Fossilised skin from sauropod dinosaurs, possibly Diplodocus, reveals structures suggesting they could have been as vibrant as modern birds. Researchers at the University of Bristol examined 145-million-year-old samples from Montana using electron microscopy. The findings indicate diverse melanosomes that point to potential for varied shades and patterns.
Scientists have uncovered evidence that long-necked sauropod dinosaurs, such as Diplodocus, might have sported colorful skin rather than the drab hues often depicted in traditional illustrations. Tess Gallagher and her team at the University of Bristol, UK, analyzed skin fossils dating back about 145 million years. These specimens were collected in 2019 and 2022 from the Mother’s Day Quarry in Montana.
The fossils, consisting of four scales, were not definitively identified but are believed to belong to a sauropod like Diplodocus. Using a scalpel, the researchers removed tiny pieces and examined them under a scanning electron microscope, revealing three-dimensionally preserved skin at a cellular level. They discovered diverse melanosomes—organelles that store melanin and produce color in skin, hair, eyes, and feathers.
“I was expecting to find traces of melanin at the bare minimum,” Gallagher said. “What we did find was evidence that sauropods could have diverse melanosome shapes, which ultimately means the potential for diverse colours.” All studied specimens contained melanosomes in two primary forms: oblong and disc-shaped. While exact colors remain undetermined, the variety implies multiple possible shades.
The disc-shaped structures resemble platelet melanosomes in modern bird feathers, suggesting sauropods could have achieved striking patterns. “Diplodocus would have been remarkably textured animals, with potential colour patterning and diverse colours,” Gallagher noted. “These animals could have more striking colour patterns, as opposed to being grey like we see in old palaeoart.”
Mike Benton, a palaeontologist at the University of Bristol not involved in the study, described the structures as plausibly melanosomes. He called it a possible first record of color-bearing melanosomes in a sauropod dinosaur. The research appears in Royal Society Open Science (DOI: 10.1098/rsos.251232).
This discovery challenges assumptions about dinosaur appearances, highlighting how advanced microscopy can reveal hidden aspects of prehistoric life.