Educational elephant centric information plus fun and games.

Elephant Evolution

Zoological Classification

Elephant comes from the Greek word "elephas" meaning ivory. This, of course, refers to their tusks. In scientific nomenclature, elephants belong to the order Proboscidae. This word is also Greek referring to the other distinctive elephant anatomy, the trunk.

In understanding elephant evolution, I think we should first discuss zoological nomenclature. In science, animals and plants are classified and named using a universal system and language. At the narrowest or top level is the genus and species. Every animal and plant can be identified by its two-word (genus and species) name. (i.e. Homo sapiens: man).  When subspecies are present, this can be a three-word name. (i.e. Elephas maximus maximus: Sri Lankan Asian elephant). If you think of species denoting one kind of animal or plant, then genus would include more than one kind. From the top level to the bottom level the number of animals or plants included in each group increases. In general the major categories of classification listed from top to bottom or low to high are:

Keep in mind, between these major levels are usually even further divisions. (i.e. Superfamily or Suborder).

Below is a simple classification of our modern day elephants.

• Kingdom: Animalia
  • Phylum: Chordata
    • Class: Mammalia (mammals)
      • Subclass Eutheria (Placental mammals)
        • Order: Proboscidae
          • Family: Moeritheriidae
            • Genus: Moeritherium
          • Family: Palaeomastodontidae
            • Genus: Palaeomastodon
          • Family: Gomphotheriidae
          • Family: Mammutidae
            • Genus Mammut (mastodons)
          • Family: Elephantidae
            • Genus: Primelephas
            • Genus: Mammuthus (mammoths)
            • Genus: Elephas
              • species: maximus (Asian elephants)
            • Genus: Loxodonta
              • species: cyclotis (African forest elephants)
              • species: africana (African savanna elephants)

Classification problems

One of the major criteria for grouping animals in one classification or another is anatomy (bone and teeth structure). This is so because of their durability. The tusks of elephants evolved from enlarged incisor teeth. Most other tusked mammals formed them from canines. This among other characteristics helps identify the elephant's ancestors and relatives. The discovery of new fossils and the use of new scientific techniques could influence the classification of some species considerably.

Although its not a hard and fast rule, in general, the characteristics that distinguishes one classification from another should be true, as a whole, for all members of and below that classification, extinct and extant (living). These distinguishing characteristics should not be true, as a whole, for members outside or above the classification.

Subclass Eutheria

Among the orders emanating from the subclass Eutheria are three that are closely related scientifically.

Order Hyracoidea:

Modern descendants are the hyraxes. African rodent-like animals the size of rabbits.

Order Sirenia:

Modern descendants are manatees and dugongs (sea cows). Seal-like mammals living entirely in water.

Order Proboscidea:

The order of modern elephants.

Scientists, after studying the anatomical and morphological data, have concluded that these three orders share a common ancestor. Despite the differences in appearance and habitat, today it is agreed that the closest living relatives to modern elephants are the hyraxes and sea cows!

Order Proboscidea

Proboscidea, a Greek word, means having a proboscis, or nose. Over 50 million years, it has been determined that there have been over 350 species of proboscideans. These animals inhabited every continent of the world, except for Antarctica and Australia. Today there are only three major species left; Asian, African savanna, and African forest elephants.

Moeritherium (extinct)

Moeritherium, pronounced mee-ri-THEER-ee-um, is the earliest known member of the order Proboscidea. The first fossils were discovered in 1904 at El Faiyum oasis in Egypt. This oasis was known as Lake Moeris in ancient Egypt Moeritherium fossils showed the beginnings of enlarged incisors (tusks) but there is no evidence of a trunk. They lived about 50 million years ago with a hippo-like lifestyle. In fact, they have been described as pygmy hippopotami. They were about the size of a pig standing 70cm at the shoulders with stout elephantine legs and a long body.