Eobalaenoptera harrisoni is an extinct species of baleen whale. The species was first described in June 2004 by researchers at the Virginia Museum of Natural History. The researchers identified the species from a partial skeleton found in 1990 in Caroline County, Virginia, the site of a prehistoric ocean, in middle Miocene Calvert Formation rocks. The 11 m (35 ft) skeleton proved to have similar morphological characteristics to a clade of whales consisting of two modern taxonomic families - Balaenopteridae (the rorquals), and Eschrichtiidae (a family with one surviving species, the Gray Whale).