The "Curse of Rafinesquina:" Negative Taphonomic Feedback Exerted by Strophomenid Shells on Storm-Buried Lingulids in the Cincinnatian Series (Katian, Ordovician) of Ohio

A new phosphatized ophiuroid from the lower Triassic of Nevada and its position in the evolutionary history of the Ophiuroidea (Echinodermata)

“…Thanks to phosphatization, the ophiuroid ossicles were left unscathed by the dissolution of the hard, fossiliferous limestone. There has been some debate surrounding the mechanisms behind phosphatization during this time period, in particular phosphogenesis driven by high-energy mixing events (Freeman et al 2013;Milam et al 2017) versus phosphatization occurring in beds with low sedimentation rates and/or sedimentary hiatuses (Freeman et al 2019,). Maxwell et al (2020) observed a link between small shell size and phosphatization, and suggest phosphatization resulted from the combination of warm pore water with low levels of oxygen and the small particle size of the ophiuroid fragments.…”

Sclerobiosis: A Term for Colonization of Marine Hard Substrates

“…Both neontologists and paleontologists have used the terms epibiont and epibiosis to describe the colonization of dead organic and inorganic substrates (see Taylor & Wilson, 2003 and references cited therein;Freeman et al, 2013;Schneider, 2013), as well as to refer to vagile organisms associated with a living organism (e.g., Ayres-Peres & Mantelatto, 2010;Fuller, et al 2010;Smyth & Roberts, 2010;Gordillo & Archuby, 2014). Some authors use the term epibiont to indicate invertebrates that live on rocks, pebbles or boulders (Plint et al, 2006;Chumakov et al, 2013;Powell et al, 2019).…”

Time-richness and phosphatic microsteinkern accumulation in the Cincinnatian (Katian) Ordovician, USA: An example of polycyclic phosphogenic condensation

“…Some delicate multi-element skeletons are perfectly preserved and were apparently buried alive, others are merely disarticulated, while others are represented by comminuted fragments in the same bed. Third, thicker and more amalgamated beds tend to show more evidence of taphonomic feedback (Kidwell and Jablonski, 1983;Freeman et al 2013) with more frequent encrustation, and with earlier ecological stages being more poorly preserved.…”

“…The serendipitous discovery of very low concentrations of microsteinkerns during a shell bed taphonomic study (Freeman et al, 2013) led to the hypothesis that phosphogenesis was a slow geochemical process operating under normal marine conditions (Dattilo et al, 2016). The PPC process (Freeman et al, this volume) explains how this slow process leads to the accumulation of phosphatic microsteinkerns as the shell bed develops, through iterative precipitation and reworking events, resulting in strong correlations between textural maturity and phosphatic microsteinkern concentration.…”