Golden Tree Coral Gets Its Own New Family

Five hundred metres beneath the Pacific, on a rocky slope off Costa Rica, researchers have found something no one has ever seen before: a bright yellow, tree-like coral so genetically strange that it could not fit into any known family. Scientists have now given the golden tree coral its own brand-new family on the tree of life, a rare move that underlines just how little we know about the deep ocean. They also gave it a name straight out of fantasy literature, inspired by J.R.R. Tolkien's Elvish language.

The newly named species is called Laurinque elenya, described in the open-access journal ZooKeys this year by a team led by Dr Odalisca Breedy of the Universidad de Costa Rica, as reported by Newswise. The golden tree coral grows in branching colonies on seamounts near Isla del Coco and along Costa Rica's Pacific margin, at depths between 360 and 529 metres, far below the reach of sunlight. Colonies can stand over a metre tall, rising above rocky outcrops almost entirely blanketed by brittle stars, creating what researchers describe as a shimmering, star-strewn seafloor.

Too strange for any known family

Figuring out where the golden tree coral belonged turned out to be unusually difficult. The team first sequenced three genes that coral scientists commonly use for identification, and each gene pointed to a completely different, unrelated family. That level of disagreement is highly unusual, and it meant the golden tree coral matched nothing in the scientific record.

To settle the question, the researchers turned to phylogenomics, comparing hundreds of genes at once instead of just a few. The full genetic picture revealed that the golden tree coral represents a unique evolutionary lineage, most closely related to an existing family called Eunicellidae, but distinct enough in both its genes and its anatomy to need a family of its own: Laurinqueidae. Alongside the new family came a new genus, Laurinque, and the new species elenya. Scientists almost never get to name one of those in a career, let alone all three at once, according to the study published in ZooKeys.

Breedy first spotted the octocoral garden in 2019, during an expedition aboard a Schmidt Ocean Institute research vessel, and was struck by the beauty of the landscape, which later inspired the fantasy-themed naming. Samples were collected in 2019 and again in 2023 using the remotely operated vehicle SuBastian, aboard the vessels Falkor and Falkor (too). The project was supported by the Schmidt Ocean Institute and a National Geographic Society research grant, with collaborators from Costa Rica and the United States working out the molecular analysis.

A Tolkien name for a deep-sea forest

The naming of the golden tree coral is half the story. The genus name Laurinque comes from "Laurinquë," the Quenya word for "golden tree," chosen for the colonies' vivid yellow coloration and tree-like shape. The species name elenya means "stellar" or "of the stars" in the same constructed Elvish language, a nod to the dense fields of brittle stars carpeting the seafloor around the coral. Together, the pairing evokes what the researchers likened to a mystical Elvish landscape, hidden hundreds of metres below the waves.

That playful choice lands at a moment when ocean discoveries are having a minor renaissance. Costa Rica's seamounts keep turning up undocumented species, from new octopuses to deep-sea sharks, and this golden tree coral adds to a growing list that shows how much of the planet's largest habitat remains unmapped. If you want another taste of that world, check out this site's coverage of the dozens of new deep-sea species found off Argentina, another recent reminder that the ocean floor still surprises us.

The deep ocean covers roughly two-thirds of Earth's surface, yet scientists estimate that the vast majority of it has never been directly observed. Coral gardens like the one this golden tree coral forms are considered vulnerable marine ecosystems, because their complex branching structures provide shelter and feeding grounds for a wide range of other deep-sea life. Discoveries like this one strengthen the case for protecting seamounts, which face growing pressure from deep-sea mining proposals and bottom trawling.

For anyone who grew up on fantasy novels, the real wonder might be the overlap: a creature from the deep sea, glowing yellow in the dark, named in a language invented for elves. The golden tree coral waited millions of years in the dark to be found. It was worth the wait. Find more science stories like this on our Science topic page.