This is the
most primitive order of placental mammals. The modern insectivores'
skull and teeth, size, and habits are similar to those of the
ancient, small nocturnal insectivores that lived along with
dinosaurs. Insectivores are generally small. They range over
most of the world's land surface except for the Australian and
southern neotropical regions, Antarctic and most oceanic islands.
Sixty-four species of mouse-sized African and Eurasian mammals make up nearly half of the more than 325 species of true shrews (family Soricidae). No other genus of mammals contains as many species. Seven were named during the last decade of the 20th century, and undoubtedly new species await discovery.
Many have mobile snouts that are covered with long, sensitive whiskers and overhang the lower lip. Their large incisor teeth are used like forceps to grab prey; the upper pair is hooked, and the lower pair extends forward.