Borings As Trace Fossils, and the Processes of Marine Bioerosion

Classical and new bioerosion trace fossils in Cretaceous belemnite guards characterised via micro-CT

“…In consideration of the tapering shape of the main tunnel, one can argue that it is unlikely that the worm was able to move freely back and forth in its tunnel and may have rather tightly filled out the excavation on a permanent basis. This would agree with a sipunculan trace maker, whose trunk permanently fills out the better part of its excavation, held in place with its body wall musculature acting as a hydrostatic skeleton and a variety of hooks, spines, and papillae embedded in their leathery skin (Warme, 1975;Cutler, 1994). Only a highly flexible introvert was expandable and retractable (Cutler, 1994).…”

“…The ability of sipunculans to bioerode is well known; they may form a significant component of bioeroder communities (e.g. Bromley, 1970;Warme, 1975;Cutler, 1994;Hutchings and Peyrot-Clausade, 2002;Antonelli et al, 2015). Mechanical and chemical mechanisms of bioerosion, or a combination of these, have been advocated (for reviews, see Rice, 1969;Bromley, 1970;Williams and Margolis, 1974).…”

“…Alternatively, targeted chemical dissolution would need to be proposed to explain the formation of these asymmetrical features of Lapispecus, but given the limitations of the body fossil record and lack of deduced physiological knowledge on Cretaceous sipunculids, a more detailed identification seems unfeasible at this stage. A trace formation with the anterior introvert, such as proposed by Warme (1975) and others, would require repeated vacation of the boring and repositioning, which appears awkward and would have left the animal exposed to predators. In concord with Rice's (1969) analysis, this explanation is herein considered less likely.…”

Sponge bioerosion accelerated by ocean acidification across species and latitudes?

“…Degradation of calcareous materials by marine bioerosion is an important recycling process that acts at different scales and is performed by a wide spectrum of organisms employing different chemical and mechanical means in the process of attachment, grazing, or carbonate penetration (Warme 1975;Bromley 1992;Wisshak and Tapanila 2008;Tribollet et al 2011;. Considering the significant environmental changes of our century, recent research activities pay renewed attention to bioerosion and question how it may be influenced by global developments, and whether it may outweigh calcification processes (e.g.…”

Large dendrinids meet giant clam: the bioerosion trace fossil <i>Neodendrina carnelia</i> igen. et isp. n. in a <i>Tridacna</i> shell from Pleistocene–Holocene coral reef deposits, Red Sea, Egypt

“…Some representatives have been suspected or reported to etch carbonate substrates (e.g. Emery, 1963;Barnes and Topinka, 1969;Warme, 1975;Radwanski, 1977), but a detailed ichnological investigation and ichnotaxonomical treatment of these attachment etchings is pending. In general, both chlorophytes and rhodophytes may exhibit a dichotomous branching pattern of their endolithic or epilithic thalli (e.g.…”