Numerous traces found along Scotland's coast demonstrate that enormous, long-necked dinosaurs formerly roamed this area.

The footprints constitute the biggest dinosaur skeleton yet discovered in Scotland. They also demonstrate that sauropods, which were among the biggest dinosaurs ever, were at home near the water.

Long-standing controversy surrounds the enormous dinosaurs' relationship to water. Paleontologists believed sauropods had to wallow in swamps where the water could support their enormous heft throughout much of the 20th century. The "Dinosaur Renaissance" of the 1970s and 1980s, however, removed this outdated vision thanks to discoveries. For their size, sauropods found out to be surprisingly light, more likely to float than to sink to the bottom of a lake. Instead of sweltering wetlands, a new perspective showed sauropods traversing woods.

The new footprints discovered on the Isle of Skye now add to the mounting evidence that some sauropod dinosaurs frequented ancient coastlines and lagoon borders. The Isle of Skye site's geology provided unmistakable proof that the dinosaurs were roaming a brackish lagoon.

A Huge Find

The University of Edinburgh paleontologist Stephen Brusatte examined the Isle of Skye location after a geologist found bones there. "We had gone out to a lonely stretch of coast on the far northeastern tip of the island," he recalls. According to Brusatte, he and fossil fish expert Tom Challands found what appeared to be a pothole after spending the day largely hunting shark teeth and other small fossils. It was the imprint of a dinosaur.

This first discovery led to the discovery of a series of tracks that covered an area measuring roughly 49 feet (15 meters) by 82 feet (25 meters).

But the tracksite's vastness isn't the only impressive aspect. The Middle Jurassic period, more than 161 million years ago, is when the Isle of Skye footprints were created. This is "one of the least understood periods in dinosaur evolution," according to Brusatte. The traces provide a fresh look at the types of dinosaurs that inhabited the region and their behavior throughout this enigmatic period.

Anthony Martin, a paleontologist at Emory University, adds that dinosaur bones are uncommon in Middle Jurassic rocks, and even fossil skeletons can be moved from the site of the animal's demise. But tracks are a another matter. Martin asserts that the study of footprints "is extremely valuable for filling in gaps in our understanding of dinosaur evolution."

It is unclear exactly which dinosaurs left the footprints. It's typically impossible to link a skeleton foot to a footprint unless a dinosaur actually perishes in its footsteps.

However, the tracks still include enough information for Brusatte and his coauthors to classify them as sauropod dinosaurs, which moved with their legs very close to one another along the midline and included the controversial Brontosaurus and its relatives. A Middle Jurassic dinosaur named Cetiosaurus, which also happens to be one of the first dinosaurs ever named, is an excellent candidate for this kind of trackmaker, according to Brusatte.

Animals in the Lagoon

Another surprise was the old ecosystem in which these dinosaurs roamed.

Why sauropods consistently avoided the edges of seas, lagoons, and wetlands at the prehistoric Isle of Skye and other places across the world is still a mystery to paleontologists. According to Brusatte, it's possible that the lagoons and beaches offered a food source, safety from predators, or some other allure.

Martin concurs, pointing out that the discovery of sauropod tracks in coastal habitats is not particularly surprising given that these areas "provided paths of least resistance for sauropods moving from one place to another" because of their flat, accessible shorelines, where predatory dinosaurs would have had more difficulty ambushing prey due to the absence of cover.

So, even though sauropods were primarily land creatures, some of them were at least ok with getting their feet a little wet. As Brusatte points out, "Dinosaurs were probably capable of doing a lot more and living in a lot more places than we give them credit for."