US Customs and Border Protection agents made a major aquatic discovery while conducting routine screenings on international baggage at the Detroit Metropolitan Airport last week.

CBP agriculture specialists were x-raying bags re-entering the US after being separated from their owners when they found what was determined to be a juvenile dolphin skull, according to a news release.

The smuggling of certain wildlife, including marine mammals, and products made from them, «are subject to restrictions, prohibitions, import and export permits or certificates, as well as other requirements,» according to CBP.

«Possession of wildlife items, especially protected animals, is prohibited,» area port director Robert Larkin said. «We take wildlife smuggling seriously and work closely with our federal partners at the US Fish and Wildlife Service.»

The US Fish and Wildlife Service took the skull for further investigation.

CBP encourages travelers to stay informed about regulations before attempting to smuggle wildlife items into the US «to avoid penalties, seizures, and even arrest.»

It is not known at this time who owns the bag and if he will face any charges.