Parasitic gastropod bioerosion trace fossil on Cenomanian oysters from Le Mans, France and its ichnologic and taphonomic context Author Breton, Gérard Author Wisshak, Max Author Néraudeau, Didier Author Morel, Nicolas text Acta Palaeontologica Polonica 2017 2016-11-16 62 1 45 57 http://dx.doi.org/10.4202/app.00304.2016 journal article 10.4202/app.00304.2016 1732-2421 10626457 6F2915EB-E224-458D-AEA7-15F7CEFA2246 Ichnogenus Loxolenichnus Breton and Wisshak nov. Type ichnospecies : Loxolenichnus stellatocinctus Breton and Wisshak isp. nov. ; see below. Included ichnospecies : The type ichnospecies, Loxolenichnus halo ( Neumann and Wisshak, 2009 ) comb. nov. , and Loxolenichnus taddei ( Ruggiero and Raia, 2014 ) comb. nov. Figs. 5 , 6 . Etymology : Contraction of the ancient Greek words loxós (λοξός), oblique, and solen (σωλήν), canal, pipe; allusion to the central oblique penetration hole in the holotype of the type ichnospecies. Ichnus is a common ending for trace fossils names, referring to ancient Greek ichnos , track. Gender masculine. Diagnosis .—A single or rarely several cylindrical holes, completely cutting through calcareous shelly substrates, surrounded by a circular to elliptical depression with concentrical grooves. Remarks .—The ichnogenus Oichnus Bromley, 1981 , except the ichnospecies Oichnus halo Neumann and Wisshak, 2009 and Oichnus taddei Ruggiero and Raia, 2014 which are herein transferred to Loxolenichnus , lack the attachment scar and peripheral groove. The ichnogenera Anellusichnus Santos, Mayoral, and Muñiz, 2005 , Lacrimichnus Santos, Mayoral, and Muñiz, 2003 and Centrichnus Bromley and Martinell, 1991 in turn are pure attachment scars and lack the penetration hole(s) passing through the substrate. Kardopomorphos , with its sole ichnospecies Kardopomorphos polydioryx Beuck, López Correa, and Freiwald, 2008 is a rounded or spiral-shaped pit, from which many whip-shaped, branched canals including sometimes one or few central larger canals penetrate deeply in the substrate. By including two former Oichnus ichnospecies, Oichnus is now constrained to pure predation traces (Praedichnia). The new ichnogenus, in contrast, comprises three ichnospecies that are all combinations of complete penetrations (parasitic in nature and thus unlike Praedichnia sensu stricto) and an attachment scar (Fixichnia), and this combination of two different modes of bioerosion is characteristic of the new ichnogenus.