What is "morganucodonta"

Morganucodonta (" Glamorgan teeth") is an extinct order of primitive mammaliaformes similar to crown-group mammals. Their remains have been found in southern Africa, Western Europe, Arizona and China. The morganucodonts were most likely insectivorous and nocturnal, seeking prey while avoiding predators that were usually active by day. Such a trait may have been inherited by their descendants to avoid the predatory dinosaurs, though some of the latter were nocturnal as well.