''Morenocetus'' is an extinct genus of primitive balaenid 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 (), in older literature also referred to as Patagonian Marine Formation (, ''Patagoniense''), is a list of fossiliferous stratigraphic units in Argentina, fossiliferous geologic Formation (geology), formation of the Peninsula ...

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

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'' 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 Robert Ewan Fordyce (14 July 1953 – 10 November 2023) was a New Zealand palaeontologist. He specialised in the evolution of whales, dolphins, and early penguins. Life and career Fordyce joined the Department of Geology at the University of ...

.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