Wednesday 23 February, 4 PM CET (ZOOM WEBINAR)
JIMMY DE ROOIJ
ABSTRACT: Annual field expeditions during 2013-2019 to eastern Wyoming, USA by Naturalis, the national natural history museum of the Netherlands, resulted in the discovery of a monospecific bonebed containing the remains of at least six individuals of Triceratops, an iconic, herbivorous horned dinosaur from the Late Cretaceous. With over 1100 fossil bone elements, this is the third -and largest Triceratops bonebed to be reported. The uniqueness of this site is characterized by the high amount of post-cranial material of different-sized individuals, resembling subadult –and adult ontogenetic stages. Morphological –and histological observations of prepared bone material confirm these observations. Detailed geological fieldwork showed that the remains are enclosed in an organic-rich siltstone and that the animals succumbed during a miring event. High-resolution grain-size analyses indicated further post-mortem disarticulation, showing the presence of two subsequent crevasse splays, both overlapping – and displacing the remains during fossilization. The described research will focus on mapping the growth pattern of Triceratops in more detail using a large-scale histological approach in a full-skeletal analysis. These patterns will be compared among other ceratopsian taxa in an evolutionary framework to better understand how growth rates in this group of dinosaurs have developed over time. Isotopic analyses of tooth enamel will measure the oxygen-, carbon- and strontium content of the fossil material, providing information on temperature, diet, and migration, respectively. The acquired data will be combined with the current results on the taphonomy of the site, to answer questions regarding the origin of the bonebed and ultimately shine new lights on the development and behavior of Triceratops.