Humans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. Compared to other species,
humans have a highly developed brain, capable of abstract reasoning, language, introspection and problem solving. This mental
capability, combined with an erect body carriage that frees the arms for manipulating objects, has allowed humans to make
far greater use of tools than any other species.
African elephants are the species of elephants in the genus Loxodonta, one of the two existing genera in Elephantidae. Although
it is commonly believed that the genus was named by Georges Cuvier in 1825, Cuvier spelled it Loxodonte. An anonymous author
romanized the spelling to Loxodonta and the ICZN recognizes this as the proper authority. Fossil Loxodonta have only been
found in Africa, where they developed in the middle Pliocene.
Homo erectus is an extinct species of the genus Homo, which originated in Africa and to have spread as far as China and Java.
Amongst scientists it is uncontroversially considered to be a direct ancestor of modern humans. H. erectus originally migrated
from Africa during the Early Pleistocene, possibly as a result of the operation of the Saharan pump, around 2.0 million years
ago, and dispersed throughout much of the Old World.
The Eastern Gray Squirrel (Sciurus carolinensis), or the Grey Squirrel, depending on region, is a tree squirrel native to
the Eastern United States|eastern and midwestern United States and to the southerly portions of the eastern provinces of Canada.
The native range of the Eastern Gray Squirrel overlaps with that of the Fox Squirrel|fox squirrel (Sciurus niger), with which
it is sometimes confused, although the core of the fox squirrel's range is slightly more to the west.
The Thylacine was the largest known carnivorous marsupial of modern times. It is commonly known as the Tasmanian Tiger (because
of its striped back), the Tasmanian Wolf, and colloquially the Tassie (or Tazzy) Tiger or simply the Tiger. Native to continental
Australia, Tasmania and New Guinea, it is thought to have become extinct in the 20th century.
Homo is the genus that includes modern humans and their close relatives. The genus is estimated to be about 2.5 million years
old, evolving from Australopithecine ancestors with the appearance of Homo habilis. Appearance of Homo coincides with the
first evidence of stone tools, and thus by definition with the beginning of the Lower Paleolithic. All species except Homo
sapiens (modern humans) are extinct.
