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."
New Bovid fossils from the Late Miocene Hasnot (Siwaliks, Pakistan)
Authors:
Batool et al
Abstract:
The Siwalik Late Miocene bovids from the Hasnot deposits of Northern Pakistan are described here. The bovids are represented predominantly by boselaphines. The Hasnot outcrops range 7–5 Ma and correspond to the fauna of the Late Miocene–Early Pliocene of Eurasia and Africa. The associated fauna of the Hasnot is suggestive a vast open land environment depicting sporadic dry and flood seasons, forcing a mosaic of ecotonal habitats with countless number of niches.
