The bird-like tridactyl (three-toed) footprints found at the site of Maphutseng in Lesotho predate the oldest known bird body fossils by approximately 60 million years, and were left by an unknown animal, likely an early dinosaur.
“Birds are one of the most diverse groups of animals on Earth with around 10,000 living species, yet their early evolutionary history is still shrouded in mystery,” said University of Cape Town paleontologists Miengah Abrahams and Emese Bordy.
“The dinosaurian origin of modern birds unequivocally points to Maniraptora, a group of theropod dinosaurs, but the timing of the origin of birds is contested.”
“The oldest body fossil record of early birds comprises Middle to Late Jurassic (150-160 million years ago) Aurornis, Anchiornis, Archaeopteryx and Xiaotingia, while dinosaurian footprints with bird-like morphologies are known since the Late Triassic.”
“The early birds known from body fossils likely originated in the Early or pre-Jurassic, although, to-date, this is unconfirmed by the early osteological record that is exceedingly fragmentary.”
“The only Late Triassic body fossil specimen posited to be bird-like is Protoavis, but this assessment is based on ambiguous material and is not widely accepted to be a basal bird.”
“In this context, all ancient bird-like paleontological discoveries are vital for unravelling both the origin of birds and the evolution of dinosaurs.”
In the new study, the researchers reassessed the fossilized footprints — previously assigned to the ichnogenus Trisauropodiscus — from four locations in Lesotho, southern Africa.
They also provided a detailed field-based description of footprints from an 80-m-long tracksite at the site of Maphutseng.
“Multiple tridactyl tracks with a ‘proto-avian’ morphology from the Late Triassic and Early Jurassic of southern Africa were assigned to Trisauropodiscus in the mid-1900s,” they explained.
“Based on the interpretive sketches and brief…
Read the full article here