Unravelling the nature of Waiparaconus, a pennatulacean (Cnidaria: Octocorallia) from the Late Mesozoic–Early Cainozoic of the Southern Hemisphere

Abstract

Enigmatic calcareous conical fossils have been known from marine Paleocene-Eocene sequences of New Zealand since the early 1870s. More recently, similar fossils have been recorded from both Late Cretaceous marine sequences of Western Australia, New Caledonia and Antarctica, and possibly from the Eocene of South America. The present paper extends the record to the late Cretaceous of New Caledonia. These remains are unlike any living taxa, and have been variously interpreted as molluscs (rudistid bivalves), cirripedes (stalked barnacles), annelids and inorganic structures. Assignation to the Cirripedia has been refuted by Buckeridge (1983, 1993), who proposed that the material would be better placed within the Cnidaria. We investigate this hypothesis in light of the New Caledonian material and by comparison with living gorgonians and pennatulaceans, and demonstrate that Waiparaconus is best placed within the Pennatulacea. Waiparaconus zelandicus varies in form somewhat, with 3 morphotypes defined and reinforced by geography. Comment is provided on the imperative to fit organic remains into known groups, with reflection on what may happen if taxa are left in insertae sedis.

Paleontology and evolution–part I

“…Intriguing is the target of the paper authored by Buckeridge et al (2014) which analyze some enigmatic calcareous conical fossils with no living equivalents, ascribed to the genus Waiparaconus. The problematic remains were first recorded from marine Paleocene-Eocene sequences of New Zealand in the early 1870s and then interpreted as cirripedes, anellids, rudists, or even inorganic structures, reflecting the difficulty to find morphologic traits of undisputable taxonomic significance.…”

“…Such an example faces us with the problem of forcing problematic fossil remains into the pigeonholes of established classifications or rather accommodating them in a not better defined insertae sedis category. Buckeridge et al (2014) chose the first option and finally classified Waiparaconus as a pennatulacean. Though based on sound data, such a decision might anyhow be questionable.…”

“…In so doing, Integrative Zoology, a journal especially devoted to delve into neontological themes, dedicates this special issue to evolutionary aspects in a deep time perspective and related paleontological issues such as paleobiogeography and paleoecology as well as taxonomic principles. Intriguing is the target of the pa-per authored by Buckeridge et al (2014) which analyze some enigmatic calcareous conical fossils with no living equivalents, ascribed to the genus Waiparaconus. The problematic remains were first recorded from marine Paleocene-Eocene sequences of New Zealand in the early 1870s and then interpreted as cirripedes, anellids, rudists, or even inorganic structures, reflecting the difficulty to find morphologic traits of undisputable taxonomic significance.…”