whitby, Yorkshire, UK.
Please could anyone suggest what this is? I'm assuming fish, with little (less than 1mm) white spherules that might be teeth or denticles. From the Jet Rock (Mulgrave Shale Member) - a Lower Jurassic, Toarcian shale at least partly deposited in anoxic waters. Near Whitby, Yorkshire, UK. (Acquired in an auction as an extra with another fossil that I really wanted so I'm just curious really, I know little about fish!)
TqB posted a topic in Member CollectionsAt over 4" across, this is the last few chambers of by far the largest diameter belemnite phragmocone I've ever seen. (If anyone has one from a Megateuthis, I'd love to see it! - they don't seem ever to be preserved.) Given to me by a friend, it is in a nodule from the Jet Rock (Upper Lias, Lower Jurassic) of Port Mulgrave, north Yorkshire coast. It must have belonged to an exceptionally large Acrocoelites trisulculosus which is probably the only belemnite to occur in this bed. It's a large species anyway - typical rostra of it are 5 - 7" long but about 9" has very rarely been recorded so a bit longer may be possible. Photo 6: Not having such a large Acrocoelites in my collection, I've done a conservative mock-up of it with a smallish (9") Megateuthis and another piece of phragmocone which is my second largest... A total length of 20 - 24" seems about right. Photo 7: For comparison , I have a complete but crushed example of A. trisulculosus about 12" long, the rostrum being 6.5". 1) 2) 3) 4) 5) 6) This should probably be stretched more... 7) A normal size Acrocoelites trisulculosus with crushed phragmocone (the strange ridged structure on top of it is a crushed on-edge Harpoceras shell mouth)