New fossil whales from Angola

Graf, J., Jacobs L. L., Polcyn M. J., Mateus O., & Schulp A. S. (2011).  New fossil whales from Angola. 71st Annual Meeting of the Society of Vertebrate Paleontology. 119., Jan: Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology


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Ongoing field work in Angola, under auspices of Projecto PaleoAngola, has yielded fossil cetaceans from deposits of Miocene age, providing new insights into the early diversification of cetaceans along the western African coast.
Here two new taxa of mysticete whales are described. PA 165 comprises a partial articulated skull, an unfused cervical vertebra, and a partial thoracic vertebra. The skull includes the nasals, proximal premaxillae and maxillae, the supraoccipital shield, left squamosal, exoccipital, periotic, and frontal. Portions of both dentaries are present. PA 166 comprises a partial articulated skull including the region posterior to and including the nasals. The proximal portions of the maxillae and premaxillae are present. Both specimens were recovered from what appears to be the Luanda Formation, a calcareous sandstone of late Miocene age. Phylogenetic analysis indicates these fossils represent two new taxa nested with Caperea marginata, the pygmy right whale, in the Neobalaenidae, a family currently restricted to one species inhabiting cold temperature Southern Hemisphere waters. Five characters unite the new Angolan taxa with Caperea, including the line joining the anterior points of the orbital processes of the frontals positioned anterior to the posterior extremity of the nasals, the posterior edge of the ascending process of the maxilla situated anterior to the orbit, the posterior edge of the nasal positioned just anterior to the anterior edge of the supraorbital process of the frontal, and the anterior point of the supraoccipital being in a transverse line with the anterior edge of the supraorbital process of the frontal. Three characters distinguish the Angolan taxa from Caperea, including the base of the rostrum being narrow, the zygomatic process of the maxilla underlying the supraorbital process of the frontal, and the lateral edges of the maxilla being parallel. Neobalaenidae is a sister group to Eschrichtiidae and alaenopteridae. These new taxa are the only known fossil representatives of the family, they triple its known diversity, and they extend its range into the Miocene phase of the Benguela Large Marine Ecosystem.