An exceptionally preserved parasitic arthropod, Heymonsicambria taylori n.sp. (Arthropoda incertae sedis: Pentastomida), from Cambrian – Ordovician boundary beds of Newfoundland, Canada

Abstract

A three-dimensionally and completely preserved phosphatized microfossil has been found in Cambrian–Ordovician boundary bed limestones of the Green Point Formation at Green Point, western Newfoundland, Canada. It represents a new form of larvae, previously described by D. Walossek and K.J. Müller from Upper Cambrian anthraconitic limestones ("Orsten"). These authors identified the fossils as instars of marine stem-group representatives of the "tongue worms," Pentastomida. Pentastomida are parasites that today infest various land tetrapods and are presumed to represent one of the closest extant relatives of the Euarthropoda. This new fossil possesses remarkably well-preserved trunk limb vestigia and anal region. It is another example of exceptional three-dimensionally preserved, phosphatized fossils of the Orsten type that is no longer spatiotemporally restricted to the Upper Cambrian of Sweden.