Another ancient bird skull is another bit of avian history

FOSSIL BY FOSSIL, the story of the birds becomes clearer. It is now well established that modern birds, the Neornithes, are actually a relict group of dinosaurs which survived a cosmic collision, 66m years ago, between Earth and an asteroid or comet. This impact wiped out the rest of the Dinosauria, along with a lot of other creatures. A paper published last week about a tiny dinosaur belonging to a related group, the Enantiornithes, which was found preserved in amber in what is now Myanmar, showed just how diverse flying dinosaurs had become more than 30m years before this collision. This week sees the release, in a paper in , of details of another fossil, which those studying it believe is close to the point of origin of the Neornithes themselves.The fossil in question is called . As its name suggests, the rock containing it was dug from deposits found near Maastricht—though actually over the border from that Dutch city, in Belgium. These deposits, which are between 66.8m and 66.7m years old, date from the end of the Cretaceous period. Indeed, and not coincidentally, the name of the last stage of this period is the Maastrichtian, for these are strata that originally defined it.