Muricid boreholes in Pleistocene acorn barnacles from the Beagle Channel: trophic interactions during the Last Interglacial in southern South America

Abstract

Gordillo, S., 2013. Muricid boreholes in Pleistocene acorn barnacles from the Beagle Channel: trophic interactions during the Last Interglacial in southern South America. Alcheringa 37, 1–8. ISSN 0311-5518.

Acorn barnacles with boreholes were recovered from a Pleistocene marine deposit on Navarino Island, on the southern coast of the Beagle Channel. Balanomorph shells were identified as Balanus laevis (Bruguière, 1789), and a few bear small round holes located generally on the middle or apical part of the parietal plates, thus suggesting that they represent the work of small muricid predators. If so, this study is the first record of drilling predation on fossil barnacles reported in southern South America.

[Sandra Gordillo [[email protected]], Centro de Investigaciones en Ciencias de la Tierra, Consejo Nacional de Investigaciones Científicas y Técnicas (CICTERRA, CONICET-UNC); Centro de Investigaciones Paleobiológicas (CIPAL), Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Vélez Sársfield 1611 X5016GCA Córdoba, Argentina. Received 8.1.2013; revised 26.3.2013; accepted 2.4.2013

Beagle Channel更新世橡子藤壶上的muricid钻孔: 南美南部最近间冰期期间的热带互动

带钻孔的橡子藤壶发现于Beagle Channel南岸的Navarino 岛上的更新世海相沉积物中。 Balanomorph壳 被鉴定为Balanus laevis (Bruguieri, 1789), 其中一些带有小圆孔, 通常位于顶板中部或顶尖部, 这些都表明钻孔代表着小型muricid捕食动物所为。如果是这样, 本项研究是发现于南美南部的化石藤壶上钻孔捕食作用的首次记录。

Key words:

• Southern South America
• Pleistocene
• barnacles
• muricid boreholes
• predation

Acknowledgements

I wish to thank F. Pitombo (Universidade Federal Fluminense, Brazil) and A. Rico (Universidad Nacional de la Patagonia, Argentina) for providing information on living barnacles, and A. Beu (GNS Science, New Zealand), M. Kowalewski (Department of Geosciences, Virginia) and S. McLoughlin (Editor) for comments and constructive reviews that improved this manuscript. This study was supported by a grant from CONICET (PIP 09-260) and this paper is also a contribution to project INACH G05-11.