A comparative analysis on cranial ontogeny of South American fur seals (Otariidae: Arctocephalus). (1st December 2014)

• Record Type: Journal Article
• Authors: Tarnawski, Bárbara A.; Flores, David; Cassini, Guillermo; Cappozzo, Luis H.
• Is Part Of: Zoological journal of the Linnean Society. Volume 173:Number 1(2015:Jan.)
• Page Start: 249
• Page End: 269
• Publication Date: 2014-12-01
• Subjects: Zoology -- Periodicals; 590
• DOI: 10.1111/zoj.12197
• Languages: English
• ISSNs: 0024-4082

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>We analysed the cranial ontogeny of male <italic>Arctocephalus australis</italic> (Zimmermann, 1783) (<italic>N</italic> = 116), <italic>Arctocephalus gazella</italic> (Peters, 1875) (<italic>N</italic> = 69), and <italic>Arctocephalus tropicalis</italic> (Gray, 1872) (<italic>N</italic> = 51) to study skull growth and its allometric patterns in the genus. We used 15 metric variables with bivariate and multivariate approaches to detect interspecific similarities and differences between growth trends, which we discussed in the context of phylogeny and life history. We found common trajectories in 20% of variables, detecting that the differences between adults were associated with size. We detected higher growth rates in <italic>A. gazella</italic> than in <italic>A. australis</italic> and <italic>A. tropicalis</italic>, which were associated with shape differences. Amongst the three species, <italic>A. tropicalis</italic> was morphologically intermediate, showing additional common trends with <italic>A. gazella</italic> and <italic>A. australis</italic>, and an intermediate position in the multivariate morphospace. Allometric patterns were also compared with growth trends described for <italic>Otaria byronia</italic> (Péron, 1816) and <italic>Mirounga leonina</italic> (Linnaeus, 1758). We detected positive allometry in <italic>Arctocephalus</italic> for the mastoid width (MW) but negative allometry in <italic>O. byronia</italic> and <italic>M. leonina</italic>. This could indicate that males of <italic>Arctocephalus</italic> exhibited a delayed development of MW. Finally, the presence of common growth trends for the skull length and the postorbital constriction could indicate a conservative pattern within otariids. © 2014 The Linnean Society of London</p> </abstract>