DESCRIPTION OF A 2ND SPECIES OF THE CATFISH DAGGER-HYPSIDORIS AND A REEVALUATION OF THE GENUS AND THE FAMILY DAGGER-HYPSIDORIDAE

A second species of the genus dagger Hypsidoris is described from the primitive catfish family dagger Hypsidoridae. The new species is from Eocene freshwater deposits of the Clarno Formation of central Oregon a nd is known by numerous well-preserved skeletons. Like the type specie s from the Green River Formation of Wyoming, the Oregon species has a well-developed toothed maxilla, a feature thought to be primitive amon g catfishes. Among the more than 35 nominal families containing over 2 ,200 species of catfishes, only Diplomystidae and dagger Hypsidoridae have well-developed toothed maxillae. The relationships of dagger Hyps idoridae to other catfishes are briefly reviewed. The associated ichth yofauna is also briefly discussed in context with other Eocene faunas of western North America.