FORM, FUNCTION AND EVOLUTION OF THE SKULL OF DIDELPHID MARSUPIALS (DIDELPIMORPHIA: DIDELPHIDAE).

AMELIA CHEMISQUY, M.; TARQUINI, SERGIO D.; ROMANO, C.; FRANCISCO J. PREVOSTI

JOURNAL OF MAMMALIAN EVOLUTION

SPRINGER

Lugar: Berlin; Año: 2021

1064-7554

Although didelphid marsupials are considered to have a conservative body shape, they show a considerable amount of size13 variation. They also have different diets (from frugivore to animalivore), but none of the species are specialized. Didelphid14 marsupials also have a certain degree of specialization in vertical habitat use, from ground-dwellers to canopy-dwellers. Several15 authors have shown in other mammals that diet, activity patterns, locomotion, and habitat use influence skull shape in different16 groups of mammals, but also phylogenetic legacy plays a major role in skull evolution. Up till now, there are no published studies17 that investigate the form-function relationship in didelphid skulls; so the aim of this study is to analyze to what extent diet and18 vertical habitat use influence skull shape and override the influence of size and phylogeny. We used 2D geometric morphometry19 data from the skull and by analyzing the phylomorphospace, GLS, and PGLS we studied the effect of diet, vertical habitat use,20 allometry, and phylogenetic legacy on the shape. Our results show that there are almost no shape differences between species of21 different diets and use of the vertical habitat, while allometry shows a strong correlation with shape, and also there is an evident22 effect of the phylogenetic history. As didelphimorphians are not highly specialized, it is possible they developed a more23 generalized skull shape, flexible enough to adapt to different pressures. Moreover, as they have a highly integrated skull with24 few modules, it is expected that they respond to selection pressures by changing their size