- The shared historical past of birds and dinosaurs is well-established, however precisely how true birds advanced through the Mesozoic is a little bit of a thriller.
- Adding to this conundrum are fossilized footprints of bird-like tracks which can be 210 million years old—a very good 60 million years earlier than the arrival of the genus Archaeopteryx, one of many oldest true birds ever found.
- While scientists can’t verify what produced these tracks, it positively establishes that hen toes advanced tens of millions of years sooner than we beforehand thought.
The age of the dinosaurs by no means actually ended—it solely advanced. Birds (and their extra reptilian cousins, the Crocodilia) are the modern-day legacy of dinosaur’s 165-million-year-long stint on Earth. While our avian associates’ Mesozoic origin story isn’t up for debate, the timing of when birds first arrived on Earth isn’t as clear reduce.
Exhibit A on this prehistoric thriller is a collection of bird-like footprints on the Maphutseng paleontological website in Lesotho. Drawing information from 4 websites—together with an in depth 262-foot-long set of fossil prints—scientists on the University of Cape Town (UCT) identified two types of footprints belonging to the Trisauropodiscus, a sort of three-toed dinosaur from the Late Triassic/Early Jurassic whose fossils are frequent throughout Africa.
One set of tracks resembles footprints discovered at different websites. But a second set is surprisingly just like hen tracks, which have been half the dimensions of the opposite tracks, wider than they have been taller, and contained slender toes. While these are all frequent attributes of hen tracks, there’s only one downside—true birds don’t arrive within the fossil document till some 60 million years later, within the Late Jurassic. UCT scientists revealed the outcomes of their research final week in the journal PLOS ONE.
“Fossil tracks of early birds and theropods, the co-existing dinosaurian ancestors of birds, co-occur in the rock record since the Early Cretaceous. However, the evolutionary transition from dinosaur to bird and the timing of the birds’ origin are still contested,” the paper reads. “That these tracks of southern Africa, dating to the Late Triassic, so strongly resemble Cenozoic and modern bird tracks substantiates the converging pedal morphology of Late Mesozoic archosaurs and firmly shows that the origin of bird-like foot morphology is at least ~210 million years old.”
Although scientists now have these early, bird-like footprints, they’re not sure precisely who made them. The researchers say that they might belong to the earliest identified ancestor of the trendy birds, or to a dinosaur that belongs to the near-bird lineage. However, it’s additionally potential that it is a case of convergent evolution—one other, unrelated species might have independently advanced the identical sort of foot. What may be confirmed is that the evolution of bird-like toes is formally many tens of millions of years older than we initially thought.
It wasn’t till 1861 that the invention of Archaeopteryx—a Jurassica-era proto-bird—revealed the dino ancestory of the trendy hen. In the 160 years since, paleotonlogists have solely drawn extra connection between the category Aves and their reptilian forebears. T. rexes may now be displayed of their extra resplendent plumage, however mysteries like these tracks present in Lesotho show that there’s nonetheless much more to study early creatures.
Darren lives in Portland, has a cat, and writes/edits about sci-fi and the way our world works. You can discover his earlier stuff at Gizmodo and Paste in the event you look onerous sufficient.
