Birds, a remarkably diverse group with approximately 10,000 living species, still hold their early evolutionary history in mystery, according to paleontologists Miengah Abrahams and Emese Bordy from the University of Cape Town.
The Unveiling of Avian Origins
Modern birds trace their origin unequivocally to Maniraptora, a group of theropod dinosaurs, yet the timing of their origin remains contested. The oldest body fossil record of early birds includes Aurornis, Anchiornis, Archaeopteryx, and Xiaotingia from the Middle to Late Jurassic (150-160 million years ago). Dinosaurian footprints with bird-like morphologies date back to the Late Triassic.
Challenges in Osteological Records
However, the early osteological record is fragmented, leaving the exact origin of early birds in the Early or pre-Jurassic unconfirmed. Protoavis, posited as bird-like in the Late Triassic, is not widely accepted as a basal bird.
Reassessment of Fossilized Footprints
In a new study, researchers reevaluated fossilized footprints from southern Africa, challenging previous assignments to Trisauropodiscus, an ichnogenus. They identified two distinct Trisauropodiscus morphotypes—one resembling bird footprints and the other similar to non-avian dinosaur tracks.
Antiquity of Footprints
These footprints, over 210 million years old, predate the earliest known body fossils of true birds by about 60 million years. The findings suggest the origin of bird-like feet in the Late Triassic epoch, opening avenues for speculation about early dinosaurs or members of a parallel evolutionary track.
