I've recently returned from the annual meeting of the American Association of Physical Anthropologists in Columbus, OH., and if there was one word that was on everyone's lips, it was hobbits. OK, maybe not everyone. There were plenty of attendees who study nonhuman primates and human genetics, among other topics, and probably have at most a glancing interest in the tiny remains from Flores, Indonesia, that have been held up as a new species of human, Homo floresiensis. But of the presentations I attended, it was the hobbit-related talks that drew standing-room only crowds

I'm working on a story that will discuss some of the findings presented at the meeting. But in addition to the formal talks there was some interesting hallway scuttlebutt. Hobbit skeptic Maciej Henneberg is proposing that the skeleton known as LB1—the most complete hobbit by far—appears on the basis of photographs to have had a filling, possibly a root canal, in its lower left first molar (the M1). If true, this would mean the hobbit is a modern human, not a new species, which is the minority viewpoint that Henneberg and his colleagues have been arguing all along.

Henneberg showed a series of photographs that appear to support his argument. He made the observations in 2005, but was waiting to get access to the original bones so that he can verify what he thinks he sees in the photos before publishing his theory. Because he doubts that he will receive permission to examine the remains, however, he is now circulating his idea.

Suffice it to say, I was eager to hear how other hobbit researchers would respond. Both sides tend to be dismissive of each other's work, so I expected there would be strong words from the hobbit defenders. And there were. But they backed up their position with CT scans and photographs.

In the photo below, LB1's lower jaw appears on the right and a second mandible from the same site is on the left. Here's what Peter Brown of the University of New England, who led the initial analysis of LB1 and supplied both this photograph and the CT scan, said about the surface of the M1:

"The photograph of the occlusal surface shows there is no filling. There are no dental materials or dentists who can color match and hide a cavity in a molar to the degree that would be necessary. Why would anyone want to, even if possible. Certainly not with the dental amalgam which was all that was available until fairly recently."


PETER BROWN University of New England

(Click on photo links at the top of this post to see full size images.)

Next up is the CT scan, in which the normal, bifurcating roots of the M1 are visible. According to Brown, "…the CT scans when combined with the detailed occlusal view, totally refute Henneberg's claim."


PETER BROWN University of New England

(Click on photo links at the top of this post to see full size images.)

I then contacted Charles Hildebolt of Washington University, who has also been working on the Flores material and has obtained his own CT scans. He had this to say in an e-mail:

"We think that it is highly unlikely that any type of filling material is in the mandibular left first molar. The defect in the mandibular left first molar does not have the appearance of a cavity preparation made by a dentist in that the defect is shallow, is non-retentive, and is not extended in an apical direction interproximally. There is no indication of tooth decay in any of LB1’s teeth. Silver amalgam fillings were present in the 1930s, and if a dentist were to place a filling in a tooth, it would seem most likely that it would be a silver amalgam. If for some reason, a temporary filling were placed in LB1’s mandibular left first molar, we should be able to see some indication of it in the CT images, but we cannot—all that we can see is a defect that resembles other defects on LB1’s teeth where the enamel has worn away and the dentine is exposed."

We'll see how the skeptics respond. But you can be certain that even if the dental work hypothesis is disproved scientists will continue to debate whether the little Floresians represent a new human species or not.


Update 4/16/08: Paleoanthropologist John Hawks has posted his own take on this story and goes into detail about why Henneberg thinks the hobbit had dental work done.

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Edited by Christie Nicholson at 04/17/2008 1:38 PM