Scientists have figured out what that massive 50-foot carcass found on an Indonesian beach is, and it’s not a giant squid, as local sources were originally reporting. Instead, it’s almost certainly a baleen whale based on the skeleton and the presence of baleen, a filter feeder mouth system, on the carcass.

The Jakarta Post initially reported that it was a dead giant squid, but at 50 feet in length, that’s a little big even for a giant squid. The body was found on Seram, the largest island in the Maluku Island group, which is near a common migration route for baleen whales.

While dead whales will usually sink to the bottom of the ocean, creating temporary ecosystems on the ocean floor as scavengers pick it clean, this whale may have had a bacterial infection that caused it to produce gases that resulted in it staying afloat..