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Conotubus--An Endearing Ediacaran Critter: My Latest New Favorite Fossil
Virgilian posted a topic in General Fossil Discussion
Conotubus--my new latest favorite fossil. It's an Ediacaran (latest Neoproterozoic--AKA, Precambrian) tubular critter of unestablished zoological affinity (educated guesses include an annelid--specifically some kind of tube worm--or possibly a sea anemone-like animal). And it's been recovered from only two localities on Earth: southern Shaanxi Province, South China; and at one lone site in Nevada. Conotubus shows superficial similarity to the well known Ediacaran tube-type specimen Cloudina, but lacks a mineralized skeleton. Conotubus apparently secreted a tubular home enclosure composed of chitinous material. Image from HERE. Above, two views of the same pyritized (replaced at least partially by pyrite--an iron disulfide, of course, commonly called "fool's gold") Conotubus from the upper Precambrian Esmeralda Member of the upper Precambrian-lower Cambrian Deep Spring Formation, Nevada, where Conotubus occurs several feet below the first appearance of the ichnofossil Trepichnus pedum, which presently helps define (along with geochemical evidence-- a sudden, dramatic negative excursion of a specific carbon isotope) the worldwide base of the Cambrian Period, the transition from Ediacaran times to the earliest moments of the Paleozoic Era. Photograph is a Google Image grab, by the way. Image from HERE. Examples of pyritized Conotubus hemiannulatus from the Ediacaran, late Neoproterozoic Gaojiashan Lagerstätte of southern Shaanxi Province, South China. Photograph is a Google Image grab, by the way.