Since there's a lot of love for all things algal right now...
A chunk of Jurassic stromatolite, a structure formed by repeated layers of sediment and microbial mats (often cyanobacteria), making a blobby hummock.
These guys have been doing their thing for 3.5 billion years.
#FossilFriday
⚒️🌍🟢🔬🧪
