The Fern Prarie: fact or myth? (Patreon)

Moschorhinus and Lystrosaurus by DiBgd. Notably, the small plants in this picture are not true ferns but the extinct seed fern Dicrodium. To help illustrate my point.

In paleoart, “fern praries” are a type of biome frequently depicted. After all, if there was no grass in the Mesozoic (until the very end, at least), what else carpetted the ground?

A lot, actually. Seed-ferns, horsetails, moss…

The idea that ferns specifically formed the Jurassic savannas is not without merit. Modern ferns are the most common carpetting plants after grass, dominating forest undergrowth and even forming small plains in clearings. Some species can live in desert environments, so even places with little moisture could hypothetically boast seasonal fern steppes.

But the thing is, why ferns when there were so many other plant groups that could fill the grass niche? Notably, seed-ferns and small gymnosperms would be equally if not more fitting in more arid conditions. Perhaps some areas were carpetted by herb-like early angiosperms, not quite grass but almost there.

Remember that most fossil assemblages are biased towards riparian environments, where ferns surely excell. But there is little evidence for small flora in drier pre-Cenozoic environments, and as such the fern prairie must be questioned as an environment. It most likely existed, but I doubt it dominated the Mesozoic open spaces.