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Showing results for tags 'mississippian period'.
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Crinoid Spine in matrix - with Archimedes Bryzoan fronds on background matrix Chesterian Zone of the Bangor Limestone Formation in northern Alabama Mississippian Period ca 325,000,000 yrs old A matrix with a Crinoid Spine. Crinoids are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). The name comes from the Greek word krinon, "a lily", and eidos, "form". They live in both shallow water and in depths as great as 9,000 meters (30,000 ft). Those crinoids which in their adult form are attached to the sea bottom by a stalk are commonly called sea lilies. The unstalked forms are called feather stars or comatulids. Crinoids are characterised by a mouth on the top surface that is surrounded by feeding arms. They have a U-shaped gut, and their anus is located next to the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, most crinoids have many more than five arms. Crinoids usually have a stem used to attach themselves to a substrate, but many live attached only as juveniles and become free-swimming as adults. There are only about 600 extant crinoid species, but they were much more abundant and diverse in the past. Some thick limestone beds dating to the mid- to late-Paleozoic are almost entirely made up of disarticulated crinoid fragments. Kingdom: Animalia Phylum: Echinodermata Class: Cridoidea
sLast weekend I took a four day trip to Kentucky to see family; parents, sister, brother-in-law, and nephew. While there arranged to get together with Herb from the Forum to collect Mississippian Age fossils which I hadn't done before. There are no fossiliferous Mississippian Age deposits in New York and the nearest are in Western Pennsylvania hours away, so this looked like a good opportunity to add some marine fossils from that age to my collection. Fortunately where my family lives is in an area of marine Mississippian deposits. On the way to our rendezvous with Herb in E-Town (Elizabethtown) my nephew and I stopped at a road cut in Leitchfield that he knew about and had seen other collectors collecting at. Fossils were eroding out of the hillside by the score and could be picked up right off the ground free of the matrix. Collected a number crinoid stems, bryozoans, and small brachiopods. After an hour, we continued on to our meet up with Herb. My nephew had already met Herb at a collecting site. We continued on to another road cut collecting site about forty minutes away. Again, fossils were eroding out of the hillside and could be picked right up free of the matrix. Prior to this I had no blastoids in my collection but in just an hour and a half I'd collected fifteen plus more brachiopods, crinoid stems, and some more bryozoan specimens. We then returned to the first place in Leitchfield where my nephew and I visited earlier. Found more specimens including a number of crinoid calyxes, a couple blastoids, and a few more brachiopods and bryozoans. I'll have to study to learn the IDs of these specimens. All in all a great day and Herb was wonderful to collect with and very generous and knowledgeable besides. Hope we get to do this again next year. Oh, and by the way, the family visit went well too.