In southern Africa, fossil footprints have been discovered, revealing new insight into the early days of birds. These bird-like tracks suggest that the first birds might have appeared much earlier than we thought—around 210 million years ago—during the Triassic Period, which was the first chapter of the “Age of Dinosaurs.”
Today, birds are a common sight, with over ten thousand different species worldwide. However, the question is when birds came into existence.
We now know that birds are essentially a type of dinosaur that managed to survive the massive extinction caused by an asteroid hitting Earth about sixty-six million years ago. However, the exact timing of when birds first showed up remains a bit of a mystery.
The oldest bird, Archaeopteryx
Archaeopteryx, which means “old wing,” is believed to be the oldest bird, having lived around a hundred and fifty million years ago. Discovered in Germany in the late nineteenth century, its fossils were long considered the earliest evidence of avian existence.
However, in the past fifteen years, researchers have identified older potential bird ancestors such as the Anchiornis, Xiaotingia, and Aurornis, all dating back to around one hundred and sixty million years ago. A recent study published in PLOS ONE challenges the timeline further, proposing that the first birds might have appeared fifty to sixty million years earlier.
Focus of the research on fossil footprints
The research focused on fossil footprints known as Trisauropodiscus, which is a classification based on the impressions left by an organism rather than a reference to its actual body. These footprints have been found in various sites across southern Africa, particularly in Lesotho.
By studying Trisauropodiscus traces at four different locations, scientists identified two distinct shapes. One resembled tracks left by non-avian dinosaurs, while the other closely matched the size and proportions of bird footprints.
This discovery adds a new layer to the ongoing debate among paleontologists about the identity and diversity of Trisauropodiscus species.
Who made the Trisauropodiscus tracks?
The identity of the creature responsible for the Trisauropodiscus tracks remains a puzzling mystery, especially considering that the earliest known birds are believed to have emerged at least fifty million years later.
According to Dr. Miengah Abrahams and Professor Emese Bordy from the University of Cape Town, the only potential bird-like candidate from the Late Triassic Period is Protoavis. However, this assessment is met with skepticism due to ambiguous fossil material and a lack of widespread acceptance as a basal, or archaic, bird.
Animals with bird-like feet roamed planet 200 million years ago, say scientists#Analysis of ancient footprints, which experts were calling Trisauropodiscus, suggest these creatures were likely to have been three-toed. It is unclear who made the track marks, but experts speculate… pic.twitter.com/aXIyaRadzr
— CHAUDHRY IMRAN (@chimran55) November 30, 2023
The authors believe the footprints might have been created by an early dinosaur, possibly belonging to a lineage closely related to birds. Alternatively, it is plausible that another reptile species evolved feet resembling those of modern birds.
Location of the tracks
The Trisauropodiscus tracks have been identified in various southern African sites dating back approximately two hundred and fifteen million years. While the shape of these tracks aligns with both modern and more recent fossilized bird tracks, the authors propose that a dinosaur with bird-like feet could have produced them.
Until a fossil of an animal from the right time, in the right place, and with the right proportions is discovered, the enigma of the Trisauropodiscus tracks and the creature behind them remains unsolved.