We've been given exclusive access to a brand new study examining the chemistry of a mosasaur tooth found within the Late Cretaceous Hell Creek Formation, North Dakota. The remarkable circumstances of how this tooth was discovered meant that multiple lines of chemical evidence could be reliably gathered, each acting as a powerful palaeoenvironmental proxy providing clues as to how and where this giant aquatic predator lived. The results of the study now mean that a revision of mosasaur palaeoecology is required and that food webs in one of the world's most famous fossil deposits might need redrawing.

Joining us in this episode are the lead authors Nathan Van Vranken (Eastern West Virginia Community and Technical College) and Melanie During (Uppsala University & Vrije Universiteit Amsterdam). Their study "King of the Riverside", a multi-proxy approach offers a new perspective on mosasaurs before their extinction is open access and available in BMC Zoology now!

The iguanodontians were an incredibly successful group within the Cretaceous. They could reach incredible sizes, with the largest species even matching the proportions of some sauropods, and they also had an incredible palaeogeographic range, meaning that their remains are found all over the world today. In the late Jurassic, they were a lot less diverse and much smaller, so the late Jurassic and early Cretaceous are key times for understanding the evolution of this group.

Cariocecus bocagei is a newly described iguanodontian from the Early Cretaceous of Praia do Areia do Mastro, Portugal. Whilst it is only know from a partial skull, there are numerous useful characteristics that help identify it as a new species and fill in our understanding of iguanodontians in this important time in their evolution.

Joining us in this episode is Dr Filippo Bertozzo of the Royal Belgian Institute of Natural Sciences.