The Dinosaur Everyone Thought Was Lonely May Have Had Friends After All

For several decades, it was widely believed that Stegosaurus was a lonely dinosaur that walked leisurely in the Jurassic era without interacting with others. The large back plates, tail spikes, and small brain of this dinosaur became subject to various jokes and oversimplified images in books, movies, and museum displays. Recently, however, scientists have started questioning these perceptions. And this time, the evidence does not come from skeletons; instead, it comes from fossilized footprints.

In a 2024 study published in the journal Scientific Reports, investigators analyzed trackways attributed to stegosaurs and discovered signs of gregariousness. Specifically, as researchers indicate, they have obtained the most convincing ichnological evidence ever gathered regarding the possible group nature of Stegosaurus behavior.

The study examined Deltapodus tracks that are traditionally associated with stegosaurs. Using comparative methods and three-dimensional modeling, the researchers analyzed numerous samples collected in the Iberian Peninsula. The results are significant because Stegosaurus tracks have been difficult to identify precisely for some time now, and therefore, it was complicated to learn more about their behavioral patterns.

Why footprints matter in dinosaur science

While fossils allow for reconstructions of what an animal looked like and its likely mode of movement, trackways allow us to see something much closer to the moment itself. As pointed out by trace paleontologists, tracks can give valuable insights into the pattern of animal movement, grouping, and possible interactions.

According to Smithsonian Magazine and other paleontological sources, fossilized tracks can offer some information about dinosaurs' behavior that is difficult or impossible to gain from fossilized bones, since the former show how dinosaurs moved in their natural habitats.

Two track sites featured in the new study are particularly interesting as they feature numerous parallel trackways traveling in the same direction and at the same pace. This arrangement indicated that the animals might have been walking in coordinated groups.

The authors of the article made sure to be cautious about their conclusions. They did not make any claims about herd behavior being universal among Stegosaurus, but stated that recent discoveries refute the hypothesis about their strict solitary lifestyle.

A rethink of the “loner dinosaur” image

Over the years, the image of Stegosaurus as a solitary, unintelligent dinosaur became an established one in pop culture. In accordance with the description provided by the Natural History Museum and Encyclopedia Britannica, Stegosaurus is a large herbivorous dinosaur from the Late Jurassic period, 150 million years ago. The dinosaur measured up to 30 feet in length and defended itself using spikes found at the end of its tail, referred to as the “thagomizer.”

Scientists now argue that previous beliefs about stegosaurs might be based on speculation rather than facts supporting their solitariness. As more data becomes available and methods advance, researchers have found themselves reviewing some previously accepted theories about the ancient species they study.

This year's study clearly demonstrates how much information about an animal can be contained in simple factors like the direction of tracks, the distance between them, and the repetition of the same actions in one area. It should be mentioned, however, that environmental factors play an essential role in trackway formation, which is why the researchers were careful when drawing conclusions.

What scientists still do not know

Despite the new discoveries, a number of mysteries relating to the social structure of stegosaurs remain unanswered. Scientists cannot establish how these animals lived – as herding animals, families, or occasionally traveled together for migration and protection.

However, scientists cannot state that individuals of different ages had distinctive behaviors or created segregated societies at present, but further analysis of additional fossils might prove that such an assumption is true, despite the absence of convincing evidence now.

At any rate, the results obtained by researchers provide a better image of Stegosaurus in the wild. Rather than seeing the dinosaur as a slow creature moving around like a prehistoric machine, the scientific community starts considering it as a social one with its communication rules and behavioral characteristics.

It is essential to note that dinosaurs' behavior is recreated by experts based on scattered pieces of information; thus, each discovery provides one more clue to uncovering a mystery. In other words, the discovery proves the idea that a lonely stegosaurus might not be alone.