capítulos de libros
Diversity of craniomandibular morphology in caviomorph rodents. An overview of macroevolutionary and functional patterns
ALVAREZ, ALICIA; VIEYTES, E. CAROLINA; BECERRA, FEDERICO; OLIVARES, A. ITATÍ; ECHEVERRÍA, ALEJANDRA I. ; VERZI, DIEGO H.; VASSALLO, ALDO I.
Biology of caviomorph rodents: diversity and evolution
Sociedad Argentina para el Estudio de los Mamíferos SAREM
Lugar: Mendoza; Año: 2015; p. 1 - 50
Caviomorphs are abroadly diversified rodent clade. Accordingly, a great morphological disparityhas been detected. This variation bears a clear phylogenetic signal, and astrong allometric component was also detected. Morphological variation isassociated with the habitat occupied by each species, with the most divergentcondition seen in species with burrowing habits. These species present amassive skull associated with strong masticatory musculature and a stabilizedtemporomandibular joint that allows the generation of high bite forces. Thesefeatures are present in species that use incisors in digging or in aggressiveencounters during courtship or territorial defense, as in the case of Ctenomys.Exertion of higher bite forces also influences dental morphology and enamelmicrostructure. Procumbent incisors, deeply implanted, with high resistance toflexion-torsion forces, are observed in species that display the aforementionedfeatures. Features with opposite trait values are present in species thatexhibit lower bite forces. With respect to the molar enamel microstructure, ageneralized pattern linked to brachydont teeth can be observed; by contrast, asecondary gradual acquisition of radial enamel is related to the acquisition ofhypsodonty, strengthening the enamel band and favoring the formation of sharpedges. The strong phylogenetic signal of morphological variation observedamong extant caviomorphs may be explained by an early establishment of themajor pathways of craniomandibular specialization in the evolutionary historyof these rodents. However, phylogenetic structure alone does not explainmorphological changes. Several variables such as size, habitat, diet, habits,and diverse aspects of the life history of species, such as burrow constructionand social interaction are also linked to the observed morphological variation.The integration of macroevolutionary and morpho-functional studies in futurecomprehensive studies that involve both approaches, together withpaleoenvironmental inferences, would improve the understanding of the evolutionof this exceptional group of rodents.