A new Miocene baleen whale from the Peruvian desert

The Pisco-Ica and Sacaco basins of southern Peru are renowned for their abundance of exceptionally preserved fossil cetaceans, several of which retain traces of soft tissue and occasionally even stomach contents. Previous work has mostly focused on odontocetes, with baleen whales currently being res...

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Bibliographic Details
Published in:Royal Society Open Science
Main Authors: Marx, Felix G., Kohno, Naoki
Format: Article in Journal/Newspaper
Language:English
Published: 2016
Subjects:
Online Access:https://research.monash.edu/en/publications/f96486bb-7744-46f5-9e8b-adfd7a3ccb64
https://doi.org/10.1098/rsos.160542
https://researchmgt.monash.edu/ws/files/281980137/281980056_oa.pdf
http://www.scopus.com/inward/record.url?scp=84990941271&partnerID=8YFLogxK
Description
Summary:The Pisco-Ica and Sacaco basins of southern Peru are renowned for their abundance of exceptionally preserved fossil cetaceans, several of which retain traces of soft tissue and occasionally even stomach contents. Previous work has mostly focused on odontocetes, with baleen whales currently being restricted to just three described taxa. Here, we report a new Late Miocene rorqual (family Balaenopteridae), Incakujira anillodefuego gen. et sp. nov., based on two exceptionally preserved specimens from the Pisco Formation exposed at Aguada de Lomas, Sacaco Basin, southern Peru. Incakujira overall closely resembles modern balaenopterids, but stands out for its unusually gracile ascending process of the maxilla, as well as a markedly twisted postglenoid process of the squamosal. The latter likely impeded lateral (omega) rotation of the mandible, in stark contrast with the highly flexible craniomandibular joint of extant lungefeeding rorquals. Overall, Incakujira expands the still meagre Miocene record of balaenopterids and reveals a previously underappreciated degree of complexity in the evolution of their iconic lunge-feeding strategy.