The vomeronasal organ (VNO) is a chemosensory structure of the nasal septum found in most tetrapods. Although potential behavioural correlates of VNO function have been shown in two of the three elephant species, its morphology in Loxodonta africana has not been studied. The development of the VNO and its associated structures in the African elephant are described in detail using serially sectioned material from fetal stages. The results show that many components of the VNO complex (e.g.
The tusk of the African elephant is preceded by a deciduous tooth generally known as the tush. Tushes from nine elephant fetuses and six calves younger than 1 year were exposed by dissection and described morphologically. All tushes consisted of a crown, root and pulpal cavity, the formation of which is completed soon after birth. They reached a maximum length of 5 cm, appeared not to erupt through the skin and were pushed aside and resorbed during enlargement of the distally located primordium of the tusk.
The dentition of an elephant (fossil or extant) can yield clues to the animal's age and identity, provided the teeth are correctly identified. Identifying the serial category of elephant teeth is difficult, because the size, shape and position of each tooth changes throughout life, as the teeth form, erupt, wear and move through the jaw. In the present study, teeth from over 100 museum specimens of the Asian elephant (Elephas maximus) were the basis for establishing size ranges for cheek teeth in six serial categories (designated by Roman numerals I to…
At the morphological level, the woolly mammoth has most often been considered as the sister-species of Asian elephants, but at the DNA level, different studies have found support for proximity with African elephants. Recent reports have increased the available sequence data and apparently solved the discrepancy, finding mammoths to be most closely related to Asian elephants. However, we demonstrate here that the three competing topologies have similar likelihood, bayesian and parsimony supports.
The narrow- and wide-gauge trackways attributed to sauropod dinosaurs are hypothesized to be a consequence of the relative positions of their centers of mass. This hypothesis was tested using three-dimensional, trackwayproducing computer models of two sauropods and studies of Asian elephants. Centers of mass of sauropod models were computed using density distributions that reflect the high degree of pneumatization of the skeletons and air sacs within the body.