Lichens, comprising symbiotic fungi and algae (and/or cyanobacteria), are crucial ecological components that inhabit various substrates, including fossils. A recent study highlights their role as biological indicators of fossils in western North America, and demonstrates that they can be identified through remote sensing techniques.
Preferential colonization of dinosaur bones by lichens. Image credit: Pickles et al., doi: 10.1016/j.cub.2025.09.036.
Dr. Brian Pickles from the University of Reading noted, “This research showcases how extant organisms can assist in uncovering ancient life forms.”
“It’s fascinating to realize that these lichens, which essentially represent miniature ecosystems, thrive on the remains of dinosaurs that went extinct over 75 million years ago.”
“Utilizing drone technology to identify spectral signatures in lichens could transform how paleontologists search for fossils.”
In their research, Dr. Pickles and his team identified two lichen species, Rusabschia elegans and Xanthomendoza trachyphylla, which colonized 50% of exposed fossil bones while affecting less than 1% of nearby rock fragments.
This preference can be attributed to the alkaline, calcareous, and porous nature of dinosaur bones that these lichens favor.
“Although the tendency of lichens to thrive on fossil bones has been observed for decades, it has never been quantitatively assessed until now,” stated Dr. Caleb Brown, a researcher at the Royal Tyrrell Museum of Paleontology.
“During our first encounter with a high concentration of exposed fossil bone, such as in a bone bed, our attention often shifts from the bones themselves to the vibrant orange lichen ‘meadows.’
The researchers deployed a drone fitted with specialized sensors to pinpoint lichen-colonized fossils from aerial imagery boasting a resolution of 2.5 cm.
Lichens reveal distinct spectral characteristics, exhibiting lower reflectance in blue wavelengths and increased reflectance in the infrared spectrum.
This innovative method presents considerable benefits for exploration in paleontology, particularly in remote locations where conventional ground surveys are challenging.
This strategy could expedite fossil discoveries while minimizing field expenses and ecological impacts.
The findings are rooted in decades of anecdotal observations made by paleontologists.
In 1980, paleontologist Darren H. Tanke observed that the orange pigmentation of lichens on centrosaurus bones might soon be detectable via satellite. The potential for locating bones using aerial drone technology appears more achievable than ever.
“This drone study sets the foundation for employing aircraft and satellites to map larger expanses,” remarked Dr. Derek Peddle, a researcher at the University of Lethbridge.
“Our newly developed lichen index will aid in fossil identification across vast terrains.”
“It’s exhilarating to merge our imaging technology with the expertise of this international team to enhance dinosaur discovery through remote sensing of lichens.”
The team’s publication appears in this week’s issue of Current Biology.
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Brian J. Pickles et al., 2025. Remote sensing of lichens by drone to detect dinosaur bones. Current Biology 35 (21): R1044-R1045; doi: 10.1016/j.cub.2025.09.036
Source: www.sci.news
