Eobalaentopera 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 called the middle Miocene Calvert Formation of Virginia. 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).

The age of skeleton was estimated to be 14 million years, making the species the oldest known member of the clade by three to five million years. It also considerably narrowed the gap between the earliest known fossil record and estimated time of divergence of this clade from other baleen whales. Molecular studies have put this divergence time at around 25 million years.

The genus name Eobalaenoptera reflects the similarities between this skeleton and species in the genus Balaenoptera such as the Minke Whale; eo- is a prefix meaning ancient. The species is named after Carter Harrison, a volunteer worker at the museum.

References

• Alton. C. Dooley, Nicholas C. Fraser and Zhe-Xi Luo (2004). The Earliest Known Member of the Rorqual-Gray Whale Clade. Journal of Vertebrate Palaeontology 24 (2): 453-463.