An ancient tooth dating back 13 million years was discovered in the northern part of India and it belonged to a previously unknown ape species called Kapi ramnagarensis. In fact, it is the first new ape species unearthed at the Ramnagar site in about a century.
Additionally, it was the earliest known ancestor of today’s gibbon which answers some questions as to when they migrated from Africa to Asia. Gibbons are omnivores that can live up to 25 years in the wild. Their long coats can be cream, brown, or black in color, with many of them having white markings on their face, hands, and feet. These small tailless apes grow between 17 to 25 inches (1.4 to 2 feet) and weigh between 9 and 29 pounds (4 to 13 kilograms).
This is quite significant as it fills in an important gap in the fossil records of ancient apes. The discovery was made by Christopher C. Gilbert from Hunter College when he found a complete lower molar belonging to the Kapi ramnagarensis species. When he and other members of his team (Chris Campisano, Biren Patel, Rajeev Patnaik, and Premjit Singh) were climbing a hill, they stopped to take a break when Gilbert noticed something shining within a pile of dirt and that’s when he noticed the molar. The location had special significance as an ancient primate jaw was found there just one year ago.
“We knew immediately it was a primate tooth, but it did not look like the tooth of any of the primates previously found in the area,” Gilbert explained, adding, “From the shape and size of the molar, our initial guess was that it might be from a gibbon ancestor, but that seemed too good to be true, given that the fossil record of lesser apes is virtually nonexistent. There are other primate species known during that time, and no gibbon fossils have previously been found anywhere near Ramnagar. So we knew we would have to do our homework to figure out exactly what this little fossil was.” (A scan of the tooth can be seen here.)
The molar was found in 2015 and extensive studies have since been conducted on it, concluding that it belonged to previously unknown species. Alejandra Ortiz who was a member of the research team, stated, “What we found was quite compelling and undeniably pointed to the close affinities of the 13-million-year-old tooth with gibbons,” adding, “Even if, for now, we only have one tooth, and thus, we need to be cautious, this is a unique discovery. It pushes back the oldest known fossil record of gibbons by at least five million years, providing a much-needed glimpse into the early stages of their evolutionary history.”
In regards to when they migrated from Africa to Asia, Campisano went into details, “Today, gibbons and orangutans can both be found in Sumatra and Borneo in Southeast Asia, and the oldest fossil apes are from Africa. Knowing that gibbon and orangutan ancestors existed in the same spot together in northern India 13 million years ago, and may have a similar migration history across Asia, is pretty cool.”
Their study was published in the Proceedings of the Royal Society B and can be read in full here.