Origin and Evolution of Non-Hadrosaurid Ornithopod Dinosaurs

• Applicant: Privatdozent Dr. Alberto Prieto Marquez, Ph.D.
• Subject Area: Palaeontology
• Term: from 2014 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 248485444

Ornithopod dinosaurs are one of the most successful radiations of Mesozoic vertebrates, consisting of obligatory to facultative bipedal and digitigrade animals that colonized every continent over a 100 million years time span. Ornithopods are an important grout because: i) understanding how they achieved their cosmopolitan distribution may help elucidate how geological events affected the evolution and distribution of terrestrial faunas; ii) the abundance and high quality of their fossil record allows for studying how reptilian anatomy relates to biomechanical function and ecology; iii) and the large sample sizes and growth series available for various species allow for studying how anatomical variation relates to species recognition, reproductive behavior, intraspecific variation, ontogeny, and population biology. These questions can be best approached in a phylogenetic context to provide an all-encompassing evolutionary understanding for the group. However, a well-resolved and robust phylogeny of these animals does not exist. The core goal of this project is two-fold: providing a well-resolved and robust phylogeny of ornithopod dinosaurs and using this phylogeny for addressing a number of questions on the evolutionary biology of these animals. These goals will be reached in five phases. Phase 1: comparative anatomy and morphometric character analysis for the recognition and documentation of new phylogenetically informative characters, as well as re-evaluation of previously known ones; the basal iguanodontian ornithopod Dysalotosaurus lettowvorbecki will serve as a model for understanding how each element and anatomical region of the skeleton changes throughout ontogeny and also among individuals of the same age/ontogenetical stage. Phase 2: taxonomic revision of poorly known taxa based on the information provided by phase 1 and first hand examination of specimens. Phase 3: integration of results from phases 1 and 2 for creating a taxon-character state matrix for phylogenetic analysis. Phase 4: phylogenetic inference of the interrelationships of ornithopod species via maximum parsimony analysis. Phase 5: usage of the phylogeny derived from phase 4 for addressing questions on the palaeobiology and evolutionary history of ornithopods: which attributes drove the diversification of these animals? How did body size evolve in Ornithopoda? Could any changes in body size be correlated with the evolution of other morphological characters and/or other factors (e.g., paleoenvironmental, etc)? Where did ornithopods originate and how did they achieve their cosmopolitan distribution? Finally, the phylogeny will also be used for soft-tissue and biomechanical inferences on functional morphological aspects of ornithopod anatomy, setting the groundwork for more in-depth future research on the functional morphology of various character complexes (e.g., feeding-related characters, locomotion-related characters, etc.) of these dinosaurs.

• DFG Programme: Research Grants
• Participating Institution: Museum für Naturkunde; Leibniz-Institut für Evolutions- und Biodiversitätsforschung (MfN)
• Participating Persons: Dr. Heinrich Mallison; Dr. Daniela Schwarz