Side angle image of sauropod footprint. Photo: Jon Hoad

Fifty dinosaur footprints on an island off Scotland, which has been the source of previous tracks, have yielded more clues about the Middle Jurassic period.

The University of Edinburgh team used a drone and tailored software to find the mass of prints in a tidal area at a place on the Isle of Skye called Brothers’ Point, they report in the latest Scottish Journal of Geology.

“This tracksite is the second discovery of sauropod footprints on Skye,” said Paige dePolo, leader of the latest study. “This site is a useful building block for us to continue fleshing out a picture of what dinosaurs were like on Skye in the Middle Jurassic.”

“The more we look on the Isle of Skye, the more dinosaur footprints we find,” added Steve Brusatte, another of the authors, who led the previous look at prints about two years ago.

The location on the island’s northeastern Trotternish Peninsula preserved the prints from 170 million years ago because the shaley limestone was “baked” within the sedimentary layers, according to the paper.

The prints are mostly made up of small sauropod front and rear tracks, they report. However, there are also isolated three-toed prints.

The former have been identified as Breviparopus, a large sauropod, because of the narrow width of the tracks, and the toes of the rear feet. The latter, tridactyl tracks are believed to be Eubrontes – a name for footprints discovered in places like Massachusetts in the 19th century, and which have not been specifically described as a species.

Together, they show the traces of early cousins of the Brontosaurus and the Tyrannosaurus rex – but before dinosaurs would hold sway over the Earth, according to Brusatte.

The footprints show, through their placement and their alignment in the coastal region, that these early dinosaurs were wont to spend time in shallow lagoons then widespread on the planet, according to the paper.

Four of the current authors wrote their last study of a separate set of prints on Skye in the same journal in December 2015. But those prints were found in a location removed from this current discovery – and were not as numerous as those found at Brothers’ Point.

Brothers' Point on Skye. Photo: Steve Brusatte