Miscalibrated Internet Receptor Stalks
Miscalibrated Internet Receptor Stalks
Illustration for article titled What the fossil? _Diskagma buttonii_ edition

See this thing that is about half a millimeter in length? It's interpreted as a fossil from a terrestrial rock deposit in modern South Africa. From about 2.2 billion years ago. And the people who are describing it have no idea what the fossil it is.

Now obviously life is older than 2 billion years old, and even life on land has been shown to be around at this time (estimates of 2.8 billion years ago, at least). But 2.2 billion years ago is older than we suspect eukaryotic life (plants, fungi, animals, and anything else more 'complicated' than a bacteria) has been around (though not by much), and this thing looks too complex to be a bacterium.

Interestingly, the paper discussing this newly named fossil, Diskagma buttonii, also discusses an even older possible eukaryotic terrestrial fossil, Thucomyces lichenoides. Thucomyces is about 2.8 billion years old and was identified (as the name implies) as a lichen. ...even though it is way older than any fungus known, and "fungus" was as specific as the researchers were in guessing what kind of fungus the lichen was a symbiosis of.


So what is it?
Option 1: it's a bacterium that made a really elaborate fossil
Option 2: it's a fungus

If option 2 is correct, then fungi might have evolved on land instead of in the oceans, which seems to be the opposite of what both plants and animals did.

Retallack et al. 2013. Problematic urn-shaped fossils from a Paleoproterozoic (2.2 Ga) paleosol in South Africa. Precambrian Research 235:71-87.

Share This Story

Get our newsletter