A chunk of rock that provided 19th-century palaeontologists with a first glimpse of dinosaur skin has yielded further insights, thanks to modern imaging technology.
A study published in Communications Biology has used laser imaging to reveal fine scales and “goosebump-like structures” called papillae on dinosaur skin preserved on the rock’s surface.
The rock sample was discovered in England in 1852 next to the bones of a sauropod called Haestosaurus becklesii. The papillae, which have also been observed in other sauropod species, would reportedly have given the skin a “fine bumpy texture”.
“The papillae are not seen in the skin of other types of dinosaurs, so the question becomes: why are they present in sauropods?” said Nathan Enriquez, a PhD student from the University of New England in Australia who co-led the study.
The scientists have at least one plausible explanation: the ‘goosebumps’ may have helped the large, long-necked sauropods regulate their body heat, by increasing their surface area.
“When you’re as large as a sauropod – which can exceed 30 metres in length and 50 tonnes in mass – overheating becomes a real concern simply because you have a comparatively small surface area compared to your volume,” Enriquez said.
“Sauropods started getting really big in the Early Jurassic, which is about the same time that we predict these skin papillae evolved within this group. Perhaps, then, there may be a link between the emergence of these papillae and the evolution of huge sauropod body sizes.”
“We are looking forward to testing these ideas further,” he concluded.
The paper’s publication comes hot on the heels of another discovery led by Enriquez, of well-preserved dinosaur footprints on an exposed riverbank in Canada.