This sagittal crest is coupled with another prominent crest oriented across the rear of the skull.These ridges indicate that the chewing muscles and neck muscles were powerfully developed.This principle presumes that the oldest layer of a stratigraphic sequence will be on the bottom and the most recent, or youngest, will be on the top.
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However, that 18,000-year-old date was based on only a geological analysis of the fossils' surroundings and not on direct analysis of the bones themselves.
And the complexity of the cave's geology initially misled the scientists, says Matthew Tocheri, a paleoanthropologist at Lakehead University in Thunder Bay, Ontario, Canada, and a member of the discovery team.
At both localities, the evolutive degree of the associated fossil mammal assemblages allowed a biochronological estimation of the hominid remains: early Pliocene (3–3.5 Ma) at KT 12 and late Miocene (≈7 Ma) at TM 266. This chronological constraint is an important cornerstone both for establishing the earliest stages of hominid evolution and for new calibrations of the molecular clock. Localities investigated in this area include TM 266 and TM 254 (Fig. The Kollé (KL), Kossom Bougoudi (KB), and Koro Toro (KT) fossiliferous areas were specifically studied to calibrate the authigenic Be dating method by direct comparison with biochronological estimations of co-located mammalian assemblages.
Fossiliferous localities investigated in these areas were KL, KB 1, and KT 12 (Fig. KT 12 (16°00′N, 18°53′E) is the site of locality, Toros-Menalla, Upper Miocene, Northern Chad).
The base of the mapped sections consists of a well developed, thick, aeolian facies (8). U.) is composed of poorly cemented sand and argillaceous sandstone alternation characterized by dense networks of root tubules/root molds (palaeosols) and termite nests (9, 10). The uniform stratigraphy at the TM localities allowed us to use absolute ages from both TM 266, where Toumaï was discovered, and TM 254 to assign an age to Toumaï.
It was hoped that the tephra layer would contain material datable by the Be associates with continental particles, where it decays with a half-life of ≈1.4 million years.Because some of the bones are crushed and distorted, however, the face and braincase are warped. As in the case of OH 16, this specimen had been broken into many fragments, which could be collected only after extensive sieving of the deposits.Some of the pieces were then fitted into the reconstruction of a face and much of a large vault.Now, many of the same scientists who made the discovery have radically revised their estimate of the fossils' age, based on an exhaustive new analysis of the cave’s geology.Instead of living 18,000 years ago, as they originally reported, the hobbit lived between 60,000 and 100,000 years ago—some 10,000 years before makes it “impossible to argue that it is a pathologically-dwarfed modern human,” says Russell Ciochon, a paleoanthropologist at the University of Iowa in Iowa City who was not involved in the study.“In my opinion, this paper drives the final nail in the coffin” of that hypothesis.