Protosalvinia is a prehistoric plant found commonly in shale from shoreline habitats of the Upper Devonian period.

Embedded in the tissues of the thallus are chambers in which spores (200 micrometre diameter) were produced by meiosis.

[6] Because Protosalvinia is usually preserved as a compression fossil, it can be difficult to determine whether its anatomy is more like a plant or an alga.

[7] Lignin and cutin have been found in the thalli, and sporopollenin in the spore walls.

[citation needed] However, the tips of Protosalvinia branches show evidence of conceptacle-like dips.