The macroevolutionay patterns of Mesozoic mammals

forthcoming

Since their origination in the Late Triassic, a series of evolutionary innovations throughout the Mesozoic Era resulted in the morphological, physiological, and ecological bauplan for mammals and set the path to their modern success. Due to the incomplete nature and limited access to 3D data for Mesozoic mammal specimens, their evolutionary morphology remains unexplored under a quantitative framework, creating a major knowledge gap in vertebrate evolution. This proposal aims to investigate macroevolutionary patterns of early mammals during the Mesozoic using advanced 3D geometric morphometric techniques. It will generate a new dataset covering 30 well-preserved crania and over 180 upper and lower dentition across major clades of Mesozoic mammals, using advanced 3D scanning technologies, including X-ray Computed Tomography, Synchrotron and Neutron Tomography. Cutting-edge landmark-based and landmark-free morphometric methods will be used to quantify shape variation and underlying effects of allometry and ecological traits. These analyses will reveal trends of cranial evolution, testing whether the cranial morphology in Mesozoic mammals evolved gradually or followed a punctuated pattern. It will also reveal shifts of phenotypic integration and modularity across the tooth row, providing insights into the mechanisms that shaped unusual key innovations of heterodonty and dental complexity in mammals and how that related to other changes in skull morphology through the Mesozoic. The proposed research will not only fill a significant knowledge gap in vertebrate evolution but will also equip the applicant with essential skills in quantitative approaches urgently needed in Chinese paleontology, positioning the applicant as a leading independent researcher in this field.