Deep-water cirripedes colonizing dead shells of the cephalopod .i.Nautilus macromphalus./i. from New Caledonian waters

0518678 - GLÚ 2020 RIV AU eng J - Journal Article
Buckeridge, J. - Kočí, T. - Schlögl, J. - Tomašových, A. - Kočová Veselská, Martina
Deep-water cirripedes colonizing dead shells of the cephalopod Nautilus macromphalus from New Caledonian waters.
Integrative Zoology. Roč. 14, č. 6 (2019), s. 561-575. ISSN 1749-4877. E-ISSN 1749-4869
Institutional support: RVO:67985831
Keywords : i.iAnellusichnus ellipticus isp. nov * cirripedes * epibionts * Hexelasma velutinum * Metaverruca recta
OECD category: Paleontology
Impact factor: 2.514, year: 2019
Method of publishing: Open access
https://onlinelibrary.wiley.com/doi/epdf/10.1111/1749-4877.12389

Fossil cephalopods are frequently encrusted by epibionts, however, determining whether encrustation occurred prior to or post-mortem to the host, and whether the final environment of deposition corresponds to the habitat of encrustation is complex. The present paper describes cirripede epibionts, their calcareous bases and their attachment scars on 6 post-mortem shells of Nautilus macromphalus, collected from deep water off New Caledonia. The cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph barnacles. Live cirripedes included a Metaverruca recta , with articulated opercular plates and organic tissue (on a shell that had been exposed on the sea floor for at least 150 years), and specimens of Hexelasma velutinum, one of which was partly attached to an internal surface of a shell. The disposition of verrucomorphs indicates that most Nautilus shells were colonized post-mortem rather than during a floating stage. However, as cirripedes are known to have colonized living Nautilus, some Hexelasma, preserved only as calcareous eroded bases, may represent specimens that settled on a living Nautilus. The degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of Nautilus shells, with deeper and discolored traces preserved on old and degraded shells. Traces made by verrucomorphs described here are ellipsoidal and a new ichnotaxon, Anellusichnus ellipticus, is proposed to accommodate them. Importantly, verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars, and, thus, will be difficult to detect in the fossil record.
Permanent Link: http://hdl.handle.net/11104/0305188