Scans of New Hominid’s Skull Find Possible Chunk of Brain—and Bugs
Last week, Lee Berger unveiled for the world the stunningly intact fossils (that his 9-year-old son actually made while with his dad in South Africa) from what he is calling a new hominid species, Australopithecus sediba. Yesterday, he announced another surprise: Berger says that brain scans just finished in France show that insects that might have feasted on the person after death, and even possibly a piece of the hominid’s brain, may be preserved inside the recovered skull.
Experts at the European Synchrotron Radiation Facility (ESRF) in France have been analyzing the find. The ESRF uses a technique known as micro-tomography to assemble its images. This involves taking a series of a high-contrast, high-resolution X-ray radiographs of the target fossil in rotation to build up a 3D representation [BBC News]. The scientists were trying to study the teeth; the skull comes from a young boy, Berger says, and they hoped tooth analysis could help them pin down his exact age at death. But the 3-D representation revealed these other unexpected finds, including a low-density cavity in the skull that could—could—represent a brain remnant.
Soft tissue like the brain, of course, does not usually fossilize. But in this unusual case, ESRF examiner Paul Tafforeau suggests that perhaps the brain shrank after being decayed by bacteria, leaving the odd cavity that his scanners picked up. “One way to explain that cavity is that when this individual died, it was mummified, and the mummification made the brain shrink by losing water, leading to an odd shape,” Tafforeau said. “Later you had water with sediment come up, fossilizing the individual and filling the brain case, but you still had that brain remnant inside” [LiveScience]. If it’s true, the brain remnant is only one-twentieth the size of the original brain, and wouldn’t prove particularly helpful in reconstructing the structure, and unfortunately it’s unlikely DNA would be preserved.
And then there are the insects. Three fossilized insect eggs, each about a tenth of an inch (two or three millimeters) large, were seen within the skull, potentially hatching larvae that fed on the flesh of the hominid after death, researchers added. Two eggs belonged to wasps and apparently had already hatched, while the third, a fly egg, remained unopened [LiveScience]. While Tafforeau says the density would suggest fossil insects, he can’t rule out that they are modern insects that sneaked in until all the data comes in. Both he and Berger are giving few details as their work continues to go through the peer-review process.
Berger also found some fossils from a female Australopithecus sediba he’d like to study in the same way. But for now, the two are traveling separately for security reasons.
Image: European Synchrotron Radiation Facility