Nilopegamys plumbeus Osgood 1928 , Field Mus . Nat. Hist., Zool. Ser., 12: 185 Order Rodentia - Family Muridae Wilson, Don E. Reeder, DeeAnn 47F6C Osgood 1928 Osgood 1928 Mammalia Muridae Nilopegamys Animalia Rodentia 1417 Chordata species plumbeus     Nilopegamys plumbeusOsgood 1928, Field Mus. Nat. Hist., Zool. Ser., 12: 185.   Type Locality: NW Ethiopia, Gojjam, Little Abbai, a small stream that is a tributary of the Blue Nile (11E7'20"N, 37E12'40"W); see Kerbis Peterhans and Patterson (1995)for additional information.   Vernacular Names: Ethiopian Amphibious Rat.   Distribution:Recorded only from the type locality.   Conservation: IUCN– Critically Endangered.   Discussion:Represented only by the type specimen, which is morphologically similar to  Colomys. Kerbis Peterhans and Patterson (1995)enumerated the traits they considered to distinguish the two genera and noted that  N. plumbeushas the largest cranial capacity and foramen magnum area of any African muroid sampled, close only to  Colomys,  Malacomys, and  Deomys. Amphibious rodents exhibit large brains relative to body size with an enlarged medulla oblongata, which is correlated with an expansive foramen magnum ( Voss, 1988). Kerbis Peterhans and Patterson (1995)contended that  N. plumbeushas more morphological adaptations reflecting an amphibious life style than any other African muroid, including  C. goslingi. That  plumbeusrepresents a monophyletic group separate from the species of  Colomys, however, is not universally accepted and the significance of the traits enumerated by Kerbis Pererhans and Patterson (1995) distinguishing  Nilopegamysand  Colomysis being tested by Hutterer and his colleagues within the context of a systematic revision of  Colomys( R. Hutterer, in litt., 1999). 4867324813 Ethiopia 1417