Description: The ongoing technical revolution in non-destructive 3D-visualisation via micro-computed tomography (micro-CT) finds a valuable application in the studies of bioerosion trace fossils the three-dimensional architecture of which lies hidden within hard substrates. This technique, in concert with advanced segmentation algorithms, allows a detailed visualisation and targeted morphometric analyses even of those bioerosion traces that are otherwise inaccessible to the widely applied cast-embedding technique, because they are either filled with lithified sediment or cement, or are preserved in inherently insoluble or silicified host substrates, or because they are established type material and should not be altered. In the present contribution selected examples of such cases are illustrated by reference to bioerosion trace fossils preserved in Late Cretaceous belemnite guards from the European Chalk Province. These case studies comprise an analysis of a diverse ichno-assemblage found associated with the lectotype of the microboring Dendrina dendrina Morris, 1851 in a belemnite from the upper Campanian to lower Maastrichtian chalk of Norfolk, England, and the description of two new bioerosion trace fossils with type specimens found in belemnite guards from the lower Campanian limestones of Höver, Germany. The latter are Lapispecus hastatus isp. n., a tubular and occasionally branched macroboring for which a sipunculan or a phoronid trace maker are discussed, and Entobia colaria isp. n., a camerate network formed by an excavating sponge that eroded diagnostic grated apertures at the locations of the presumed inhalant papillae or exhaling pores, adding to or replacing filtering devices that are otherwise made of tissue and spicules. As an added value to the non-destructive visualisation procedure, the processed X-ray micro-CT scans of the studied type material provide 3D-models that may now serve as digitypes that can be studied as digital facsimile without the necessity of consulting the actual type specimens.

Description: Mineral geochemical data of drill core serpentinites from the Mariana serpentinite mud volcanoes (IODP Exp. 366), including major element and fluid-mobile element (Li, B, Rb, Sr, Cs, Ba) compositions of olivine, spinel, clinopyroxene, orthopyroxene, serpentine, and brucite as determined by electron microprobe and laser ablation-ICP-MS.