This week I'm taking us back over 360 million years to the Devonian Period, a long time before even the dinosaurs popped up, when the oceans were ruled by a terrifying fish that's been fascinating me recently, and one that I unfortunately missed getting to see at St Marie this year: Dunkleosteus.
Picture a creature built like a tank with jaws that could slice through anything unlucky enough to swim by. Dunkleosteus wasn’t your average fish, it was an armoured placoderm, meaning its head and front body were covered in thick bony plates instead of scales. The rest of its body was probably more flexible and smooth, and built for bursts of speed.
It's tricky to give it a size, as only the head parts have really been found, but by looking at its relatives it's estimated it could have been around 4.5m long, based on the size of the head.
While it didn’t have true 'teeth', its jaw edges were sharpened bone plates that acted like self-sharpening blades, backed up by one of the most powerful bites in history. Think ancient can-opener meets guillotine!
I’ve sketched Dunkleosteus' fossilized head this week to show that awesome armour plated face. Imagine this thing coming to say hello whilst your snorkeling along happily minding your own business!
Fossils of Dunkleosteus' head parts have been found in North America, Morocco, and Europe, but due to the skeleton being made of cartilage, those bits haven't yet been found as soft bits don't tend to fossilize as easily.
It was the ultimate apex predator of its time, and probably scared everything else into trying to hurriedly evolve armour of their own!
Fun fact: Estimates from mechanical modeling suggest Dunkleosteus could whip open its mouth in around 1/15th of a second, creating a vacuum to pull in its pretty, then generate a bite force of around 80,000psi at the tips of it's jaw! Now that would ruin your day if you were a fish in the Devonian oceans!
