Vestibular evidence for the evolution of aquatic behaviour in early cetaceans

F. Spoor (), S. Bajpai, S. T. Hussain, K. Kumar and J. G. M. Thewissen
Additional contact information
F. Spoor: University College London, Rockefeller Building
S. Bajpai: Indian Institute of Technology
S. T. Hussain: Howard University
K. Kumar: Wadia Institute of Himalayan Geology
J. G. M. Thewissen: Northeastern Ohio Universities College of Medicine

Nature, 2002, vol. 417, issue 6885, 163-166

Abstract: Abstract Early cetaceans evolved from terrestrial quadrupeds to obligate swimmers, a change that is traditionally studied by functional analysis of the postcranial skeleton 1 . Here we assess the evolution of cetacean locomotor behaviour from an independent perspective by looking at the semicircular canal system, one of the main sense organs involved in neural control of locomotion2. Extant cetaceans are found to be unique in that their canal arc size, corrected for body mass, is approximately three times smaller than in other mammals. This reduces the sensitivity of the canal system, most plausibly to match the fast body rotations that characterize cetacean behaviour. Eocene fossils show that the new sensory regime, incompatible with terrestrial competence, developed quickly and early in cetacean evolution, as soon as the taxa are associated with marine environments. Dedicated agile swimming of cetaceans thus appeared to have originated as a rapid and fundamental shift in locomotion rather than as the gradual transition suggested by postcranial evidence. We hypothesize that the unparalleled modification of the semicircular canal system represented a key ‘point of no return’ event in early cetacean evolution, leading to full independence from life on land.

Date: 2002
References: Add references at CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.nature.com/articles/417163a Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:417:y:2002:i:6885:d:10.1038_417163a

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/417163a

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().