Cranial characters associated with the proboscis postnatal-development in Tapirus (Perissodactyla: Tapiridae) and comparisons with other extant and fossil hoofed mammals

MOYANO, SILVANA ROCÍO; GIANNINI, NORBERTO P.

ZOOLOGISCHER ANZEIGER

ELSEVIER GMBH

Año: 2018 vol. 277 p. 143 - 147

0044-5231

Among extant hoofed mammals, only elephants and tapirs exhibita true proboscis. We investigated the development of cranial characterspotentially associated with the presence of a short proboscis in tapirspecies, following a comparative framework with a selection of extant andfossil hoofed mammals that exhibit modified narial structures. The corecharacters present in all taxa (with or without true short proboscis)develop prenatally in tapirs, and other characters that complement theosteological "proboscis syndrome" develop postnatally and are absent orirregularly distributed in other taxa. The taxa examined here showedvarying degrees of cranial modification. On the basis of our comparisons,some fossil taxa are indicated as candidates to have possessed a trueshort proboscis. A terminal addition sequence of character evolution issuggested to explain the development and convergent evolution of theproboscis in hoofed mammals.