When staffers from the New York State Museum dug out two massive fossils from a Catskills quarry, they solved a 130-year-old mystery. The fossils—a frond-encircled treetop and a long, slender trunk—have also forced scientists to redraw their mid-Devonian (about 385 million years ago) landscapes to include tall trees.
The mystery was the identity of the Gilboa stumps—swollen tree-stump fossils discovered in the 1870s in the same New York county and named for the nearby town. Distinctive ridges at the base of the latest trunk fossil matched those on the old Gilboa stumps. Named Wattieza, the tree resembles modern-day palms and has usurped the conifer-like Archaeopteris as Earth’s oldest tree by some 25 million years, as reported last April in the journal Nature.
Given their abundance, the Gilboa stumps have long been thought to represent some kind of forest, an evolutionary first. Scientists imagined they were big, but not that big, says William Stein, paleobotanist at Binghamton University in upstate New York. At 26 feet, the fossilized trunk was three times taller than any known plant from the period. “We all have to be amazed with the scale of these things,” Stein says.
Size has not been the only surprise. The type of plant it was—more tree fern than conifer—forces a major rethinking of “how modern-scale forests actually came into being,” says Stein. “Here we have a plant that’s big and it’s producing a ton of [leaf] litter.” Dominant plants like Wattieza set the tone for an ecosystem during the Devonian period, which is when Earth’s modern ecology was formed, Stein says. “Wherever the plants go, the animals follow.”
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