Scientists Discover Prehistoric Era: Beyond Giant Dinosaurs, There Were Other Mysterious Predators
During the late Age of Dinosaurs in North America, Tyrannosaurus rex stood out as the supreme ruler, one of the largest terrestrial predators in Earth’s history. However, scientists have found that in the prehistoric forests, alongside the dinosaurs, there were also ancient predatory birds, mysterious hunters that existed and evolved in their own unique ways.
Three fossil specimens (from left to right): Avisaurus darwini, Avisaurus sp., and Magnusavis ekalakaensis – (Photo: Alex Clark/physorg).
Recently, researchers discovered two new bird species from the Cretaceous period in Montana, dating back about 67 million years. These species not only have distinctive shapes but also share anatomical features similar to modern birds of prey such as hawks, owls, and eagles.
With their perfectly structured legs designed for capturing and carrying prey, they promise to provide scientists with fresh perspectives on life during that era.
The fossils of these two bird species were found in the same Hell Creek formation – a site that has previously revealed fossils of many famous dinosaurs such as T. rex and Triceratops.
Interestingly, both species are known only from a part of a leg bone called the tarsometatarsus – the bone connecting the ankle to the toes. The larger species, named Avisaurus darwini, could reach a size comparable to a large hawk, with a wingspan of about 1.3 meters, while the smaller species of the genus Avisaurus remains unnamed.
Reconstruction of an avisaurid bird – (Photo: Alex Clark/physorg).
According to Alex Clark, a PhD candidate at the University of Chicago, the similarities in the tarsometatarsus bone with modern birds of prey “suggest that they may have behaved similarly and lived in an ecosystem akin to what we see today.”
“They might have hunted small mammals, lizards, and even other birds, just like how hawks hunt today,” he noted.
Emerging around 150 million years ago, the first birds evolved from small feathered dinosaurs. These two new species belong to the enantiornithines group, one of the four major bird groups living during the Age of Dinosaurs, which became extinct after the meteor impact 66 million years ago, leading to the demise of many dinosaur species.
Although they are not ancestors of any living bird species, these predatory birds developed similar anatomical characteristics.
Previously, ancient predatory birds were thought to have appeared millions of years after the Quaternary period, when dinosaurs had already declined and mammals began to rise. The incomplete fossils of Avisaurus still leave many questions about their shape and characteristics.
One notable feature on the tarsometatarsus is the position of powerful muscles, similar to those in hawks and owls, indicating that this animal had strong leg muscles and feet capable of grasping large prey. Furthermore, the grooves on the tarsometatarsus, called trochlea, demonstrate the strength of the toes, an important characteristic that helped them control prey during flight.
The Mysterious Bird Species to Science In addition to the two aforementioned species, researchers also discovered a third new bird species – Magnusavis ekalakaensis. However, this bird remains a mystery to science. The findings not only enrich our understanding of the ecosystem during the late Age of Dinosaurs but also help fill the gaps in knowledge about the evolution of birds during this crucial period of life on Earth. |
