Cothurnocystis Ordovician Carpoid Fossil

This is an excellent example of the carpoid Cothurnocystis elizae, seen as a part and counterpart specimen. The carpoids are one of the most contentious groups of fossil organisms known. While they have been studied for over 150 years, their unique character combinations have caused a number of disputes over both their paleobiology and relationships. While some place them in the Echinodermata, their lack of pentaradial symmetry calls that placement into question. Additionally many carpoids are thought to have possessed gill slits (this one has been so interpreted), a feature characteristic of chordates and hemichaordates. Many possess one or two “appendages” which have been interpreted variously as feeding tubes, tails with notocords and muscular feet. The carpoid body was supported by a skeleton of calcitic plates like those found in modern Echinoderms. Some believe that a carpoid may have been the common ancestor between Echinoderms and Vertebrates. It is important to note the carpoids differ from ALL other animals, living and extinct, in that many are completely asymmetrical. With so much debate over assignment of the appendages to specific functions, how can one come to a conclusion about their assignment in the Tree of Life? This one is rarely offered for sale.