Paleontologists digging in western Wyoming made a discovery so rare that researchers are calling it an extraordinary window into a world that vanished tens of millions of years ago. Field crews unearthed four ancient snake fossils so remarkably well preserved that their skulls, ribs, and tails were still arranged in near-perfect anatomical order, a condition that is almost unheard of for fossils of this age and one that sent the research team into immediate excitement. The snakes, which belong to a newly identified species now named Hibernophis breithaupti, were found curled together inside what appears to be an underground burrow, sealed and preserved in extraordinary detail by volcanic ash that blanketed the area and locked the chamber shut before the bones could scatter or decay. Finding a single complete snake skeleton is already considered extraordinarily lucky in paleontology, so finding four intact specimens intertwined in the same spot left researchers genuinely speechless.
The discovery reshapes what scientists understand about the early evolution of boas and pythons, whose North American origins have long been poorly documented and difficult to trace. But the detail that has captivated researchers most is not the anatomy at all, it is the way the snakes were found: huddled together in a shared winter shelter, which is precisely what modern garter snakes still do today when temperatures drop and they need to pool body heat to survive. The leading paleontologist on the project described it as fascinating to find possible evidence of that social behavior stretching back 34 million years, noting that communal hibernation is virtually unique to snakes among the world’s nearly 15,000 living reptile species. The fossils represent the oldest known evidence of this behavior anywhere in the snake fossil record and suggest that the social survival instincts of modern snakes have roots far deeper than anyone had previously suspected.
