Ascaphus

Ascaphus is a genus of frogs which are basal to all other frogs. They are highly adapted for life in swift, small streams, the males have an intromittent mating organ, and the tadpoles a suctatorial mouth (see below). Ascaphus are found only in the Pacific Northwest and as far east as the western slopes of the Rocky Mountains. See the links below for full species accounts and professional photos.

http://www.californiaherps.com/frogs/pages/a.truei.html

http://amphibiaweb.org/cgi/amphib_query?where-genus=Ascaphus&where-species=truei

http://www.iucnredlist.org/details/54414/0

Tadpole of Ascaphus truei