1 10 1 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/096e8ba3d85cb6710d025c8a47c6b650.png dafdee752e982fb456d58759fe553388 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/9210643b87c961dd79670feb9079babe.png 8753d0aed58123df89e9df5181ddaaa9 Physical Object An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource <h2><strong>TF0903<br /></strong></h2> <h2>Irregular echinoid</h2> Subject The topic of the resource <h3>Location</h3> <div class="element-text"><span>Upper Chalk, Weston Colville, Cambridgeshire</span></div> Description An account of the resource <div class="element"> <h3>Species</h3> <div class="element-text">Praecursor</div> </div> <div class="element"> <h3>Stratigraphic Range</h3> <div class="element-text">Cretaceous</div> </div> <div class="element"> <h3>Taxonomy</h3> <div class="element-text">Phylum: Echinodermata<br />Class: Echinoidea<br />Subclass: Irregularia<br />Order: Spatangoida<br />Genus: Micraster<br /><br /></div> </div> <div class="element"> <h3>Distinctive Features</h3> <div class="element-text">Bilateral symmetry<br />Five radial ambulacra<br />Peristome (opening for mouth) and periproct (opening for anus) migrated<br />Spine attachment scars</div> </div> <div class="element"> <h3>Preservation</h3> <div class="element-text">Sediment infil<br />Shell mineral replacement<br />Disarticulation of spines</div> </div> <div class="element"> <h3>Advanced notes</h3> <div class="element-text">Note the streamlined shape for burrowing through the sediment, and how the ambulacra, which bear the tube feet, do not continue onto the underside of the animal where the mouth is.<br />This is because the tube feet are used for respiration but not for movement, for which small spines are used.</div> </div> bilateral burrow movement pentaradial symmetry