Coelacanth Day

What Is Coelacanth Day?

December 20 is "Coelacanth Day" in Japan. On this date in 1952, a coelacanth was caught off Anjouan in the Comoro Islands and examined scientifically. Known only from fossils until a living one turned up in 1938, the coelacanth finally became the subject of a proper scientific study on this day.

A Study Fourteen Years in the Making

The first specimen had in fact turned up earlier, but it was in no condition to be examined.

• First find: December 22, 1938, in South Africa
• What went wrong: decay had set in, so no adequate scientific study was possible
• December 20, 1952: a specimen was caught at Anjouan in the Comoros and examined scientifically
• The assumption before 1938: the group was believed to have died out at the end of the Cretaceous, about 66 million years ago

Why It Is Called a "Living Fossil"

The coelacanth survived into the present looking much as it does in the fossil record, which is why it is called a living fossil. Specimens and frozen individuals are occasionally displayed at Japanese aquariums, and it is one of those creatures whose name almost everyone knows even without having seen one.

Tips for Marking This Day

• Find a museum or aquarium that displays a coelacanth specimen
• Think of other creatures called "living fossils"
• Read up on the two discoveries of 1938 and 1952
• Open an illustrated encyclopedia to the coelacanth page with your kids

A Fish That Was Supposed to Be Extinct

A creature thought to have vanished at the end of the Cretaceous turned out to be swimming still. Coelacanth Day is a reminder of how satisfying it is when settled knowledge gets overturned.