In Photos: 13-Million-Year-Old Primate Skull Discovered

Napudet site

Discovery site at Napudet, west of Lake Turkana, Kenya. The red flag marks where Alesi was found. — (Image credit: © Isaiah Nengo)

A 13-million-year-old skull of an extinct ape was discovered at a site called Napudet (shown here), west of Lake Turkana in Kenya in 2014. Now, the primate skull is revealing what the last common ancestor of all living apes and humans may have looked like. Apperently, this primate dubbed "Alesi" would have resembled a baby gibbon. [Read the full story on Alesi]

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Field crew of the Turkana Basin Institute when Alesi was discovered at Napudetin September 2014. — (Image credit: © Isaiah Nengo)

The field crew of the Turkana Basin Institute is shown here when Alesi was discovered at Napudet in September 2014. From Left to right: Abdala Ekuon, John Ekusi, Isaiah Nengo, Bernard Ewoi, Akai Ekes, and Cyprian Nyete.

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Cyprian Nyete (left) and Isaiah Nengo (right) excavating Alesi, using fine picks and brushes, as well as a hardener to protect the fossil bone. — (Image credit: copyright Isaiah Nengo)

Cyprian Nyete (left) and Isaiah Nengo (right) excavate Alesi, using fine picks and brushes, as well as a hardener to protect the fossil bone.

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Alesi partially excavated after careful removal of loose sand and rocks with dental picks and brushes. — (Image credit: Copyright Isaiah Nengo)

Alesi is shown partially excavated after careful removal of loose sand and rocks with dental picks and brushes. The primate would have been just 16 months old when it died.

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Akai Ekes and John Ekusi watch as Isaiah Nengo lifts the sandstone block with Alesi, after six hours of excavation.

Alesi after attached sandstone rock was partially removed at the Turkana Basin Institute, near Lodwar, Kenya. — (Image credit: Copyright Isaiah Nengo/Photo by Christopher Kiarie)

Alesi's lemon-size skull, shown after attached sandstone rock was partially removed, still had the roots of baby teeth.

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Alesi, the skull of the new extinct ape species. — (Image credit: Copyright Fred Spoor)

From Alesi's teeth, the researchers concluded that the primate would have been a fruit eater. The researchers couldn't tell if Alesi was male or female, since the primate was too young for sex-related skull features to have formed, the researchers said.

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Alesi, the skull of the extinct ape species. — (Image credit: Copyright Fred Spoor)

As an adult, the primate would have weighed about 24.9 lbs. (11.3 kilograms), with a brain about as big as that of a modern lemur of the same size, the researchers said.

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Experimental setup at the European Synchrotron Radiation facility,used for the high resolution X-ray scanning of Alesi. The skull is mounted on a rotation stage in front of the detector, and a laser beam is used for accurate alignment. — (Image credit: Copyright Paul Tafforeau)

The researchers scanned Alesi with a high-resolution X-ray setup at the European Synchrotron Radiation facility. The skull was mounted on a rotating platform in front of the detector, and a laser beam is used for accurate alignment.

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Map of Africa and Kenya, showing the location of Napudet, where Alesi was found. [Read the full story on Alesi]

Jeanna Bryner is managing editor of Scientific American. Previously she was editor in chief of Live Science and, prior to that, an editor at Scholastic's Science World magazine. Bryner has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species, including the gorgeous Florida Scrub Jay. She also received an ocean sciences journalism fellowship from the Woods Hole Oceanographic Institution. She is a firm believer that science is for everyone and that just about everything can be viewed through the lens of science.