Tetrapods, the first four-legged land animals, have also been considered the first organisms that had fingers and toes but researchers at Uppsala University say that is not the case.
Using medical x-rays, they found rudiments of fingers in the fins in fossil Panderichthys, the “transitional animal,” which indicates that rudimentary fingers developed considerably earlier than was previously thought.
Our fish ancestors evolved into the first four-legged animals, tetrapods, 380 million years ago. They are the forerunners of all birds, mammals, crustaceans, and batrachians (Editor - and reptiles! We have the most eagle-eyed readers anywhere.) Since limbs and their fingers are so important to evolution, researchers have long wondered whether they appeared for the first time in tetrapods or whether they had evolved from elements that already existed in their fish ancestors.