Beware of Tiny Pseudofossils

A new study warns that teeny tiny fossils may, in many cases, turn out to be only pseudofossils—shaped like the remains of dead critters, but really just lumps of stuff that happen to have those shapes.

This warning echoes the lesson people draw from the Ig Nobel Prize-winning work of Chonosuke Okamura, who published extensive reports about what he called “mini-species”—mini-dinosaurs, mini-princesses, and much more.

The new paper is: “Organic Biomorphs May Be Better Preserved than Microorganisms in Early Earth Sediments,” Christine Nims, Julia Lafond, Julien Alleon, Alexis S. Templeton, and Julie Cosmidis, Geology, epub 2021. The authors, at Pennsylvania State University, the University of Colorado, and Université de Lausanne, Switzerland, explain:

Organic biomorphs that form via the abiogenic reaction of sulfide with organics are likely to be preserved as pseudofossils in cherts through rapid silica encrustation and, possibly, organic-matter sulfurization. In addition to their striking morphological resemblance to putative Precambrian microfossils, these pseudofossils would share chemical characteristics with actual fossil bacteria, such as complex organic compositions and presence of nitrogen atoms. Importantly, organic biomorphs demonstrate better morphological preservation compared with microbial cells during silicification.

While these findings do not refute previous interpretations of Precambrian putative microfossils, our results call for a circumspect approach when evaluating the biogenicity of chert-hosted organic microstructures.

Carolyn Gramling wrote a report, called “Many Early Fossils May Be Imposters“, about that report, in the February 27, 2021 issue of Science News.

Okamura and the Mini People

The 1996 Ig Nobel Prize for biodiversity was awarded to Chonosuke Okamura of the Okamura Fossil Laboratory in Nagoya, Japan, for discovering the fossils of dinosaurs, horses, dragons, princesses, and more than 1000 other extinct “mini-species,” each of which is less than 1/100 of an inch in length.

Okamura documented his discoveries in a series of books called “Reports of the Okamura Fossil Laboratory,” published by the Okamura Fossil Laboratory in Nagoya, Japan during the 1970’s and 1980’s.