Body coverings such as hair and feathers have long played a central role in the evolution of species, enabling warm-bloodedness by insulating the body and serving purposes in courtship, display, deterrence of enemies, and flight. Traditionally, these complex structures have been associated with mammals and birds, with reptiles characterized by simpler, flat scales. However, a groundbreaking discovery by an international team of palaeontologists led by Dr. Stephan Spiekman and Prof. Dr. Rainer Schoch from the State Museum of Natural History Stuttgart, Germany, is challenging these long-held beliefs.
The team has unearthed a previously unknown tree-dwelling reptile from the early Middle Triassic period, named Mirasaura grauvogeli, or ‘Grauvogel’s Wonder Reptile’. This 247-million-year-old fossil reveals a dorsal crest with complex appendages reminiscent of feathers, suggesting that such intricate skin structures may predate modern reptiles. Published in the journal Nature, this discovery is prompting a reevaluation of reptile evolution.
Unique Skin Structures in Early Reptiles
The crest of Mirasaura consists of individual, densely overlapping appendages with a feather-like contour and a narrow central ridge. Unlike true feathers, which have delicate branched structures called barbs, Mirasaura‘s appendages lack such branching. This led researchers to conclude that these complex skin structures evolved independently of those found in birds.
‘The fact that we have discovered such complex skin appendages in such an ancient group of reptiles sheds new light on their evolution. Mirasaura is even older than the dinosaurs and not closely related to them,’ said Dr. Stephan Spiekman, lead author of the study.
Dinosaurs and the Origin of Feathers
This discovery marks a significant shift in palaeontological research, which has evolved over the past 30 years since the late 1990s when feathered dinosaurs were first discovered in China. Previously, it was believed that reptiles, including dinosaurs, were covered with scales and that only true birds had feathers. This perception changed with evidence showing that many dinosaurs were more bird-like than previously thought.
‘Mirasaura grauvogeli shows us how surprising evolution can be and what potential it holds. It repeatedly produces similar structures that are completely independent of each other,’ commented Prof. Dr. Rainer Schoch.
Bizarre Tree-Climbers with Bird-Like Features
Advanced technologies, including synchrotron imaging at the European Synchrotron (ESRF), have been employed to study Mirasaura, revealing a bird-like skull with a narrow, mostly toothless snout and large, forward-facing eye sockets. Belonging to the drepanosauromorphs, Mirasaura is part of a group known for their bizarre adaptations, such as grasping forelimbs and prehensile tails.
‘Drepanosaurs have many ecological adaptations and have only been known to science for a few decades. The dorsal crest with a novel skin structure in Mirasaura adds to the range of remarkable adaptations that make this group of reptiles so unique,’ said Prof. Dr. Hans Sues from the National Museum of Natural History, Washington DC.
Grauvogel’s ‘Wonder Reptile’
The story of Mirasaura begins with fossil collector Louis Grauvogel, who started excavating in Alsace, France, in the 1930s. His collection, which included the remains of Mirasaura, was transferred to the State Museum of Natural History Stuttgart in 2019. The fossils are now part of the museum’s palaeontological collection, and the site where Mirasaura was found is under further investigation.
The State Museum of Natural History Stuttgart, a leading research and communication institute, houses over 12 million objects and is dedicated to studying the evolution of life and biodiversity. The research on Mirasaura was funded by the DFG – Deutsche Forschungsgemeinschaft and the European Research Council.
As scientists continue to explore the implications of this discovery, Mirasaura grauvogeli stands as a testament to the complexity and unpredictability of evolution, offering new insights into the history of reptiles and their development over millions of years.
