Rediscovering The Coelacanth: The 400 Million-Year-Old Prehistoric Fish We Thought Went Extinct

Published April 23, 2019
Published April 23, 2019

The massive coelacanth was thought to have died off over 60-million-years ago, but a 1938 South African discovery shocked the scientific world.

Coelacanth Preserved

Wikimedia Commons20th century scientists were shocked to discover that the prehistoric coelacanth still roamed the seas.

Scientists have long known that the coelacanth was swimming the seas when dinosaurs roamed, so they had written off the prehistoric species as extinct. The mysterious fish was in the company of brontosaurs and tyrannosaurs and had supposedly vanished off the face of the earth some 60 million years ago. Yet one December morning in 1938, a South African museum curator made an astonishing discovery.

The “most beautiful fish” she had ever seen. She had no idea she had stumbled across a living fossil.

Rediscovering The Ancient Coelacanth

Marjorie Courtenay-Latimer was just 24 years old when she made the discovery of a lifetime. One of the less glamorous parts of her job as curator of the East London museum in South Africa was to respond to any calls from fishermen who had caught something they deemed to be unusual, then go to the docks and inspect it.

Courtenay-Latimer received one such call from Captain Hendrik Goosen on Dec. 22, 1938, and quickly went down to go inspect it for herself. The young curator recalled how she immediately noted a fin that looked like a “beautiful china ornament” and then “picked away at the layer of slime to reveal the most beautiful fish I had ever seen.”

Coelacanth Specimen

Wikimedia CommonsThe coelacanth is immediately recognizable by its immense size and unique color.

In addition to its “iridescent silver-blue-green sheen,” the fish possessed several other unusual features including “four limb-like fins and a strange puppy-dog tail.”

Courtenay-Latimer quickly realized that the strange specimen merited further study. Her first obstacle, however, was to convince a cab driver to help her take the nearly five-foot-long fish back to the museum.

Even though she failed to find any matches for the fish in the museum’s reference books, and the museum’s chairman shrugged off her discovery as “nothing more than a rock cod,” Courtenay-Latimer remained convinced that there was something special about the fish she had found.

She decided to send off a sketch of the specimen to her friend J.L.B. Smith, a lecturer at Rhodes University as well as an amateur ichthyologist, a.k.a. fish scientist. Smith took one look at Courtenay-Latimer’s drawing and, as he later recalled, “a bomb seemed to burst in my brain.”

The mystery fish had finally been identified as none other than a coelacanth, the prehistoric creature thought to have gone extinct 60 million years ago.

The Ins And Outs Of A Coelacanth

In addition to the fact that it was thought to have been extinct for millennia, the coelacanth is unique for several other reasons. The four “limb-like fins” Courtenay-Latimer noted are actually “lobe fins” that act almost as legs for the fish and, according to National Geographic, “move in an alternating pattern, like a trotting horse.” Some scientists believe that the coelacanth is actually an important link between conventional fish and the first creatures that evolved into four-legged, land and sea dwelling amphibians.

Exploring the habitat of the dino-fish, the coelacanth.

The coelacanth also has a distinctive joint in its head that allows it to widen its mouth an astonishing amount to swallow its prey. Of all living animals, the coelacanth is as yet the only known creature to possess this joint.

Its thick “pale mauvy blue” scales are also unique to other extinct marine animals. These strange fish also dwell at depths of up to 2,300 feet and use electricity generated from an electrosensory rostral organ in their snouts to navigate and hunt.

The coelacanth can grow to over six and a half feet in length and weigh up to 198 pounds. Further adding to their mystique, scientists have estimated that the fish can live to be over 60 years old.

Females are generally larger than males and though they are docile in larger groups, the coelacanth does not like physical contact. They’re nocturnal creatures, retiring to caves or deep waters during the daylight and then venturing to the lowest levels of the ocean to feed at the sea floor.

Ancient Coelacanth Fossil

Creative CommonsFor ichthyologsts, discovering a coelacanth was like discovering a living dinosaur.

The first coelacanth fossils date from around 400 million years ago, with the last dating from around 340 million years. This is why they had long been assumed to have been extinct. It is little wonder that after Courtenay-Latimer’s astounding 1938 discovery, the fish was often referred to as a “living fossil” and the event of its identification was deemed “the most important event in the study of natural history in the 20th century.”

Scientists dubbed the creature Latimeria chalumnae in honor of the museum curator who had discovered it and for the river in which it had been discovered.

Further Studies And Findings

Due to lack of a proper cold storage facility, Courtenay-Latimer was forced to have her specimen taxidermied, a process which lost the coelacanth’s internal organs. This made further studies nearly impossible.

It wasn’t until 1952 that another coelacanth was found in the Comoro Islands. Upon hearing the news, Courtenay-Latimer’s old colleague Dr. Smith flew immediately to the location where he “wept with joy when he found the bluish five-foot biological treasure still in good condition.”

Coelacanth Model

Wikimedia Commons

Over the next 23 years, a further 82 coelacanth would be found and mainly by accident. The species is actually useless to fishermen since their scales “ooze mucus” and the high amounts of oil, urea, and wax in their thick scales render them inedible.

For decades, the coelacanth was caught only in the Indian Ocean leading scientists to believe that they dwelled exclusively in that area until 1997 when ichthyologist Dr. Mark Erdmann made an unusual discovery on his honeymoon.

While strolling through an Indonesian fish market with his wife, Erdmann noticed a strange, enormous fish being carted around. The locals called it the raja laut, or the “King of the Sea” but Erdmann immediately recognized it as a coelacanth.

As Erdmann described, the chances of an ichthyologist stumbling upon an entirely new discovery on his vacation seemed “a bit too fortuitous to be real. I simply couldn’t believe that we were viewing something which was unknown to science.”

No coelacanth had ever been found outside of the Indian Ocean and so Erdmann passed up his chance and watched his priceless specimen be sold for a meager $12.

Coelacanth Full Color

Hoberman Collection/UIG via Getty ImagesThe coelacanth is considered to be the missing link between fish and tetrapods.

Luckily for Erdmann, an offer of a cash reward for this new Indonesian species of coelacanth bought him a second chance and this time with an actual living specimen. The scientist and his wife were able to take the “first ever photos of this species in life,” thus earning him his own place in the strange story of the coelacanth.

While the coelacanth is often referred to as a “living fossil,” this is a bit of a misnomer. The coelacanth does, in fact, evolve and adapt. Today, the coelacanth is considered critically endangered by the International Union for Conservation of Nature or IUCN. Their biggest risk is due to bycatch by fishermen, but because they’re bad eating, hopefully, more successful releases from accidental catch will keep the coelacanth swimming for another millennium to come.

Next, read about the fossil of the world’s oldest known animal. Then, discover a species of tortoise scientist also believed to be extinct

Gina Dimuro
Gina Dimuro is a New York-based writer and translator.