Just when it seemed Florida’s ecosystems had been mapped from swamp to sky, a 15-million-year-old surprise turns the story upside-down: prehistoric tegus were prowling the region long before modern pets escaped their owners’ cages. A half-inch-long vertebra, tucked away in a museum drawer for two decades, has rewritten the tegu timeline.
The bone emerged from a clay mine just north of Florida’s border, unearthed in the early 2000s amid a frantic push to clear fossils before the quarry was filled in. It didn’t look like anything familiar – snake, lizard, something else entirely? After years of staring at mystery boxes, museum preparator Jason Bourque traced its shape back to the tegu family, the same chunky South American lizards now wreaking havoc in the Everglades.
Proving it took more than a sharp eye. A CT scan revealed every ridge and furrow, then an AI-driven pipeline compared those contours against more than a hundred 3D vertebrae from the museum’s openVertebrate database. The match was undeniable: this fossil belonged to a tegu. Yet subtle differences meant it couldn’t be pinned to any living species. The team christened the newcomer Wautaugategu formidus, nodding to the ancient Wautauga forest near its resting place and the Latin for “warm,” alluding to the Middle Miocene Climatic Optimum that let these lizards drift or swim northward.
That ancient warm spell made Florida’s coastline stretch far inland, creating a corridor for South American arrivals. As the planet cooled and sea levels dropped, these early intruders vanished, likely thwarted by egg-hatching temperatures too low for survival. Fast-forward to today’s invasive tegus, and it turns out they’re just a modern echo of a much older migration, one driven by global warming rather than pet releases.
With more fossil sites hiding beneath the Panhandle’s ancient shoreline, the hunt is on for additional clues. Meanwhile, the success of 3D modeling and machine learning hints at a future where countless unidentified bones could be sorted in hours instead of years. Florida’s fossil record might soon burst open, telling stories that have waited in dusty museum drawers for far too long.
The study has been published in the Journal of Paleontology
Source: Florida Museum
