Byronosaurus jaffei

I. INTRODUCTION Troodontidae are a group of small, bird-like theropods belonging to the clade Paraves. The clade is defined as a stem-based monophyletic group containing Troodon formosus and all coelurosaurians closer to it than to Velociraptor mongoliensis or Passer domesticus (Turner, Makovicky & Norell, 2012) (Fig. 1).

Loading metrics Open Access Peer-reviewed Research Article Citation: Kellermann M, Cuesta E, Rauhut OWM (2025) Re-evaluation of the Bahariya Formation carcharodontosaurid (Dinosauria: Theropoda) and its implications for allosauroid phylogeny. PLoS ONE 20(1): e0311096.

Highlights • Perinatal dinosaurs reported from the Late Cretaceous of northern Alaska • A diverse assemblage of dinosaur species reproduced in the Arctic • Large- and small-bodied taxa were nonmigratory year-round residents • Paleoenvironmental constraints suggest polar-specific life history strategies Summary The unexpected discovery of non-avian dinosaurs from Arctic and Antarctic settings has generated considerable debate about whether they had the capacity to reproduce at high...