Skip to main content

Skull allometry and sexual dimorphism in the ontogeny of the southern elephant seal (Mirounga leonina)

Buy Article:

$50.00 plus tax (Refund Policy)


The southern elephant seal (Mirounga leonina (L., 1758)) is one of the most dimorphic mammals, but sexual dimorphism in its skull ontogeny is poorly known. We study ontogeny of sexual dimorphism by the allometric relationships between 21 measurements and its geometric mean. Based on 66 specimens (36 females, 30 males), the bivariate and multivariate analyses indicated that both approaches were congruent in most variables. We detected that sexual dimorphism was reached mostly by sexual shape differences in the ontogenetic trajectories of males and females. Twenty-four percent of variables were associated with intercept differences (pup size proportions), while 57% of variables were associated with slope intersexual differences (relative growth rates). Contrarily, sexual dimorphism was also achieved by size differences in adult stages (19% of variables), as males exhibited an extension of their common ontogenetic trajectories. Secondary growth spurt in males was detected for few variables. Our comparison with analogous data collected from southern sea lions (Otaria byronia (de Blainville, 1820)) indicated that in both species, sexual dimorphism was mostly associated with an enhanced ability to defend territories, which was linked to the polygynic behavior. However, discrepancies between both ontogenetic patterns of dimorphism were associated with interspecific differences in their life cycles.

Keywords: Mirounga leonina; Otaria byronia; allometric growth; cranium; croissance allométrique; crâne; growth rate; morphometry; morphométrie; otarie à crinière; pinniped; pinnipède; southern elephant seal; southern sea lion; taux de croissance; éléphant de mer austral

Document Type: Research Article


Affiliations: División Mastozoología, Museo Argentino de Ciencias Naturales, “Bernardino Rivadavia” CONICET, Avenida Ángel Gallardo 470, C1405DJR Ciudad Autónoma de Buenos Aires, Argentina.

Publication date: January 1, 2014

More about this publication?
  • Published since 1929, this monthly journal reports on primary research contributed by respected international scientists in the broad field of zoology, including behaviour, biochemistry and physiology, developmental biology, ecology, genetics, morphology and ultrastructure, parasitology and pathology, and systematics and evolution. It also invites experts to submit review articles on topics of current interest.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • ingentaconnect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more