''Morenocetus'' is an extinct genus of primitive

balaenid Balaenidae () is a Family (biology), family of whales of the parvorder Mysticeti that contains two living genera: the right whales (genus ''Eubalaena''), and in a separate genus, the closely related bowhead whale (genus ''Balaena''). Evolutionar ...

from the Early Miocene (

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

and

Colhuehuapian The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...

in the SALMA classification)

Gaiman Formation The Gaiman Formation ( es, Formación Gaiman), in older literature also referred to as Patagonian Marine Formation ( es, Formación Patagonia Marino, ''Patagoniense''), is a fossiliferous geologic formation of the Peninsula Valdés Basin in the e ...

of Patagonia,

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Description

''Morenocetus'' is distinguished from more derived balaenids in the narrow exposure of the squamosal lateral to the exoccipital, a short supraorbital process of the frontal, straight lateral edges of the supraoccipital, and a postorbital process of the frontal oriented posteriorly. It can be distinguished from the only other Miocene balaenid, ''

Peripolocetus ''Peripolocetus'' is a genus of balaenid baleen whale from the middle Miocene of Kern County, California.M. D. Uhen, R. E. Fordyce, and L. G. Barnes. 2008. Mysticeti. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary Mam ...

'' in having a dorsoventrally expanded zygomatic process of the squamosal. The body length of ''Morenocetus'' is estimated at , and the rostrum is moderately arched dorsoventrally in contrast to crown Balaenidae.

Classification

''Morenocetus'' is the oldest named extinct balaenid so far, although a chaeomysticete specimen from late Oligocene marine deposits in New Zealand was reported as a stem-balaenid in an SVP 2002 abstract by

Ewan Fordyce Ewan is an anglicisation of the Scottish Gaelic name Eòghann. It is possibly a derivative of the Pictish name, ''Vuen'' (or 'Wen'), "The Warrior" or "born of the mountain". It is most common as a male given name in Scotland and Canada. It is a ...

.Fordyce, R.E., 2002. Oligocene origin of skim–feeding right whales: a small archaic balaenid from New Zealand. ''Journal of Vertebrate Paleontology'' 22:54A

Description

Classification

References

Further reading