Well.it looks like the taxonomists aren t really sure where the zoophycos belongs. It seems that it has been classified as a ichnogenus (a fossil produced by an animal or plant)--> Zoophycos is an ichnogenus thought to be produced by feeding worms. An ichnotaxon (aka: trace fossil) is defined by the International Code of Zoological Nomenclature as "a taxon based on the fossilized work of an organism". Ichnotaxa are names used to identify and distinguish morphologically distinctive trace fossils. They are assigned genus and species ranks by ichnologists, much like organisms in Linnaean taxonomy. These are known as ichnogenera and ichnospecies, respectively. Ichnotaxa include trace fossils such as burrows, borings and etchings, tracks and trackways, coprolites, gastroliths, regurgitaliths, nests, leaf mines, and bite and gnaw structures, as well as secretions modified by organismal activity, such as cocoons, pupal cases, spider webs, embedment structures and plant galls. http://en.wikipedia.org/wiki/Ichnogenus I think you are going to have trouble with the taxonomy. From this website: http://www.peripatus.gen.nz/paleontology/defTraFos.html Ichnotaxa are given Linnaean-style (binomial) taxonomic names, just as if they were actual organisms. The assignment of names to actual animals (or parts of animals) is usually dictated by the rules set out in the ICZN (International Code of Zoological Nomenclature; there is also an ICBN for botanical names). However, trace fossils are not actual organisms or parts of organisms, so they cannot be given Linnaean names recognised by the International Committee on Zoological Nomenclature. Very occasionally, it may be possible (e.g. by finding a fossilised body fossil at the end of a trail or burrow) to learn which particular organism makes a particular trace fossil – assuming the trace is distinctive enough to be sure that apparently identical versions are not created by several different organisms – but mostly the "owner" is unknown. Part of the confusion regarding this nomenclature arises from the common lack of connection between the trace fossil name and the name of its original trace maker. Some trace fossils were made by unknown, extinct, or poorly preserved organisms, hence the ichnogenus name can not be expected to reflect a specific trace maker. As far as the crinoid stem goes.I could only find the present day crinoid taxonomy: Phylum Echinodermata (echinoderms) Class Crinoidea (feather stars and sea lillies) Subclass Articulata Order Bourgueticrinida Order Comatulida http://animaldiversity.ummz.umich.edu/site/accounts/classification/Crinoidea.html#Crinoidea Here is some information on the fossilized crinoid species: Some fossil crinoids, such as Pentacrinites, seem to have lived attached to floating driftwood and complete colonies are often found. Sometimes this driftwood would become waterlogged and sink to the bottom, taking the attached crinoids with it. The stem of Pentacrinites can be several metres long. Modern relatives of Pentacrinites live in gentle currents attached to rocks by the end of their stem, which is fairly short. The largest fossil crinoid on record had a stem 40 m (130 ft) in length. In 2006, geologists isolated complex organic molecules from 350-million-year-old fossils of crinoids -- the oldest such molecules yet found. Christina O Malley, a doctoral student in earth sciences at Ohio State University, found orange and yellow organic molecules inside the fossilized remains of several species of crinoids dating back to the Mississippian period. http://en.wikipedia.org/wiki/Crinoid#Fossils_of_passing_interest ----------------------------------------------------------- This website: http://www.kgs.ku.edu/Extension/fossils/crinoid.html claims that the taxonomic classification of crinoids is: Kingdom Animalia Phylum Echinodermata Subphylum Crinozoa Class Crinoidea. That last website is a GREAT resource on the crinoid fossils.