Unraveling the origin of the Late Triassic multitaxic bone accumulation at Krasiejów (S Poland) by diagenetic analysis

Comment on “An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages” by Jerzy Dzik and Tomasz Sulej

“…The region was dominated by low-relief gilgai microrelief, characterized by alternating mounds and depressions, influenced by accidental heavy storm runoffs during wet seasons (Szulc 2005;compare Bilan 1975;Dzik et al 2000;Dzik and Sulej 2007;Bodzioch and Kowal-Linka 2012). Thus, its critical character includes the rapid lateral pinchout of the 0.5-m-thick bone bed in the Krasiejów clay pit (see also borehole data in Bilan 1975), in opposition to the predicted lateral continuity of the given horizon so typical of lacustrine basins (repeatedly asserted since Dzik et al 2000;Sulej 2007, 2016: 805-807).…”

“…But what, in this context, can be the meaning of the enigmatic (from a sedimentological viewpoint) phrase "periodic ponding at a lake shore"? The gray, fossil-bearing claystone layer is actually swamp sediment, underbedded by an impermeable vertisol and bounded by elevated ridges (and mostly graded upward into a reddish regolithic soil complex deposited during the next dry period; compare Szulc 2005;Bodzioch and Kowal-Linka 2012).…”

“…This has been proven on the grounds of the co-occurrence of bones that must have been primarily buried in different early diagenetic environments. This means that the remains forming the main time-averaged bone accumulation were redeposited from a large area and that the extensive Krasiejów depression, composed of complex evaporated post-flood ponds, was only the final place of their catastrophic burial (Bodzioch and Kowal-Linka 2012). The formal logical fallacy concerns the classical circulus vitiosus: the authors write "inhabitants of the Krasiejów lake", which implies that "the Krasiejów lake existed" (the first premise of unknown value, i.e., whether true or false) and "there were animals living in the Krasiejów lake" (the similar second premise); then, the authors describe adaptations to the aquatic lifestyle of "the inhabitants of the Krasiejów lake", which is offered as proof of the final conclusion "the Krasiejów lake existed" and, simultaneously, a false inference from the first premise.…”

“…The formal logical fallacy concerns the classical circulus vitiosus: the authors write "inhabitants of the Krasiejów lake", which implies that "the Krasiejów lake existed" (the first premise of unknown value, i.e., whether true or false) and "there were animals living in the Krasiejów lake" (the similar second premise); then, the authors describe adaptations to the aquatic lifestyle of "the inhabitants of the Krasiejów lake", which is offered as proof of the final conclusion "the Krasiejów lake existed" and, simultaneously, a false inference from the first premise. In this context, the principal disinformation resides in the statement that "According to Bodzioch and Kowal-Linka (2012) the early diagenetic history [of bones] was outside the aquatic environment and that they were subsequently transported to the lacustrine environment." The italicized (by us) phrase was never used by Bodzioch and Kowal-Linka (2012).…”

“…In this context, the principal disinformation resides in the statement that "According to Bodzioch and Kowal-Linka (2012) the early diagenetic history [of bones] was outside the aquatic environment and that they were subsequently transported to the lacustrine environment." The italicized (by us) phrase was never used by Bodzioch and Kowal-Linka (2012). And the last, but not least: in the description of the new species, its type horizon is defined merely as probably late Carnian "lacustrine bed", even though Dzik and Sulej (2016) cite the paper of Szulc et al (2015a) explaining the precise position of the Krasiejów bone-bearing level in the formal lithostratigraphic scheme of the Silesian Keuper (i.e., within the Grabowa Formation, an equivalent of the Weser and Arnstadt formations).…”