How do the principal megabiases in the fossil record affect the discovery of past bryophyte diversity?

The bryophyte fossil record is less abundant and diverse than predicted by the age of the group and as compared to the fossil record of younger plant groups. Taphonomic biases explain only partially its scarcity. Here, we investigate whether and how recently recognized megabiases that have the potential to affect the fossil record, in general, determine the structure of the bryophyte fossil record.

We update the pre-Miocene bryophyte fossil record with an ~30 % increase since its latest review (in 2018) and examine fossil bryophyte diversity against the temporal and spatial distribution of the rock record, and economic geography, to document patterns in potential presence, discovery and study of bryophyte fossils.

Fossil bryophyte abundance is not correlated with the area of rocks exposed around the planet for different geological ages. More fossil bryophytes are known from younger rocks due to the overall richer fossil content of those rocks. More fossil bryophytes have been documented from the Northern Hemisphere, from developed countries, from countries where English is the official language and from countries where more specialists are exploring the fossil record.

The discovery and documentation of bryophyte fossils are biased by socio-economic and language factors, which affect significantly the structure of the fossil record of the group, at least in terms of taxonomic diversity. 'Parachute science' did not and does not significantly influence the documentation of fossil bryophytes.