Paleontology in Oregon

Aetiocetus is a genus of extinct basal mysticete, or baleen whale that lived , in the Oligocene in the North Pacific ocean, around Japan, Mexico, and Oregon. It was first described by Douglas Emlong in 1966 and currently contains known four species, A. cotylalveus, A. polydentatus, A. tomitai, and A. weltoni. These whales are remarkable for their retention of teeth and presence of nutrient foramina, indicating that they possessed baleen. Thus, Aetiocetus represents the transition from teeth to baleen in Oligocene mysticetes. Baleen is a highly derived character, or synapomorphy, of mysticetes,

national monument in the United States

Simocetus (from simus, "pug-nosed", and cetus, "whale") is an extinct genus of toothed whale that lived during the Oligocene period, approximately , making it the oldest named toothed whale, although older unnamed toothed whales exist.

thumb|200 px|Spitidiscus seunesi (Wilfrid Kilian|Kilian) [[Barremian, Brestak, Cr1 426X1 (Coll. St. Breskovski) at the Sofia University Museum of Paleontology and Historical Geology]] Spitidiscus is a genus of ammonites placed in the family Holcodiscidae.