''"Balaenoptera" ryani'' is an extinct species of Balaenopteridae from the late Miocene of California. It was originally considered a species of ''

Balaenoptera ''Balaenoptera'' () is a genus of rorquals containing eight extant species. ''Balaenoptera'' comprises all but two of the extant species in its family (the humpback whale and gray whale); the genus is currently polyphyletic, with the two aforem ...

'', but is now recognized as more primitive than any extant or fossil balaenopterid and thus in need of a new generic name.T. A. Demere, A. Berta, and M. R. McGowen. 2005. The taxonomic and evolutionary history of modern balaenopteroid mysticetes. Journal of Mammalian Evolution 12(1/2):99-143

Taxonomy

The holotype of this species is CASG 1733, a partial skull from the Late

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

(

Tortonian The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian. The Torton ...

)

Monterey Formation The Monterey Formation is an extensive Miocene oil-rich geological sedimentary formation in California, with outcrops of the formation in parts of the California Coast Ranges, Peninsular Ranges, and on some of California's off-shore islands ...

of Saucito Rancho,

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. In their description of '' Parabalaenoptera'', Zeigler et al. (1997) assigned ''B. ryani'' to

Cetotheriidae Cetotheriidae is a family of baleen whales (parvorder Mysticeti). The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by recovered the living py ...

,Zeigler, C. V., Chan, G. L., and Barnes, L. G. (1997). A new late Miocene balaenopterid whale (Cetacea: Mysticeti), Parabalaenoptera baulinensis, (new genus and species) from the Santa Cruz Mudstone, Point Reyes Peninsula, California. Proc. Calif. Acad. Sci. 50: 115–138. but a recent overview of fossil balaenopterid taxa considers it a distinct genus of balaenopterid based on a unique combination of primitive and derived characters.

Description

Demere et al. (2005) note that ''Balaenoptera ryani'' can be diagnosed by a unique combination of characters found in both Balaenopteridae and non-balaenopterid thalassotheres: a supraorbital process of the frontal abruptly depressed below vertex, parietals overlapping posteromedial corner of the supraorbital process of frontal, sinuous and horizontally oriented squamosal cleft, lambdoidal crests broadly overhanging temporal fossa, and petrosal with triangular anterior process, sharply triangular supraoccipital shield, parietal narrowly exposed on vertex, and no overlap between the anterior wing of the parietal and ascending process of the maxilla.

References

Miocene cetaceans Fossil taxa described in 1924 Miocene mammals of North America {{paleo-whale-stub