Palaeontologists working on the Isle of Skye have uncovered around 50 dinosaur footprints, including track marks compatible with Stegosaurus. The discovery points to the tremendous ecological diversity of the region some 170 million years ago.
That Scotland once hosted a wide assortment of dinosaurs during the Jurassic period may come as a surprise, given the region’s temperate climate today.
“Jurassic Scotland was nothing like modern Scotland,” explained Steve Brusatte, a palaeontologist from the University of Edinburgh and a co-author of the new study, in an email to Gizmodo.
Back then, Scotland was still part of an island, but the region was hot and humid, with a subtropical climate similar to Florida or Spain today, said Brusatte. Dinosaurs walked along beaches and lagoons, leaving behind footprints that became fossilised over time. Today, rocks carved by ancient rivers are slowly revealing these hidden fossilised treasures, thanks to the slow and steady processes of erosion.
In general, fossils from the Middle Jurassic (164 million to 174 million years ago) are rare, which is a shame given how dinosaurs spread and diversified during this critical time period. Indeed, this period witnessed the first birds, the earliest tyrannosaurs and stegosaurs, and the rise of gigantic sauropods, with their long neck and tails.
Hence the importance of the Isle of Skye – the location of the new track prints – for palaeontologists.
Steve Brusatte and PhD student Paige dePolo, who led the research, with fossil dinosaur tracks on the Isle of Skye. (Image: Steve Brusatte)
The new research, led by Paige dePolo from the University of Edinburgh and published yesterday in PLOS One, describes two new dinosaur trackways containing around 50 prints, exposing a diverse Middle Jurassic ecosystem as it existed 170 million years ago. The trackways were found at a location called Brothers’ Point, which has previously produced other dino prints. Brusatte said the new sites are below the tide line on a promontory of rock that sticks out into the Atlantic, and waves lap across them each day, which made them difficult to detect.
Brusatte, who led the field team and is dePolo’s PhD supervisor, said one of the track sites was discovered by Paulo Pereira, who was a visiting PhD student from Brazil at the time.
“I think this project is a prime example of how students are making so many of the important discoveries and doing ground-breaking work these days,” Brusatte told Gizmodo.
The Deltapodus tracks, which is indicative of stegosaurs. (Image: Steve Brusatte)
Among the most exciting footprints discovered is a morphotype known as Deltapodus. Palaeontologists – because they’re a careful bunch who don’t like to jump to conclusions – refrain from immediately describing a footprint or handprint as belonging to a specific species, instead assigning them unique designations, while proposing likely candidates in terms of provenance. In the case of Deltapodus, this morphototype is associated with stegosaurs or stegosaur-like dinosaurs – four-legged beasts featuring those iconic diamond-shaped plates along their backs.
This is the first record of Deltapodus on the Isle of Skye, and they’re now one of the oldest Deltapodus prints in the fossil record. Stegosaurs, as these prints suggest, were likely members of Scotland’s Middle Jurassic ecosystem.
“It seems like stegosaurs were beginning to diversify and prosper about 170 million years ago – a time when dinosaurs were blossoming, but which is recorded by few fossils sites around the world,” said Brusatte.
Other footprints found at Brothers’ Point include tracks “unequivocally made” by carnivorous two-legged theropods, explained Brusatte, but other three-toed track marks were more difficult to discern, possibly originating from other carnivores or even an early relative of duck-billed herbivores, according to the research. Future discoveries will be required for more precise classifications.
These new trackways, along with others previously found on the Isle of Skye, shows that the island was a “real-life Jurassic Park,” said Brusatte, featuring “big ones, small ones, meat-eaters, plant-eaters, giant long-necked ones, plate-backed ones, living together, thriving,” he said.
The Isle of Skye, as the new research attests, is becoming one of the most important places for palaeontologists seeking to unlock the mysteries of the Jurassic period. They’ll just have to remember to bring their kilts.
Featured image: Jon Hoad