New Jersey quarry holds one of the world's most detailed records of the asteroid event that ended the dinosaurs

A suburban New Jersey quarry, situated behind a Lowe's and a Chick-fil-A in Mantua Township, has emerged as one of the most significant paleontological sites in the world. Paleontologist Ken Lacovara — best known for discovering the Dreadnoughtus, a new dinosaur species, in 2004 — initially visited the site in 2003 as a low-stakes training ground for his university students. He has since described that first impression as badly mistaken.

Running across the quarry is a sediment layer that Lacovara describes as the most significant record to date of the hours immediately following the asteroid impact 66 million years ago. His team has recovered more than 100,000 fossils representing over 100 species, as well as iridium, a metal associated with asteroids, embedded in that layer.

Lacovara described a rapid sequence of events after the asteroid struck near the Yucatan Peninsula: a 10.3-magnitude earthquake crossing North America within minutes, a second seismic shock roughly 15 minutes later, and global temperatures rising to what he characterized as between "toaster oven and pizza oven" within the hour. Smaller mammals likely burrowed to escape the heat, while dinosaurs — having ruled Earth for approximately 165 million years — were, according to Lacovara, functionally extinct within that first hour. A subsequent 130-foot tsunami swept carcasses out to sea, where they sank to the ocean floor and formed the bonebed now being excavated.