Three extinct species, St. Clair Pennsylvania Fern Fossils, Carboniferous Period For Sale

This coal-age fern fossil sample was found near St Clair, Pennsylvania which is world-famous for producing such fossils with striking “white-on-black” color contrast contains four different species (Alethopteris, Neuropteris, Pecopteris and Calamites). The branching Calamites sets this specimen apart. The site has since been closed to further collecting.

These extinct prehistoric fossil “seed ferns” developed in the Carboniferous period (around 300-360 million years ago). Although they resembled modern ferns, they instead reproduced by means of seeds. Seed ferns eventually went extinct around 73 million years ago, while dinosaurs were still around. Fossils from St Clair, PA specifically date to the Llewellyn Formation (300-308 million). These fossil ferns are about the same age as those also found in the famous Mazon Creek formation in Illinois. One century can seem so hard to comprehend, yet these ferns thrived 3 million times that long ago.

Believe it or not, these colors are fully natural! These ancient plants fell into a swampy bog where a low temperature, low pressure, and oxygen-depleted environment evolved the plant tissue into pyrite, which was later replaced with pyrophyllite (aluminum silicate) creating the bold white color contrasting with the black shale. Sometimes orange-brown coloration comes from iron. Completely natural ! No repair or restoration. No paint or touch up. Nature and time are the artists. Quite striking !

You get the fossil fern frond leaf plate shown. Has fossils on both sides. Larger specimen grade A+. Nice display piece. Unique holiday gift ! See photos