Pickerill, R.K. 2006: Ichnologic picture. Ichnos, vol. 13,#2, p. 95.
Coprolites are pieces of (extruded) fecal matter that became fossilised. Me and my student fellow Moritz investigated more than 100 specimens in order to learn something about the palaeoecology of Permian fresh water deposits of the Planitz Formation (Zwickau, Saxony).
Although being a very interesting project, this study revealed nothing in particular. First, different sizes of coprolites didn't show any significant trend or a favoured lenght/width ratio. The problem is that a single organism may produce fecal matter with various forms and, vice versa, numerous organisms may produce the same general form and size-range (Aldridge et al. 2006, Baxendale 1979). Accordingly, it is hard to tell whether these coprolites were produced by one single species or if they are the result of teamwork of a multitude of phyla.
The majority of the investigated coprolite material was anisopalar-coiled and resembled (not as delicious though) wraps or crêpes. According to Jain (1983) such a morphology is expected being produced by organisms possessing a scroll valve. None of the predators that are recorded by body fossils in these lake sediments match this criterion. Xenacanth Sharks which are accused by Kogan (2006) to have left this mess are not in charge anymore because they had a spiral valve which would rather produce a coiled fecal ribbon rather than such 'coprocrêpes'. All what we can say with confidence is that the producer was a fish feeding predator preferring actinopterygian fish like Paramblypertus, Amblypterus and Igornichtys (Kogan, 2006).
Aldridge, R., Gabbott, S., Siveter, L. and Theron, J.: 2006, Bromalites from the Soom Shale Lagerstätte (Upper Ordovician) of South Africa: palaeoecological and palaeobiological implications, Palaeontology 49(4), 857–871.
Baxendale, R.: 1979, Plant-bearing coprolites from North American Pennsylvanian coal balls, Palaeontology 22(3), 537–548.
Jain, S.: 1983, Spirally coiled coprolites from he Upper Triassic Maleri Formation, India, Palaeontology 26(4), 813–829.
Kogan, I.: 2006, Paläontologie, Sedimentologie und Paläoökologie des Unterrotliegend Planitz-Sees im Erzgebirge-Becken, unpublished Master thesis, TU Bergakademie Freiberg.