Bony-Tongue Fishes (Teleostei: Osteoglossomorpha) from the Eocene Nanjemoy Formation, Virginia

Abstract

Bony-tongue fishes, Osteoglossomorpha, are distributed in North and South America, Africa, Asia, and Australia and are found on all continents except Antarctica in the fossil record. The group includes fishes such as the mooneyes (Hiodontidae), freshwater knifefishes (Notopteridae), elephantfishes (Mormyridae), and the arowanas and pirarucu (Osteoglossidae). Remains identified as belonging to the family Osteoglossidae are known from the Nanjemoy Formation of Maryland and northern Virginia and comprise isolated teeth and fragmentary jaw bones assigned to the now extinct ???Brychaetus muelleri. The second author discovered a partial toothed parasphenoid among other isolated and fragmentary vertebrate microfossils from the Fisher???Sullivan Site of the Nanjemoy Formation in northern Virginia. This element resembles the base of the parasphenoid of the extant osteoglossid taxa Osteoglossum and Scleropages. Although this fossil is fragmentary and not sufficient to differentially diagnose taxonomically, it provides further evidence of the substantial diversity of Osteoglossidae during the Eocene.