Its small body looked just as you’d expect for a newborn porpoise, but with one inescapable difference – two perfectly formed heads.

The two male calves, who shared one body, were the first reported case of conjoined twins in the harbour porpoise species. Sadly, the twins are thought to have died shortly after birth.

The discovery was reported in the latest issue of the Deinse journal from the Natural History Museum of Rotterdam.

The twins were pulled from the water by a team of fishermen working in the Southern North Sea in May 2017. Unfortunately, the crew thought it was illegal to keep the remains so threw the specimen back into the sea, but not before taking a series of photographs.

Conjoined twins are extremely rare in wild animals. As well as being the first recorded case of conjoined twins in their species, the twins are only the tenth known case in the entire whale and dolphin family. However, the true number of incidences is unknown, most likely due to high rates of prenatal and antenatal mortality.