Science Daily introduces us to a new… or, well, very, very old beast – a prehistoric gnu that trumpeted like a duck-billed dinosaur:
By poring over the fossilized skulls of ancient wildebeest-like animals (Rusingoryx atopocranion) unearthed on Kenya’s Rusinga Island, researchers have discovered that the little-known hoofed mammals had a very unusual, trumpet-like nasal passage similar only to the nasal crests of lambeosaurine hadrosaur dinosaurs. The findings reported in the Cell Press journal Current Biology on February 4 offer “a spectacular example” of convergent evolution between two very distantly related taxa and across tens of millions of years, the researchers say.
“The nasal dome is a completely new structure for mammals– it doesn’t look like anything you could see in an animal that’s alive today,” says Haley O’Brien of Ohio University, Athens. “The closest example would be hadrosaur dinosaurs with half-circle shaped crests that enclose the nasal passages themselves.”
This evolutionary convergence may be explained by similarities in the way Rusingoryx and hadrosaurs lived. In fact, hadrosaurs are sometimes referred to as the “cows of the Cretaceous.”
The researchers also uncovered stone tools and butchered bone, raising the possibility that early modern humans had something to do with the peculiar concentration of Rusingoryx skeletons. In 2011, study co-author Kirsten Jenkins of the University of Minnesota took charge of excavations, hoping to find more complete fossils and to establish why so many skeletons had ended up in that spot. Along the way, she found several intact skulls.
“I was astonished to see that [the skulls] looked unlike any antelope that I had ever seen–the only thing more surprising would have been fossil zebras with horns growing from their heads!” Faith says. “The anatomy was clearly remarkable.”