In a complete redefinition of the concept of “sweet”, an international team of paleontologists has identified the tiniest trace of stegosaurs.
Preserved in stone in the Chinese province of Xinjiang for 100 million years, the footprint is only 5.7 centimeters (2.24 inches) long and was probably made by a baby stegosaurus (ihnogenus) Deltapodus) about the size of a cat, the research team said.
Fascinatingly, although we do not know the exact species of small animals, the press has allowed scientists to conclude that baby stegosaurs may have walked differently than adults.
“This imprint was created by a herbivorous, armored dinosaur widely known as the stegosaurus – a family of dinosaurs that includes the famous stegosaurus,” said paleontologist Anthony Romilio of the Australian University of Queensland.
“Like a stegosaurus, this little dinosaur probably had adult spikes on its tail and bone plates on its back. With a footprint of less than six inches, this is the smallest stegosaurus footprint known in the world.”
We know that stegosaurs lived in the region. Dozens of paths up to 30 centimeters long were found, as well as the remains of skeletons. Elsewhere in the world, stegosaurus tracks rarely exceed 50 centimeters.
Footprints of very young stegosaurs and other armored dinosaurs are incredibly rare compared to other species, and it’s not entirely clear why.
It’s possible that, living in a herd, a lot of their footprints were crossed by larger, heavier adults, but that doesn’t quite explain how babies the footprints of other dinosaur herds survived. Other explanations include rapid growth – the animals may not have been long enough to leave many traces; or that nursery habitats were generally not suitable for preserving footprints.
Whatever the reason for the shortage, somehow a single clue survived. Baby’s three-legged foot pressed into the mud; time turned mud into silt, creating a mold filled with debris, which over time turned into sandstone, creating an outflow of the tiny staircase that survived when the sludge thawed.
Although not much detail has been preserved, the shape of the print was intriguing – it was not elongated like traces of older stegosaurs, the researchers said.
“Stegosaurs usually walked on their heels on the ground, similar to humans, but on all fours, which creates long tracks,” Romilio said.
“A small trail shows that this dinosaur was moving with its heels raised off the ground, much like a bird or a cat does today. We’ve only seen tracks like this before when dinosaurs walked on two legs.”
This harrowing discovery suggests that baby stegosaurs could move more easily and deftly than adults, walking on their toes and transitioning to walking on their heels as they grow. However, with just one footprint, that is impossible to say.
The specific stegosaurus that created it could have had a strange way of walking; or he might have lowered his leg strangely, just for that one step.
“A set of traces of these tiny prints would provide us with an answer to this question,” said paleontologist Lida Xing of the Chinese University of Geosciences, who found the print, “but unfortunately we only have one print.”
The region in which the footprint was found yielded nine different dinosaur trail locations; and a specific set that included a child footprint had 16 other footprints of older stegosaurs. Now that one child’s footprint has been found, the team intends to look for a clue formation that can help us answer these fascinating questions.
The research was published in Palaios.