Fossil footprints dating back 215 million years challenge the timeline of bird evolution
Footprints preserved in stone in Lesotho, Africa, have revealed the existence of animals with birdlike feet that walked the Earth around 215 million years ago. This discovery pushes back the timeline of bird evolution by millions of years, as the earliest known bird ancestors date back 150 to 160 million years. The findings, based on research conducted by Miengah Abrahams and Emese Bordy from the University of Cape Town, South Africa, shed new light on the evolutionary history of birds and their ancient relatives.
Trisauropodiscus: The Enigmatic Footprints
Abrahams and Bordy studied an 80-meter-long stretch of footprints at a site called Maphutseng, as well as casts and sketches from four other sites in Lesotho. Their focus was on a specific type of footprint called Trisauropodiscus, which is characterized by its distinctive three-toed shape. The exact identity of the animals that made these footprints remains a mystery.
Birdlike Feet and Anomoepus: Two Distinct Groups
The researchers discovered that the Trisauropodiscus footprints could be divided into two main groups based on their shape. One group exhibited birdlike characteristics, with a wide splay in the outer digits and slender toes. These footprints closely resemble those of modern and fossilized bird tracks. The second group had more rounded, robust, and elongated toes, resembling another type of footprint known as Anomoepus. Anomoepus footprints are associated with dinosaurs that possess birdlike hips.
Early Evolution of Birdlike Feet
The presence of two distinct groups of Trisauropodiscus footprints suggests that birdlike feet evolved much earlier than previously believed, and potentially independently in different animal groups. This challenges the traditional timeline of bird evolution, which posits that bird ancestors emerged around 150 to 160 million years ago. The newfound footprints indicate that birdlike feet may have evolved as early as 215 million years ago.
Unraveling the Identity of the Footprint Makers
Despite the significant discovery, the exact identity of the animals responsible for the footprints remains uncertain. While they are confident that the footprints were not made by birds, Abrahams and Bordy are unable to determine which specific dinosaur species created them. The absence of comparable fossils in the local record adds to the mystery surrounding these enigmatic footprints.
The ancient footprints found in Lesotho provide compelling evidence that birdlike feet evolved much earlier in Earth’s history than previously known. The discovery challenges existing theories about the timeline of bird evolution and raises questions about the identity of the animals that left these footprints. Further research and exploration are necessary to unravel the mysteries of these ancient creatures and their place in the evolutionary history of birds. The findings highlight the ongoing nature of scientific discovery and the ever-evolving understanding of our planet’s rich biodiversity.