Article: A post-script to the enigmatic Protonympha (Devonian; New York): is it an arm of the echinoderms?

A unique specimen of the supposed arm of the Middle Devonian (Givetian) starfish Foliaster transversus Blake, 1994[Journal of Palaeontology, 68, 123-134] is shown to be closely comparable to the enigmatic organism Protonympha salicifolia, also of Devonian age, albeit slightly younger (Frasnian), and also from New York State. Similarities to starfish, or any other echinoderm, appear to be superficial. Differences from the type species of Protonympha are minor, but include the detailed structure of the transverse segments. For this reason a specific distinction is retained, and the taxon Protonympha transversa (Blake, 1994) now proposed. Enigmatic fossils such as Protonympha raised related questions of evolutionary affinity and the problems of pattern recognition. These questions may also touch on the interpretation of organic structures, such as might be returned from Mars (or further afield).