The first juvenile specimens of Plateosaurus engelhardti from Frick, Switzerland: Isolated neural arches and their implications for developmental plasticity in a basal sauropodomorph

• Main Authors: Hofmann, Rebecca, Sander, P. Martin
• Format: Other/Unknown Material
• Language: unknown
• Published: PeerJ 2014
• Subjects: Greenland
• Online Access: http://dx.doi.org/10.7287/peerj.preprints.325; https://peerj.com/preprints/325v1.pdf; https://peerj.com/preprints/325v1.xml; https://peerj.com/preprints/325v1.html

The dinosaur Plateosaurus engelhardti is the most abundant dinosaur in the Late Triassic of Europe and the best known basal sauropodomorph. Plateosaurus engelhardti was one of the first sauropdomorph dinosaurs to display a large body size. Remains can be found in the Norian stage of the Late Triassic in over 40 localities in Central Europe (France, Germany, Greenland and Switzerland). Since the first discovery of P . engelhardti no juvenile specimens of this species had been found. Here we describe the first remains of juvenile individuals, isolated cervical and dorsal neural arches. These were separated postmortem from their respective centra because of unfused neurocentral sutures. However the specimens share the same neural arch morphology found in adults. Morphometric analysis suggests a body lengths of the juvenile indivduals that is greater than those of most adult specimens. This supports the hypothesis of developmental plasticity in Plateosaurus engelhardti that previously had been based on histological data only. Alternative hypotheses for explaining the poor correlation between ontogenetic stage and size in this taxon are multiple species or sexual morphs with little morphological variance or time-averaging of individuals from populations differing in body size.