(cohort Unguiculata, order Insectivora)
A suborder that comprises a large number of extinct forms the earliest of which lived during the late Cretaceous. At that time the early eutherians appear to have diverged to form two distinct stocks, the Leptictidae and Deltatheridiidae, distinguished mainly by the structure of their teeth; both are included in the Proteutheria. There were many evolutionary side-branches which became extinct, but among successful proteutherians some may be ancestral to rodents and others may be ancestral to primates. Proteutheria are often excluded from the Insectivora, or even divided into two or more separate orders.
Subjects: Zoology and Animal Sciences.