For millions of years, Tany laid buried under layers of rock in what is now Hudson County. She was unearthed in 1979 by a trio of amateur fossil hunters in an abandoned quarry: a rare, complete skeleton of a primitive reptile — one that swam through waterways in the northeast as dinosaurs began to roam the planet. But in the decades since her discovery, Tany has been stored out of state, modestly displayed in the lobby of a New York research laboratory. Now, she’s back home. The fossil’s founders, Steven and Trini Stelz and James Leonard, recently donated the 200-million-year-old...