A Yorkshire Coast Rocks blogpost for Hidden Horizons
Birds are theropod dinosaurs (https://www.scientificamerican.com/article/how-dinosaurs-shrank-and-became-birds/), so when a herring gull steals your ice cream on Scarborough seafront, console yourself with that thought. If that’s insufficient consolation and you need the distraction of actual Jurassic dinosaurs, Scarborough seafront is also an excellent place to be.
The rocks that make up the town’s South Cliff are Middle Jurassic in age, around 165 million years old. They are mostly sandstones, formed in rivers that were flowing into a coastal plain. Plenty of plants grew on the riverbanks and the floodplain: we find lots of plant fossils in the sandstones.
That’s not all, though. Some of the layers are disturbed by huge, bowl-shaped, sand-filled depressions, and other layers by large, three-toed impressions – these are the fossilized footprints of giant, plant-eating dinosaurs, such as sauropods, and of giant, plant-eating-dinosaur-eating dinosaurs, the theropods!
That’s not all, though. Some of the layers are disturbed by huge, bowl-shaped, sand-filled depressions, and other layers by large, three-toed impressions – these are the fossilized footprints of giant, plant-eating dinosaurs, such as sauropods, and of giant, plant-eating-dinosaur-eating dinosaurs, the theropods!
At least 50 dinosaur footprints can be seen in the rocks of Scarborough’s South Cliff. We can show you some of the best on one of our regular dinosaur footprint hunts: https://hiddenhorizons.co.uk/collections/scarborough-dinosaur-walks. Many more tracks are found along the Yorkshire coast, from Staithes to Cayton Bay, but dinosaur bones are incredibly scarce. So, how do we go about working out which reptilian monsters were stalking Yorkshire’s Jurassic rivers and shorelines?
First, we need to examine the fossil footprints carefully. Analysing the details of their size and shape can help us narrow down the likely trackmakers; especially if we also compare the footprints with the feet of known dinosaur skeletons.
To refine this further, we can then look at what dinosaurs are known from rocks of the same age, elsewhere in the UK. For the Middle Jurassic, where Scarborough’s rocks lack dinosaur bones, our best bets are Oxfordshire (https://oumnh.web.ox.ac.uk/megalosaurus-and-oxfordshire-dinosaurs) and Rutland (https://www.leicestermuseums.org/media/cmhmoasc/dinosaur-gallery-activity-sheet.pdf), where various skeletons have been found.
By taking this approach, we might conclude that Scarborough’s large sauropod footprints were made by beasts such as the ‘whale-lizard’ Cetiosaurus, and its big, three-toed tracks by theropods like Megalosaurus.
Wikimedia images Megalosaurus and Cetiosaurus
A couple of problems remain, though. One is that some of the ‘Megalosaurus’ footprints are bigger than the skeletons suggest they should be. Did Yorkshire have a Megamegalosaurus? Another is that there are other prints – such as small, three-toed tracks – for which no candidate dinosaur skeletons have been found. Were there lots of small dinosaurs which we’ve not identified yet, or are they simply the prints of juvenile megalosaurs?
Either way, there’s plenty more dinosaur detective work to be done on the Yorkshire coast. Sign up for a Scarborough Dinosaur Walk and begin your training!
More about ‘Chalking With Dinosaurs’ here – https://fossilhub.org/category/outreach/chalkingwithdinosaurs/
Dr Liam Herringshaw is a Palaeontologist who runs fossil hunting tours and expert walks with Hidden Horizons and manages the Yorkshire Fossil Festival.
December 2021
#YorkshireCoastRocks
