Comparing Neuropteris and Pecopteris Fossil Leaves and Their Trees, Medullosa and Psaronius

Neuropteris Fossil Leaf Imprint

Extinct Neuopteris leaves are associated with the seed fern tree called Medullosa, an ancestor of the flowering plant group. They flourished during the hot swamps of the Carboniferous through the Permian time slots about 360 to 250 million years ago. When Earth’s climate turned colder, it contributed to their final disappearance.

One way to tell the difference between Neuropteris and Pecopteris leaf fossil imprints is by examining the mid-vein of their leaflets. In Neuropteris, the vein stops midway up the leaflet and splits into several fine veins, whereas the mid-vein in Pecopteris extends up to the tip. Neuropteris leaflets are more blunt tipped and attach by a single stem as opposed by the entire base, as with Pecopteris. Also, Neuropteris has an overall heart shape.


Kingdom: Plantae

Division: Tracheophyta (vascular plants with system of transporting nutrients and liquids)

Class: Gymnosperm (means bare seeds – today’s examples i.e. conifers, cyads, ginkgo)

Order: Pteridospermales (extinct group of seed ferns which bore seeds on leaves)

Family: Medullosales (plants with complex pollen organs and large fronds)

Genera: Neuropteris (given name of foliage)

Prehistoric Medullosa Seed Fern Tree Rendition Drawing

Medullosa Seed Fern tree associated with Neuropteris was a medium sized, seed fern tree reaching about 33 feet (10 meters) tall. It really was not a true fern because it produced seeds, instead of spores. It only resembled fern trees and grew during the same era as the true fern trees, for example, Psaronius associated with the Pecopteris leaves. The leaves of Medullosa had many leaflets attached to a stem and could grow quite large, as much as 10 feet (3 meters) long.


Kingdom: Plantae

Clade: Traceophytes (Large group of vascular plants with transport system for nutrients and fluids)

Division: Pteridosperm(aphyta) (Extinct group of seed bearing plants)

Order: Medullosales ((plants with complex pollen organs and large fronds)

Family: Neurodontopteridaceae (Neuropteris Leaf)

Genus: Medullosa

Explanation of Pecopteris on following page . . .