Original paper
Trace fossils on a trace fossil: a vertebrate-bitten vertebrate coprolite from the Miocene of Italy
Collareta, Alberto; Gemelli, Maurizio; Varola, Angelo; Bianucci, Giovanni
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 293 Heft 2 (2019), p. 117 - 126
68 references
published: Aug 27, 2019
manuscript accepted: May 27, 2019
manuscript received: Apr 17, 2019
ArtNo. ESP155029302000, Price: 29.00 €
Abstract
Despite their long history of discoveries and research, of all the vertebrate coprolites currently known worldwide, only a very few have been explicitly recognised as exhibiting bite marks by other vertebrates. These rare specimens represent “compound ichnofossils”, i.e., trace fossils (the lithified faeces) on which other trace fossils (the tooth incisions) are present. Here we report on an unusual large-sized coprolite from the Miocene “Pietra leccese” formation of southern Italy that displays several superficial bite marks. This specimen is described, figured, and chemically characterised by means of hand-held energy dispersive X‑ray fluorescence – the first application of this method to the analysis of a vertebrate coprolite. Based on its size, morphology, structure, and major-element composition, the Pietra leccese coprolite is here identified as the fossilised excreta of a large carnivorous vertebrate, possibly a shark, whereas the tooth incisions are attributed to the biting action of indeterminate fish, likely including both bony and cartilaginous fish. Biting seemingly occurred prior to the eventual deposition of the scat at the seafloor (i.e., when it was still in the water column) and probably reflects unintentional snagging or aborted exploratory coprophagy aimed at testing the palatability of the faeces. In conclusion, the highly idiosyncratic specimen described in this paper represents a significant addition to the overly scanty record of vertebrate-bitten vertebrate coprolites and provides an unusual window on the ecological interactions between marine vertebrates in the Miocene central Mediterranean ecosystems witnessed by the remarkable fossil assemblage of the Pietra leccese.
Keywords
Bite marks • bromalite • compound ichnofossil • Digestichnia • HHXRF • Mediterranean • palaeoecology • Pietra leccese • vertebrate ichnology • shark