Bite traces on dicynodont bones and the early evolution of large terrestrial predators

Abstract

Niedźwiedzki, G., Gorzelak, P. & Sulej, T. 2010: Bite traces on dicynodont bones and the early evolution of large terrestrial predators. Lethaia, Vol. 44, pp. 87–92. Dicynodont (Synapsida: Anomodontia) bones from the Late Triassic (late Norian/early Rhaetian) of Poland yield characteristic tooth marks that can be attributed to three ichnotaxa (Linichnus serratus, Knethichnus parallelum and Nihilichnus nihilicus). The general shape and dimension of these traces perfectly match the dental morphology of a co‐occurring carnivorous dinosaur. It is therefore concluded that early carnivorous dinosaurs were feeding on dicynodonts. This discovery constitutes one of the oldest evidence of dinosaur predator–prey interaction. It is suggested that an evolutionary increase in the size of dicynodonts across the Late Triassic may have been driven by selection pressure to reach a size refuge from early dinosaur predators. □Bite traces, dicynodonts, dinosaurs, predation, Triassic.

Tyrannosaurid-like osteophagy by a Triassic archosaur

“…A few of the bones exhibit grooves and pits that are similar to bite traces found on dicynodont bones from the locality (Fig. 5) 10,12 . The bones are fragmented and range from submillimetre to centimetre scale.…”

“…The material of S. wawelski is associated with numerous bones of a large dicynodont as well other vertebrates. Many of these bones show deep bite marks; one juvenile dicynodont fibula has had its distal head bitten off 12 . The size of the bite marks matches the teeth of S. wawelski 12 , which suggests that this predator was at least an occasional osteophage.…”

“…Many of these bones show deep bite marks; one juvenile dicynodont fibula has had its distal head bitten off 12 . The size of the bite marks matches the teeth of S. wawelski 12 , which suggests that this predator was at least an occasional osteophage. We decided to investigate this possibility by analysing ten relatively large coprolites (87–250 mm long and around 30–50 mm wide; Table 1) from Lisowice by both classical analytic techniques and phase-contrast synchrotron microtomography (PPC-SRμCT).…”

Mammal-like tooth from the Upper Triassic of Poland

“…The vertebrate macrofossil assemblage from the Lipie Śląskie clay-pit consists mainly of terrestrial rather than am-phibious or aquatic tetrapods (Dzik et al 2008a, b;Niedźwiedzki et al 2011Niedźwiedzki et al , 2012. Remains of a huge dicynodont are the most abundant finds and are followed by remains of the large predatory archosaur Smok wawelski, small to medium-size archosaurs (dinosauromorphs, dinosaurs, and poposaurids) and other archosauromorphs.…”

An elephant-sized Late Triassic synapsid with erect limbs

“…Selection pressures on some aspects of lifestyle or ecology were likely drivers of the evolution of the distinct posture of Lisowicia among dicynodonts. Increase in the body size of dicynodonts across the Late Triassic may have been driven by selection pressure to reach a size refuge from large predators (24). It is possible also that the gigantism of the latest dicynodonts was a metabolic adaptation that allowed these animals to maximize food retention time and consequently the energy gain (25).…”