From the depths of the Atlantic, researchers have brought back 57 animal species that were still unknown to science.
It all began in 2025, off the coast of Argentina. The research vessel Falkor (too) explored the Mar del Plata submarine canyon, an immense valley carved into the ocean floor. Its SuBastian robot descended several thousand meters and filmed a world populated by corals, crustaceans, and animals with astonishing forms.
This deep-sea sea cucumber was named “Loki” because of its prominent horn-like appendages, which evoke the god of Norse mythology.
Captured on video and in high-definition in situ images on the seafloor of the Mar del Plata submarine canyon, it is one of ten newly discovered sea cucumber species.
The images had already attracted millions of curious viewers when they were broadcast live. But the scientists also brought back specimens for examination. Seeing a strange animal is not enough to know whether it belongs to a new species: its anatomy must be compared with that of species already described.
In July 2026, around twenty specialists gathered in Buenos Aires for two weeks to analyze these samples. Their work made it possible to recognize 57 species new to science, as well as five new genera. The specimens came mainly from the Mar del Plata expedition, along with other Argentine collections.
Among the discoveries is a remarkable sea cucumber nicknamed “Loki.” It bears little resemblance to the vegetable it is named after: it is a soft-bodied marine animal with appendages resembling small horns. It was observed at a depth of 2,577 m, where sunlight can no longer reach.
The Falkor (too) oceanographic vessel of the Schmidt Ocean Institute, used to explore the Mar del Plata submarine canyon, off the coast of Argentina.
Photo: United States Embassy in Argentina, CC BY 4.0, Wikimedia Commons.
The researchers also identified 20 species of tiny crustaceans called copepods. Only a small portion of the samples from this group has been examined, and every specimen studied belonged to an unknown species. The team also identified 22 species of echinoderms, 14 species of corals and related animals, as well as one mollusk.
None of these discoveries have yet been officially described and named. To enter a species in scientific catalogs, researchers must publish a description that distinguishes it from others. Some identifications will require further genetic analyses. The figures announced therefore correspond to the identification work already completed.
These animals live in a region where warm and cold ocean currents meet. The mixture supports abundant life even in the depths. At Mar del Plata, the canyon exceeds 3,500 m, but only a small part of its habitats has been explored.
A new expedition is planned between February and March 2027, this time in another Argentine submarine canyon. The researchers hope to encounter animals related to those from Mar del Plata, but also to discover how many other species remain hidden at the bottom of the Atlantic.