Echinoderm ichnology: bioturbation, bioerosion and related processes

Abstract

Abstract.-Among invertebrates and both in modern and ancient marine environments, certain echinoderms have been and are some of the most active and widespread bioturbators and bioeroders. Bioturbation and/or bioerosion of regular and irregular echinoids, starfish, brittle stars, sea cucumbers and crinoids are known from modern settings, and some of the resulting traces have their counterparts in the fossil record. By contrast, surficial trails or trackways produced by other modern echinoderms, e.g., sand dollars, exhibit a lower preservation rate and have not yet been identified in the fossil record. In addition, the unique features of the echinoderm skeleton (e.g., composition, rapid growth, multi-element architecture, etc.) may promote the production of related traces produced by the reutilization of echinoderm ossicles (e.g., burrow lining), predation (e.g., borings), or parasitism (e.g., swellings or cysts). Finally, the skeletal robustness of some echinoids may promote their post mortum use as benthic islands for the settlement of hard-substrate dwellers.

Geoconservation in the Cabeço da Ladeira Paleontological Site (Serras de Aire e Candeeiros Nature Park, Portugal): Exquisite Preservation of Animals and Their Behavioral Activities in a Middle Jurassic Carbonate Tidal Flat

“…The fact that the cidaroid presumably intentionally walked together with Krinodromos bentou produced by a stalked isocrinid-in the same bed (Bed 2) and a few meters distant from one anotheris evidence for predator and prey coexistence. The comprehensive work on echinoderm ichnology of Belaústegui et al [17] also shows that the cidaroid trackway from Cabeço da Ladeira is the first echinoderm locomotion behavior described from the fossil record. Of remarkable relevance is the association of trace fossils with their echinoderm makers.…”

“…The presence of articulated individuals associated directly to trace fossils, including the first record of a fossil trail associated to a stalked crinoid [6,17], and trace fossils never described before in the evolutionary stem of clades such as the crabs and the batoids (Figure 4), makes the Cabeço da Ladeira site a unique lagerstä tte for the Middle Jurassic [4,6,7].…”

The Taphonomy of Echinoids

“…There are a host of parasites that also affect echinoids (Jangoux 1984), some of them leaving distinct traces on the skeleton. Various traces attributed to parasites include galls in tests and spines (see the compilations in Donovan 2015, Belaústegui et al 2017. Malformations include pinching of ambulacral pore rows present in fossils (e.g., Tavani 1935, Roman 1952, 1953, Marcopoulos-Diacantoni 1970, Abdelhamid 1999, Zamora et al 2008) as well as pits and holes in the tests (Grun et al 2020).…”

Bioerosional structures from the Late Pleistocene coral reef, Red Sea coast, northwest Saudi Arabia

“…The study of bioerosion has revealed significant information about the ecological interactions between organisms and strata for the geological past history. Therefore, trace fossils also present useful data for paleoecological analyses (e.g., Belaústegui et al, 2017). Bioeroders attack living and dead shell material alike, although some of them are highly selective .…”