Jimmy de Rooij


I have always been amazed by the vast shapes and sizes animals come in. For me, many  extinct animals look like creatures from another world. Here at Naturalis I got the opportunity to actually study these creatures! My research focusses on the growth, development and behaviour of horned dinosaurs, especially Triceratops. By combining the latest technology, I try to uncover how these dinosaurs lived their life!


Dinosaurs, Triceratops, histology, , stable isotopes, bone-beds, ontogeny, ceratopsians

MSc Jimmy de Rooij

PhD Student
Vertebrate evolution, development and ecology


+31 6 30024127 (mobile)

Research areas

Horned dinosaurs were one of the most iconic dinosaurs. These giants, such as Triceratops, are well-known in popular media, but how much do we actually know? 

The discovery of a large monospecific death assemblage containg the remains of at least five Triceratops individuals provided an unique opportunity to study these extinct animals in great detail. 

I try to combine different techniques to create a better understanding of Triceratops biology:

  • Bone histology provides a microscopic look inside fossil bones an helps to reconstruct metabolism and growth strategies. 
  • Stable isotopes help to reconstruct the last days of this particular group of Triceratops. What did they eat? Where did they go?
  • XRF analysis of fossil elements will reveal the taphonomic history of this bonebed.

I apply this multidisciplinary approach to answer long-standing questions on Triceratops biology and behaviour. Does this death assemblage represent a social group (a herd) or merely an accumulation of individuals overtime?

Bot histologie


Some topics that are close to my research area, including the Triceratops expeditions!




As a PhD Candidate, I supervise BSc & MSc students on various palaeobiological subjects. These topics mainly focus on the Triceratops material housed at Naturalis.

    List of (finished) projects:

    Charlotte Furer & Sybrand Lucassen (BSc Leiden University) - Osteohistology of Triceratops ribs and vertebrae

    Megan Hulscher (MSc Leiden University) Palaeoecology of Triceratops based on oxygen and carbon stable isotopes

    Nadia de Waal (Breda University of Applied Sciences) Reconstruction of Triceratops fossilisation events through scientific illustration

    Baby Trike



    Some outreach

    Dutch dinosaur podcast soon! : DinoCast (www.dinocast.nl)