Dinosaur Farm

Polacanthus Reconstruction: Part 4 ‘We can rebuild it….’

With Christmas and the New Year celebrations over for another year, the priority was to make a start on turning the Minmi model into a Polacanthus.

The modifications required include:

  • A new head - based on Gastonia burgei.
  • A number of spines and plates over the body and the tail.
  • A Sacral Shield over the hips.

I went through my scientific papers on Polacanthus, Gastonia and their relatives to refresh my memory before putting pen to paper. Gastonia has the most complete skeleton of a Polacanthus relative and there are several mounted Gastonia skeletons on display in the United States. The first mounted skeleton was produced by Robert Gaston, Jennifer Schellenbach and James Kirkland (2001) in the Armoured Dinosaurs. They arranged the spines based on the best information available, so I decided to use this as the starting point of my attempt to reconstruct a Polacanthus.


The first thing to do was plan out the arrangement of the spines, scutes, the sacral shield and label them; this would allow me to break the task into ‘bite’ sized chunks.

Over forty spines, a fleshed skull and a sacral shield would need to be sculpted. So I would have my work cut out to get it ready in time for the end of March.

With time ticking the next task was to set-up a workshop space with everything required in easy reach.


Before starting to carve the spines I requisitioned the Children’s area (which explains the Dinosaur pictures on the walls), relocated the Minmi, set-up my drawing table, a heater and stuck my laminated inspirational pictures to the wall. With my Palaeontological Fortress of Solitude complete I was ready to get to work.

Polacanthus Reconstruction: Part 1 ‘Imagination + Wishful Thinking =……’


Royal Mail Stamp: Polacathus by John Sibbick


I have to confess I really like Polacanthus foxi. My infatuation started 20 years ago. I was a teenage volunteer at the Dinosaur Farm and in the intoxicating vapours from acetone (used to clean and repair the ‘Barnes High Sauropod’) on a warm sunny day, the volunteers were all deep in conversation about our favourite dinosaurs.

Now our ‘local’ dinosaurs weren’t the household names of A-list celebrity dinosaurs that trip off the tongue;  T.rex, Triceratops, Stegosaurus, Diplodocus and even Velociraptor (newly elevated to cult status due to the success of the Jurassic Park movie). We had the old school dinosaurs of Iguanodon, Hypsilophodon, and Polacanthus and predators including a Theropod referred to as Megalosaurus (but identified as Neovenator in 1996), the fish-eating Baryonyx, and Aristosuchus, Calamosaurus, Calamospondylus, Ornithodesmus (later identified as the Pterosaur Istiodactylus in 2001) and Thecocoelurus (a number of assorted small Theropods known from a hand full of bones).

I honestly didn’t have a favourite. Sure I could repeat the well trod names of famous Theropods but I didn’t have an emotional response to these dinosaurs other than the ‘coolness’ associated with them. As wannabe palaeontologists we talked about what we wanted to specialise in when we ‘qualified’ with all the naivety that comes with [Imagination + Wishful Thinking = Talking Nonsense]. It seemed that everyone wanted to research Theropods. I realised that if I was going to become a Palaeontologist I would need to broaden my interest as very few Palaeontologists exclusively specialise in Theropods, there isn’t enough of them (never mind the lack of fossil bones due to their relative rarity) to go around!

So I thought about the options and in the end I realised that there wasn’t much interest in Polacanthus.  It looked like a giant sheep with a shield over its hips, covered in spikes. It might not have the ‘coolness’ associated with Theropods, the sheer mass of a Sauropod or the relative abundance of the Ornithopods Iguanodon and Hypsilophodon but it held its own in the Wealden floodplain of the Lower Cretaceous 125 million years ago and deserved respect.

Over the next few years I had read everything written about it, visited the collections of Polacanthus material held in the bowels of the Natural History Museum in London (BMNH), the Museum of Isle of Wight Geology and even a privately owned specimen known as ‘Spike’. My infatuation was complete save for the fact I had never found a piece of Polacanthus on the beach.