Can you imagine an ape the size of your cat?
Scientists have discovered a fossilized molar that belonged to the smallest species of ape ever to have existed, Simiolus minutus.
They estimate that an individual of this species weighed approximately eight pounds, or slightly less than the average house cat, and roamed the Earth approximately 12.5 million years ago.
How is a tooth proof of a new species?
Scientists based their identification of this new species on the discovery of three fossilized teeth.
Fossils are formed from the remains of an organism. When the organism dies, its skeleton is buried by sediment which eventually thickens and compacts to turn to stone. Over a long period of time, the original form from the animal breaks down, just leaving the molded stone. Minerals then enter the mold and crystalize creating a replica of the original organism's form.
The fossilized teeth found in Kenya were not compatible with any other known species of ape, leading scientists to come to the conclusion that they originated from a species that had yet to be discovered.
What happened to this small species of ape?
You probably would have heard of a miniature ape if it still existed. The Simiolus minutus has been extinct for millions of years, meaning that some pressure caused all individuals of the species to die off.
There are two types of extinction. You have probably heard of mass extinction in which some environmental event kills large numbers of a species, for example, a meteor wiping out the dinosaurs. There is also what is called background extinction, in which species naturally go extinct as a result of natural selection driven by competition.
Natural selection is a process that drives the evolution of species that is best suited for their environment. Within a species, there is genetic variation that makes it more likely that certain individuals will reproduce and pass on the advantageous characteristics to their offspring. Natural selection only occurs when there is a pressure present, such as competition for limited resources.
Based on the characteristics of the fossilized teeth, scientists believe that the Simiolus minutus survived off of a diet mainly of leaves and fruit. The estimated age and geographic location of the species suggest that the Simuilus minutus was likely in competition with colobine monkeys for food resources. It is hypothesized that ultimately, this competition resulted in the thriving of colobine monkeys and extinction of the Simiolus minutus, as colobine monkeys were able to more effectively compete for food.
Sources: LiveScience, NYTimes, Britannica, Howstuffworks, study.com