A reptile from 247 million years ago revolutionizes our understanding of feather origins.
The evolution of skin and its appendages, such as scales, hair, or feathers, has been one of the most debated fields for years. An international team led by paleontologist Stephan Spiekman has found a crucial clue: fossil remains of a reptile called Mirasaura grauvogeli, which lived about 247 million years ago, and presents complex skin appendages.
The discovery suggests that the ability to generate complex skin appendages may have emerged in early reptiles and not exclusively in lineages leading to mammals or birds. The Mirasaura is one of the fossils that force us to reconsider how and when these particular skin adaptations developed.
Complex appendages in an unexpected lineage
The study, based on two well-preserved skeletons of Mirasaura grauvogeli, revealed a crest formed by appendages up to 15 centimeters long. Inside these appendages, researchers found melanosomes, responsible for color in feathers and skin, more similar to those in modern feathers. The way these appendages grew, expanding outward in concentric rings, resembles the development of feathers.
A more sophisticated animal than previously thought
The Mirasaura grauvogeli is not directly related to feathered dinosaurs or other groups showing complex appendages, suggesting this ability may have been more widespread among early reptiles than previously believed. The dorsal appendages of Mirasaura likely served a visual function to deter predators or warn competitors, supported by the animal’s advanced visual communication due to large frontal eye sockets in its skull.
Feathers, scales, or something in between?
While the structures of Mirasaura cannot be classified as true feathers, the discovery challenges the traditional view of skin evolution. Scientists believe that similarities in molecular mechanisms among feathers, scales, and hair stem from a common ancestor, an early amniote with the genetic tools for forming complex skin structures. Mirasaura grauvogeli becomes a key piece in the evolutionary puzzle, showing that reptiles were exploring diverse and sophisticated body coverings long before birds existed.
