Science News reports on a colorful breakthrough in dinosaur hunting, thanks to two lichen species that prefer to grow on dinosaur bones and are a shade of orange that’s bright enough to be spotted by drones flying overhead:
Lichens tend to be quite picky about where they grow, says AJ Deneka, a lichenologist at Carleton University in Ottawa, Canada, who was not involved with the research. Species that grow on granite do not grow on sandstone or limestone and species that grow on wood don’t grow on rock.
Dinosaur bones covered in lichen have long been known to paleontologists working in desert fossil hotspots of western North America. In 1922, paleontologists found an Ankylosaurus fossil covered in orange lichen in the Canadian badlands. In 1979, a similarly colored lichen was reported growing over a Centrosaurus bonebed in the same area. The orange-colored symbiote is often the first thing researchers notice when working in these regions, with the discovery of bone coming second.
By scrutinizing vibrantly colored lichen and where it grows in Dinosaur Provincial Park in Alberta, [University of Reading paleontologist Brian] Pickles and his colleagues found that two species of lichen, Rusavskia elegans and Xanthomendoza trachyphylla, had a strict preference for colonizing fossil bones and were almost entirely absent from surrounding ironstone rock.
…
Pickles and his colleagues next measured light frequencies reflected by the rock, bones and bone-inhabiting lichen and tested whether they could distinguish the lichen from these surroundings using drones. Spectral analyses found the lichen primarily reflected certain infrared light frequencies, which the researchers then used to develop drone sensors that could detect this light from above.
Using these drones, the researchers were able to identify fossil bonebeds from a height of 30 meters. “We could only locate the fossils thanks to the lichen association,” Pickles says.
—
You can read more of the lichen-drone-dinosaur-bone research here, in Current Biology.