Figure 1. Astragali (heel bones) of a condylarth ((a) and (a2)) and anthracobunid ((b) and (b2)) depicting the Tuberculum mediale, a process on the medial side of the bone. This process is one of two proboscidean characters discussed in the text (condylarths are of ungulate stock, believed to have given rise to Proboscidea; anthracobunid are believed by some authors to belong with Proboscidea). Figures (a) and (b) dorsal views, Figures (a2) and (b2) plantar views. Redrawn with permission from Shoshani and Tassy, 1996.

Figure 2. Tooth replacement. Figure 2. Top figures (a), on left are depicted cross sections of a single lamella (plate) of an African elephant. To the right, plates are stacked to form a tooth. Far right figure shows left hemimandible with teeth in place and arrows indicating direction of movements of teeth in the jaw, a feature common to advanced proboscideans. Bottom figures (b) portray five stages of tooth displacement in lower jaws of African elephant. Teeth move on the mandible as if they were on a slow-moving conveyor belt; through time younger teeth are displaced by older ones from behind. As the animal grows older successive cheek teeth become larger and contain more plates. By the time an elephant is about 60 years old, the last molar is worn out. There will be no new tooth to displace it, and the animal is not able to chew its food. It is most likely that it will then die from starvation if not killed by a predator. Redrawn with permission from Shoshani and Tassy, 1996.

Figure 3. Trunk muscles, fascicles, and their functions. Note that there are approximately 150 000 muscle fascicles (portions of muscles) that make up the 16 muscles, 8 on each side. Research by J. Shoshani and G. H. Marchant, artwork by Utako Kikutani; courtesy of Natural History Magazine.

Figure 4. Phylogeny of the Proboscidea. Major trends observed are; increase in size, increase in trunk length, increase in tusk size, and a shift from four (upper and lower) to two tusks, upper only. Research by J. Shoshani, artwork by G. H. Marchant.

Figure 5. A bull African elephant in Amboseli National Park, Kenya. Note the cattle egret by the hind feet; depicting a common sight of egrets following large game in anticipation of insects disturbed by them (photograph by J. Shoshani, courtesy of the American Society of Mammalogists).

Figure 6. Suggested world dispersal patterns and current distribution of the living African and Asian elephants. Note that proboscideans inhabited all the continents except Australia and Antarctica. The figurines on this map are the same as depicted in Figure 4, it is possible therefore to superimpose the scale onto the map. Research by J. Shoshani, artwork by G. H. Marchant.