Fossil Fern | Laveineopteris rarinervis | Illinois

Laveineopteris rarinervis Pennsylvanian Carbondale Formation Coal City, Illinois Specimen approx. size: 2.625" x 1.25" Matrix approx. size: 3.375" x 1.25" Laveineopteris rarinervis is a classic and beautifully recognizable Late Carboniferous seed fern (Pteridosperm) commonly found in Pennsylvanian-aged strata of Europe and North America. Laveineopteris rarinervis is a pinnate seed fern characterized by its large, delicate fronds composed of slender rachises and distinctly shaped pinnules. Individual pinnules are typically elongate-ovate to lanceolate, with a softly tapered tip and a broad attachment to the rachis. The venation is the most diagnostic feature: a strong, central midvein runs the length of each pinnule, from which numerous fine lateral veins emerge at a sharp angle before gently curving toward the margin. These lateral veins are closely spaced and give the fossil its characteristic “feathered” texture.