At least two vibrant, colorful lichen species have specialized to colonize on exposed dinosaur bones

Amazing stuff!

"... Now, paleontologists and remote sensing scientists working in Dinosaur Provincial Park in Alberta, Canada have identified an unlikely—and vibrantly colored—ally. 

For decades, researchers have noted anecdotally that bright orange lichens tend to grow on exposed dinosaur bones, serving as a kind of beacon for fossil hunters. ... Back in 1980, paleontologist Darren H. Tanke even speculated that lichen growing on bones belonging to Centrosaurus might be detectable by satellites.

The study authors found that two lichen species—Rusavskia elegans and Xanthomendoza trachyphylla—colonized as much as 50% of exposed fossil bones but left the surrounding rock fragments alone. Dinosaur bones, the team reports, likely provide the alkaline, calcium-rich, and porous substrates these species need to thrive in semi-arid environments like the Canadian Badlands. These lichen-covered fossils create distinctive spectral signatures, which can be detected from 30 meters above the ground using specialized drones. ..."

From the abstract:

"Advances in palaeontology and evolutionary biology are often linked to the discovery of new fossils, yet these discoveries are typically serendipitous.

Here, we report that lichens can serve as biological indicators of vertebrate fossils in western North America and can be identified using remote sensing. Lichens are symbioses between fungi and algae (and/or cyanobacteria) that play important ecological roles and colonise many substrates, including fossils. Preferential colonisation of dinosaur bones by lichen with vibrant orange pigmentation (Figure 1A,B) has been recognised anecdotally for decades (Darren H. Tanke, personal communication).

We found that the spectral reflectance profiles of these lichen pigments and the preferential association between modern lichens and ancient bones can be used to detect dinosaur fossils by remote sensing, for which we propose new spectral indices."

ScienceAdviser

Lichens and drones reveal dinosaur bones (open access)

Orange marks the bone.

Figure 1 Preferential colonisation of dinosaur bones by lichens with distinctive spectral profiles and their detection in drone (RPAS) images.