PhD: 40Ar/39Ar dating the evolution of latest Cretaceous dwarf dinosaurs from Transylvania (western Romania) and implications for the K-Pg extinction

One of the largest extinctions in Earth history occurred at the Cretaceous-Paleogene (K-Pg) boundary. Most information on the causes, tempo and selectivity of the extinction in the continental realm comes from one part of the world: western North America. However, in recent years, Europe has emerged as another potentially significant source of data. Romania, with its remarkable fauna of dwarf dinosaurs, endemic primitive mammals, archaic crocodyliforms and giant pterosaurs that once lived on a tropical island, holds promise as its continental deposits are interbedded with volcanic rocks that are suitable for high-precision radio-isotopic dating. This project aims to [1] map in detail the field relationships between the volcanic and sedimentary units, and to [2] date the volcanic rocks from the Transylvanian area using the 40Ar/39Ar method. The goal is to constrain the ages of the main vertebrate fossil-bearing successions and to place the different vertebrate assemblages within a robust, accurate and precise chronostratigraphic framework. This will allow identification of potential faunal evolutionary trends as the Transylvanian faunas approached the K-Pg boundary.