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A lovely 18" belemnite slab I've bought for my birthday (birthday belemnites are a bit of a tradition!). From the Jurassic Posidonienschiefer (Toarcian, Upper Lias) of Holzmaden - a very interesting and unusual selection of mostly the same species, one with a nice epirostrum. Not quite sure of the actual species, but it's close to Acrocoelites subtenuis and A. gracilis - neither of which usually have epirostra (the squashed bit at the tip of photo 2). It also contains a couple of bonus teeth including a Hybodus type which Sebastian @belemniten tells me is a rarity there. Apart from the fact it's a great display piece, the main reason I bought it is its faunal similarity to the basal beds of the Alum Shales around Whitby in Yorkshire, known as the "Hard Shales" (Toarcian, Bifrons Zone). There, you get accumulations of Acrocoelites subtenuis at the same sort of density - possibly conspecific with these, but never showing an epirostrum. One possible reason for this is that the epirostrum is a sexual dimorphism, connected with breeding grounds, so they only occur in specific areas at any given time. Or it may just be a different species... form with short epirostrum: orthorostrum:
TqB posted a topic in Questions & AnswersI've just purchased a fine slab of belemnites from Holzmaden and the stratigraphy is given as Posidonienschifer, Lias epsilon II-102. I know that epsilon is Lower Toarcian but please could anyone enlighten me about the II-102? I particularly want to correlate this accurately with Yorkshire, if possible! @belemniten ? EDIT: I've just checked the seller's other material and one that I'd expect to be from the same beds is given as "II-12" - so @oilshale is almost certainly right with his answer below, and it seems to be near the base of the Bifrons Zone.
TqB posted a topic in Member CollectionsExtremely rare, I never thought I'd get the chance to acquire one of these so I was very pleased when one came up for sale. Chitinobelus acifer Fischer 1981, a belemnite (or possibly belemnotheutid) whose rostrum was originally composed of aragonite with organic material. As a result, it's preserved as a compressed organic film with the aragonite lost to diagenesis. Belemnites are nearly always mostly calcite (largely thought to be primary) and preserve 3D in all sorts of rock. There is argument (quite complex) over whether this is an unusual aragonitic belemnite or something a bit different. There are prominent striations which are similar to those in the "normal" belemnite, Salpingoteuthis. From the Jurassic, Lower Toarcian Posidonienschiefer of Zell (not far from Holzmaden, Germany). As far as I know, this is the only locality it's been found. Phragmocone chambers just visible.