A fascinating Canadian fossil described as “an evolutionary link missing from the fish transition to tetrapods” reveals an ancient fish species with the bones of its arms, hands and fingers, similar to ours, wrapped in fins. The 157-centimetre (61.8-inch) specimen, discovered about 10 years ago in The Miguhasa National Park in southeastern Canada, dates back between 393 and 359 million years ago, a period known as the late mud basin, in which some fish began to try to get out of the water.
These adventurous little guys eventually evolved into a whole family of tetrapods or tetrapods, including dinosaurs, reptiles, birds, amphibians, whales, dolphins, seals, turtles and mammals – including humans. Leaving the water is one of the most profound and mysterious evolutionary leaps in history, and in addition to developing a method of breathing dry oxygen, the fish find it difficult to support their weight and move on land. That is, until some of these fish begin to evolve the basic arm.
This Canadian fossil shows that the tibia, tibia, ruler, wrist bone and finger bone of the wrist all appear during this time, and the fish that were lucky enough to accept the variation were much easier to move around without the buoyancy of water. Before fish leave the surface, vertebrate hands develop deeply in evolution. This is a true transitional fossil, an intermediate between fish and tetrapods. The study was published in the journal Nature.