SAN FRANCISCO (AP) — More than 80 years ago, a beautiful butterfly called Xerces Blue that once fluttered among San Francisco’s coastal dunes went extinct as stately homes, museums and parks ate up its habitat, marking the first butterfly species in the United States to disappear due to human development.

But thanks to years of research and modern technology a close relative of the shimmery iridescent butterfly species has been reintroduced to the dunes in Presidio National Park in San Francisco. Dozens of Silvery Blue butterflies — the closest living relatives of the Xerces Blue — were released in the restored habitat last week, officials said Monday.

Scientists with San Francisco’s California Academy of Sciences utilized the Academy’s genetic sequencing capabilities and analyzed Xerces Blue specimens in their vast collection to confirm a group of Silvery Blues in Monterey County, about 100 miles (160 kilometers) south of San Francisco, could successfully fill the ecological gap left by the Xerces Blue.