British marine biologists have found what may be the oldest living animal — that is, until they killed it.

The team from Bangor University in Wales was dredging the waters north of Iceland as part of routine research when the unfortunate specimen, belonging to the clam species Arctica islandica, commonly known as the ocean quahog, was hauled up from waters 250 feet deep.

Only after researchers cut through its shell, which made it more of an ex-clam, and counted its growth rings did they realize how old it had been — between 405 and 410 years old.

Another clam of the same species had been verified at 220 years old, and a third may have lived 374 years. But this most recent clam was the oldest yet.

"Its death is an unfortunate aspect of this work, but we hope to derive lots of information from it," postdoctoral scientist Al Wanamaker told London's Guardian newspaper. "For our work, it's a bonus, but it wasn't good for this particular animal."