The Toumai Fossil
Scientists called anthropologists study the history of humans
and how humans have developed over time. Some
anthropologists study fossils of human ancestors to figure out
how humans have evolved or changed. Evolution takes long
periods of time, and fossils are all that remain of the extinct
species that came before humans. When a species is extinct, it
no longer exists. Anthropologists have found many fossils of
extinct, human-like species and have begun to figure out a
timeline of human evolution.
An Unusual Discovery
In 2001, scientists discovered an unusual fossil of a skull. This
skull was an important find because the skull belongs to a
species of ape that had not yet been seen. The skull is unusual
because the face of this skull is flat, like that of modern humans.
The part of the skull that holds the brain, however, is small, like
a chimpanzee.
The scientific name of this fossil is
Sahelanthropus tchadensis. The
scientists who discovered the fossil
gave the fossil the nickname
"Toumai." Toumai was discovered in
the country of Chad in Central Africa
and is the oldest fossil of a humanlike species ever found. In fact, the
fossil is between 6 and 7 million
years old. Before Toumai was
discovered, another famous fossil,
nicknamed Ardi, was the oldest
human-like fossil ever found. Ardi is
Older hominid skull fossils have a more sloped face and
4.4 million years old. Toumai is
smaller brain case. More recent hominid skull fossils have
almost twice as old as Ardi, which was a flatter face and larger brain case.
a surprise to anthropologists.
Controversy Over the Toumai Fossil
Humans and their human-like ancestors belong to a group
called hominids. Anthropologists study the skulls of hominids to
understand how extinct species evolved into modern-day
humans. When observing skull fossils, anthropologists noticed
certain trends. The older the skull, the more sloped the face and
the smaller the brain case (the area in which the brain sits).
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The Toumai Fossil
Skulls of hominids that lived more recently tend to have a flatter
face and larger brain case. Having a larger brain case allowed
more modern hominids to develop bigger brains and higher
levels of intelligence.
The Toumai fossil does not fit into this
trend. The Toumai fossil has a flat face
but a small brain case. In addition, the
fossil is much older than any of the
other hominid fossils ever found. These
facts make Toumai a very interesting
fossil to study. Since the discovery of
the Toumai fossil, anthropologists have
been debating how the fossil fits into
the history of human evolution. The flat Modern chimpanzees have a more sloped
face suggests that Toumai is a human
face and smaller brain case than modern
ancestor. The team of people who found humans.
the fossil also considered Toumai to be a
human ancestor. Other scientists argue that Toumai is a
chimpanzee ancestor.
Chimpanzees are the closest living relatives of modern humans.
Evidence from fossils suggests that, at some point, the ancestors
that led to humans branched off from the ancestors that led to
chimpanzees. Chimpanzees, and all of their extinct ancestors,
have a sloped face and smaller brain case. The smaller brain
case of Toumai suggests it is a chimpanzee ancestor.
The Toumai fossil is very important because this fossil could
change how anthropologists understand human evolution.
Toumai may provide evidence that other fossils are not
ancestors of humans. The skull may also provide information to
help scientists figure out how humans and chimpanzees from
long ago branched off from each other.
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