Late Jurassic teeth of plesiosauroid origin from the Owadów-Brzezinki Lägerstatte, Central Poland

Abstract

Owadów-Brzezinki is currently one of the most promising Upper Jurassic sites in Central Poland, with a wide array of both vertebrate and invertebrate fossil fauna present. The discoveries of large-bodied marine reptiles fossils such as ichthyosaurs, turtles, and marine crocodylomorphs attracted attention to the location. A particular Mesozoic marine group, plesiosaurs, remained to be found, and in this report, we note four isolated teeth with distinguishing apicobasal ridging pattern and elongated, conical shape characteristic for plesiosaurians. The outcomes of the Principal Coordinates Analysis (PCoA) of the largest and most complete tooth specimen ZPAL R.11/OB/T4 enabled us to confirm its classification as Plesiosauroidea. This discovery affirms the importance of the site as the area of mixing between Boreal and Tethyan faunas, expanding the broad spectrum of fossil taxa found in this location. Together with previous findings of plesiosaur material in a nearby region, it provides the evidence for the presence of Plesiosauroidea in Owadów-Brzezinki Lägerstatte.

Oldest record of Machimosaurini (Thalattosuchia, Teleosauroidea): teeth and scavenging traces from the Middle Jurassic (Bajocian) of Switzerland

“…These three major dental characteristics of the group [12,29] set them apart from ichthyosaur and plesiosaur/pliosaur teeth. In these other marine reptile groups, apicobasal enamel ridges remain usually separate or show few anastomosing junctions [9,[34][35][36][37]; in ichthyosaurs in particular, enamel ridges are formed through scalloping of the enamel-dentine junction rather than solely through thickening of the enamel layer [38]. The thickened enamel cap (more than 0.5 mm) of the crown, underlying massive dentine patch with little pulp cavity expansion towards the apex and overall tooth robustness, can further be interpreted as indicative of a macrophagous or durophagous diet [34].…”

From Neoproterozoic sedimentation on the Peri-Gondwanan extended shelf to the Variscan collision of terranes. The history preserved in the Kamieniec Ząbkowicki metamorphic belt and the Doboszowice metamorphic complex

“…4), crocodyliforms and teeth of plesiosauroids (Fig. 5) with a remarkably good quality of preservation Szczygielski et al, 2018;Weryński, Błażejowski 2023).…”

“…Certainly, some of the most spectacular discoveries in this setting are related to the vertebrate fauna. Most prominent taxa of vertebrates discovered so far are represented by the ichthyosaur Cryopterygius kielanae (Tyborowski, 2016), the pancryptodiran turtle Owadowia borsukbialynickae (Szczygielski et al, 2018) and isolated plesiosaur teeth (Weryński, Błażejowski, 2023). Other verte-brate taxa are represented by Actinopterygii and Elasmobranchii Błażejowski et al, 2015) and marine crocodylomorphs , with additional shore fauna represented by insects, terrestrial crocodylomorphs, and possibly pterosaurs .…”

“…Among these substantial actinopterygians, there exist macropredators belonging to Caturoidea and Pachycormidae, as well as durophagous Pyncno dontiformes. In the latest study of these large predators conducted by Weryński et al (2023), an exploration into the microstructural and mor pho logical attributes of Caturoidea and Pachycormidae teeth from the Owadów-Brzezinki site was undertaken. The findings indicate the potential existence of niche partitioning among these comparably sized predatory fish.…”