"It’s A Nose! It’s A Hand! Its An Elephants’ Trunk!"
Natural History, November 1997, Volume 106, number 10, pp.37-43
This article, written by renowned elephant-lover Jeheskel Shoshani, discusses the evolution of the proboscidean lineage, with great emphasis upon the development of the trunk feature, along with a discussion of the appendage’s many uses.
The earliest ancestors of today’s elephants lived more than fifty-five million years ago, and were the size of small pigs. They were, for the most part, probably without trunks, but might have had a mobile upper lip, somewhat similar to the present-day tapir. Evolution began a trend toward larger proboscideans. Among the adaptations were larger bodies, larger heads, and larger, more elongated mandibles(jaws). As a result, natural selection tended to favor the biggest, strongest, and most well-adapted creatures. As the head and jaws continued to become more elongated, (so that reaching food at high levels was possible), the animals had much difficulty keeping control of these awkwardly heavy appendages. Natural selection, evolution and adaptation provided the obvious solution. The head and jaws became shorter and less cumbersome, and the snout combined with the upper lip to form what developed into what we now call the "trunk." In more primitive species, the trunk began to form and situate itself lower on the cranium, whereas modern elephant’s trunks are placed between or slightly above the eyes. It is widely assumed that as recently as seven million years ago, some species of proboscideans had fully developed "trunks" similar in size, appearance and function to those of today’s elephants.
The author of this article established the Elephant Research Foundation in 1977, and continues to gather information and study all aspects of all proboscideans, living and extinct, in captivity and in the wild.
In modern elephants, the trunk begins developing in utero. The snout and lip unite, and the formation of this fabulous appendage is officially underway. Young elephants are very clumsy with their trunks (which are not usually full size in terms of proportion to the body until 1year of age), as it takes much time to master the sophisticated "arm" of sorts. The elephants have an extremely keen sense of smell (remarkably better than that of the domesticated dog, for example). The trunks of different elephants are designed and adapted differently. There are distinct differences between the snout of a wooly mammoth, the African elephant, and the Asian elephant. For example, the African elephant has extra folds of skin on its trunk for extra stretching ability, whereas the Asian elephant does not. The trunks can siphon up to 2.7 gallons of water at a time, and function as very convenient and flexible showerheads!
The trunk seems to be infinitely useful in helping these modern-day wonders to conquer the elements and survive in this harsh world. Necessity told these creatures’ genetic make-up that something had to be done in order to help them thrive and avoid extinction. Evolution had the logical solution…the trunk!