What is "bisonalveus"

Bisonalveus is an extinct genus of shrew-like mammals that were presumably ground-dwelling and fed on plants and insects. Bisonalveus fossils have been discovered in the upper Great Plains region of North America, including sites in modern-day Wyoming, North Dakota, Montana, and Alberta. The fossils have been dated to 60 million years ago, during the Tiffanian North American Stage of the Palaeocene epoch. Bisonalveus is the last known genus of the Pentacodontinae sub-family to have arisen, replacing the Coriphagus genus in the early Tiffanian. Bisonalveus itself appears to have gone extinct by the middle Tiffanian.

Bisonalveus is represented by two known species: B. browni (Gazin, 1956) and B. holtzmani (Gingerich, 1983).