166-million-year-old footprint of a Megalosaurus-like dinosaur found along the Yorkshire Coast (UK). Credit: Marie Woods, local archeologist who found the footprint.
Today, photos capture many moments in life, from the mundane to the significant. Unfortunately, iPhones weren’t around 166-million-years-ago to document the rise and fall of dinosaurs. But that doesn’t mean those moments are lost in time—especially where there was mud.
Researchers in the UK recently found an almost 1-meter-long footprint belonging to a Megalosaurus-like dinosaur that roamed a popular—and muddy—basin 166-million-years-ago. Archeologists believe the unusual footprint captures the single moment in time when the dinosaur rested or crouched down.
“It’s fun to think this dinosaur might well have been strolling along a muddy coastal plain one lazy Sunday afternoon in the Jurassic,” said study author Dean Lomax, professor in the Department of Earth and Environmental Sciences at the University of Manchester.
More than that, the three-toed print is scientifically significant for its rarity. It is only one of six similar prints found along the Yorkshire Coast in an area referred to as “Dinosaur Coast,” as thousands of footprints and many fossils have been recovered from the location over the years.
Still, it’s not every day that a footprint measuring 80-centimeters-long is discovered.
“This important discovery adds further evidence that meat-eating giants once roamed this area during the Jurassic. The type of footprint, combined with its age, suggests that it was made by a ferocious Megalosaurus-like dinosaur, with a possible hip height between 2.5 and 3 meters,” said John Hudson, lead author of the paper and local geologist.
Interestingly, the footprint shows an elongated metapodium, which archeologists believe may be the result of resting or crouching behavior. Alternatively, the extended length could indicate the dinosaur slipped forward a bit, leaving behind an exaggerated length of its metapodium. A study reviewer proposed a third interpretation that combines the two prevailing thoughts: the dinosaur originally left evidence of its elongated metapodium from a crouched position, but then accidentally slid forward before standing upright and moving on—further exaggerating the length of its already-elongated metapodium.
The bed from which the footprint was found comes from Burniston Bay, a particular hotspot of footprints from a variety of dinosaurs preserved in rocks known as the Ravenscar Group. These footprints were formed during the Middle Jurassic, which lasted from around 174 to 163.5 million years ago. At the time, northern Yorkshire was part of a coastal floodplain, whose muddy shores would have been ideal for preserving footprints.
The Megalosaurus-like footprint is preserved at the base of a thin sandstone bed in Burniston Bay. The study authors say it is not clear, however, whether the dinosaur walked on the surface of the crevasse flow deposit after it settled (before it consolidated with the bay) or if the dinosaur traversed the area while igneous rocks were falling into place on top of existing sediment. The dinosaur could have even left the footprint after the crevasse flow had already been covered by sediment. The study authors say the last scenario may explain the incorporation of the muddy layers within the disturbed parts of the sandstone bed.
Pollen recovered from the bed suggests the surrounding landscape was covered in large ferns, as well as conifer and Gingko trees. This vegetation would have attracted a variety of herbivorous dinosaurs, including sauropods and stegosaurs—and their predators. From the thousands of footprints known from the Ravenscar Group, about 25 different types have been identified.
“Although these different types do not necessarily represent the same number of different dinosaurs, they do indicate a diverse ecosystem of animals, including both carnivores and herbivores that roamed the Jurassic coastal plain and fluvial complex 160-175 million years ago,” said study author Mike Romano from the University of Sheffield, who has worked on the Yorkshire Coast for over 20 years. “The prints also allow us to interpret their behavior. We have records of walking, running and swimming dinosaurs.”
And now, crouching dinosaurs.