The most ancient of these footprints, at over 210 million years old, are 60 million years older than the earliest recognized body fossils of real birds.
These footprints, which vary from any recognized fossil animals of that period, suggest that either other reptiles or early dinosaurs may have evolved bird-like feet, predating the earliest bird fossils by 60 million years. In this study, the researchers reassessed the fossil record of these footprints, taking a look at physical fossil traces together with published products recording Trisauropodiscus at four sites in Lesotho dating to the Late Triassic and Early Jurassic Periods. They recognized 2 distinct morphologies among Trisauropodiscus footprints, the very first of which is similar to certain non-bird dinosaur tracks, and the second of which is very similar in size and proportions to the footprints of birds.
Fossilized Trisauropodiscus tracks and modern bird tracks. Credit: Abrahams et al., CC-BY 4.0
Ramifications and Origin of Bird-Like Feet
These tracks arent a direct match for any fossil animals understood from this region and period. The most ancient of these footprints, at over 210 million years of ages, are 60 million years older than the earliest known body fossils of real birds. Its possible that these tracks were produced by early dinosaurs, and possibly even early members of a near-bird family tree, but the authors keep in mind that there might also have actually been other reptiles, cousins of dinosaurs, that convergently evolved bird-like feet. Whoever the trackmakers are, these footprints develop the origin of bird-like feet at least as early as the Late Triassic Period.
The authors include: “Trisauropodiscus tracks are known from many southern African sites going back to approximately 215 million years back. The shape of the tracks follows modern and more recent fossil bird tracks, but it is likely a dinosaur with a bird-like foot produced Trisauropodiscus.”
Reference: “The earliest fossil bird-like footprints from the upper Triassic of southern Africa” by Miengah Abrahams and Emese M. Bordy, 29 November 2023, PLOS ONE.DOI: 10.1371/ journal.pone.0293021.
This discovery comes from an analysis of Trisauropodiscus footprints discovered in southern Africa, dating back to the Late Triassic and Early Jurassic Periods. These footprints, which vary from any recognized fossil animals of that period, suggest that either early dinosaurs or other reptiles might have developed bird-like feet, preceding the earliest bird fossils by 60 million years.
These tracks pre-date the earliest bird bone by around 60 million years.
Ancient animals were walking around on bird-like feet over 210 million years ago, according to a research study released on November 29, 2023, in the open-access journal PLOS ONE by Miengah Abrahams and Emese M. Bordy of the University of Cape Town, South Africa.
Insights Into Trisauropodiscus Footprints
Numerous fossil sites in southern Africa preserve unique three-toed footprints that have been called Trisauropodiscus. For several years, scientists have debated what animals may have left these tracks, along with exactly the number of various types (technically called ichnospecies) of Trisauropodiscus there are.
In this study, the researchers reassessed the fossil record of these footprints, examining physical fossil traces together with published products recording Trisauropodiscus at four sites in Lesotho dating to the Late Triassic and Early Jurassic Periods. The authors also offered an in-depth field-based description of footprints from an 80-meter-long (260-foot-long) tracksite in Maphutseng. They identified 2 distinct morphologies among Trisauropodiscus footprints, the very first of which is similar to specific non-bird dinosaur tracks, and the second of which is extremely comparable in size and percentages to the footprints of birds.