High Quality Content by WIKIPEDIA articles! Enantiornithes is an extinct group of primitive birds. They were the most abundant and diverse avialans of the Mesozoic. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over 50 species of Enantiornithines have been named, but some names represent only single bones, so it is likely that not all are valid. Enantiornithine birds went extinct at the K-Pg boundary, along with hesperornithine birds and all other non-avian dinosaurs, and many other mostly reptilian life forms. Enantiornithines are thought to have left no living descendants.