Neuropteris sp.

A coal mine drill core can bring up more than rock. Sometimes, it reveals a beautifully preserved fragment of an ancient forest.

This Carboniferous fossil is tentatively identified as Neuropteris sp.—the “sp.” means the species is undetermined. Its rounded, tongue-shaped leaflets, called pinnules, preserve delicate veins branching towards their edges.

Despite its fern-like appearance, Neuropteris belonged to an extinct group of seed plants commonly called seed ferns. These plants reproduced using seeds rather than spores. 

Each pinnule was just one part of a much larger, divided leaf, and some related plants carried foliage several metres long.

What might we have seen growing around it?

Carboniferous Tropical Coal Forest

In a typical late Carboniferous tropical coal forest, towering clubmoss relatives such as Lepidodendron rose above the wetlands. 

Their trunks bore distinctive leaf scars, giving them a patterned, almost reptilian appearance. 

Nearby, Calamites—tree-sized relatives of today’s horsetails—grew along wet ground and waterways. 

Tree ferns spread their crowns above an undergrowth of smaller ferns and other spore-bearing plants, while seed ferns added their own sweeping greenery. The exact mix changed with the habitat and through time.

There was movement among those plants, too. Amphibians inhabited Carboniferous waterways and their margins, and early reptiles were beginning their story on land. 

Over more open wetlands, dragonfly-like insects called griffinflies hunted on the wing. Some were giants compared with most insects we see today; their broad wings probably suited open spaces better than crowded forest interiors. These are possible neighbours in the wider Carboniferous world, rather than animals we can place beside this particular leaf without knowing its locality and age more precisely.

In waterlogged parts of these landscapes, dead vegetation accumulated as peat. Burial, heat and time eventually transformed many of those deposits into coal—the reason a drill would one day pass through this ancient world.

Now, framed by a circle of stone, this small piece of Neuropteris lets us trace the delicate architecture of a leaf from a forest that flourished long before the first dinosaurs.

Further reading: Sam Noble Museum: Fossil Medullosans; British Geological Survey: Plants; Oxford University Museum of Natural History: The Carboniferous; Natural History Museum: Griffinflies.