EVOLUTION OF MOLAR SHAPE IN DIDELPHID MARSUPIALS: ANALYSIS OF THE INFLUENCE OF ECOLOGICAL FACTORS AND THE PHYLOGENETIC LEGACY

CHEMISQUY, M. A.; FRANCISCO J. PREVOSTI; GABRIEL MARTIN; FLORES, D.

ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 173 p. 217 - 235

0024-4082

The diversity of items consumed by modern didelphids, varying from mostly fruits in Caluromys Allen to mostlysmall vertebrates in Lutreolina O. Thomas, may cause changes in molar size and shape. We evaluated the morphometricvariation of the first and third upper and lower molars of 16 genera of didelphid marsupials, with the aim ofassessing the relationship between molar shape change, diet and phylogeny. We used a geometric morphometricapproach to analyse how shape changes with diet. We mapped shape onto the phylogeny of the group to reconstructancestral states and analyse the evolution of molar shape. Finally, we statistically estimated the effect ofsize, diet and phylogeny on molar shape. All the analyses indicated little correlation between diet and molar shapeand a strong correlation between the position of each genus on the phylogeny and molar shape. We believe thatthe wide ecological niche used by most of the groups (at least regarding diet) makes the evolutionary changes notstrong enough to override pre-existing differences that occur among clades, and the absence of highly dietspecializedspecies (e.g. hypercarnivory or obligate folivory) causes the need for retaining a molar shape that canbe useful to process different kinds of food items.