Ancient Forest Kept Good Company

When hundreds of 390-million-year-old fossil tree stumps were unearthed in a sandstone quarry near Gilboa, New York, in the 1920s, the site gained fame as the world's oldest forest. Scientists believed the location had been home to a single, enigmatic species of tree dubbed Eospermatopteris, and soon afterward, the quarry was closed and filled with rubble. But when researchers re-excavated the site in 2010 and power-washed about 1200 square meters of the thin mudstone layer that held the fossils, they identified the remains of two other types of plants that had grown in the ancient swamp (artist's reconstruction in main image). New members of the forest include a tree-sized type of club moss—with an 11-centimeter-diameter trunk and a height of at least 3.9 meters, the tallest known from this era—and a vinelike plant whose multibranched stems grew from woody roots (inset; arrow denotes root fragment). The vinelike plant, previously known only from small fragments found elsewhere, probably couldn't stand well on its own and either climbed or leaned against other tall plants in the forest for support, the researchers report online today in Nature. The new finds, say experts, are the first direct evidence that some early forests contained widely divergent types of intermingling plants and weren't just groupings of single-species patches.