Biomedical subjects

N Toth

Publications and source records attributed to N Toth.

4 recordsLinked to original sources

PubMed2000

Brief communication: cutmarks on a plio-pleistocene hominid from Sterkfontein, South Africa.

Cutmarks inflicted by a stone tool were observed on the right maxilla of Stw 53, an early hominid partial skull from Sterkfontein "Member 5" (South Africa). The morphology of the marks, their anatomical placement, and the lack of random striae on the specimen all support an interpretation of this linear damage as cutmarks. The location of the marks on the lateral aspect of the zygomatic process of the maxilla is consistent with that expected from slicing through the masseter muscle, presumably to remove the mandible from the cranium. Although radioisotopic dates are not available and relative faunal dating of the deposit from which Stw 53 derives is problematic, the morphology of the hominid skull suggests a Plio-Pleistocene age for the specimen. This therefore constitutes the earliest unambiguous evidence that hominids disarticulated the remains of one another.

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PubMed1998

EMG study of hand muscle recruitment during hard hammer percussion manufacture of Oldowan tools.

The activity of 17 hand muscles was monitored by electromyography (EMG) in three subjects during hard hammer percussion manufacture of Oldowan tools. Two of the subjects were archaeologists experienced in the replication of prehistoric stone tools. Simultaneous videotapes recorded grips associated with the muscle activities. The purpose of the study was to identify the muscles most likely to have been strongly and repeatedly recruited by early hominids during stone tool-making. This information is fundamental to the identification of skeletal features that may reliably predict tool-making capabilities in early hominids. The muscles most frequently recruited at high force levels for strong precision pinch grips required to control the hammerstone and core are the intrinsic muscles of the fifth finger and the thumb/index finger regions. A productive search for skeletal evidence of habitual Oldowan tool-making behavior will therefore be in the regions of the hand stressed by these intrinsic muscles and in the joint configurations affecting the relative lengths of their moment arms.

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PubMed1989

Engis: preparation damage, not ancient cutmarks.

Scratches found on the Engis 2 cranium have been described as perimortem and interpreted as intentional scalping marks by Russell and LeMort (Am. J. Phys. Anthropol. 69:317-323, 1986). These marks are described and compared to damage on other fossil hominids. The Engis marks have been misinterpreted. These marks are sandpaper striae formed during restoration of the vault, moulding striae formed when mold part lines were incised into the fossil and profiling striae formed when craniograms were made with sharp steel instrument tips. None of them have anything to do with prehistoric behavior.

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PubMedDate not supplied

ESR dating tooth enamel from the Paleolithic site at Longola, Zambia.

A single radiation-sensitive ESR signal at g = 2.0018 occurs in fossil tooth enamel, but not in modern teeth. In dating fossil teeth, the equivalent radiation dose (AD) needed to produce the observed ESR signal is the integral with respect to time of the natural, environmental dose rate (ED) experienced by the tooth during burial. Since the age depends on the U uptake history assumed, three dates are normally calculated assuming early U uptake (EU), continuous (linear) U uptake (LU), or recent U uptake (RU). Generally the LU ages agree best with known ages determined by other methods, but the EU and RU ages are respectively the minimum and maximum ages. Longola Spring Mound, in Central Zambia, contains a Late Stone Age collection occurs on the mound surface. Embedded in layer near the base is a much older layer containing Middle Stone Age artifacts and bone material. Four ungulate teeth collected from the lower layer were ESR dated. EU, LU, and RU ages for each tooth agree very closely, but ages range from 14 to 96 ka. Although the layer may be a two component deposit with teeth averaging 18 +/- 2 ka and 91 +/- 3 ka, high sedimentary Th concentrations and ESR isochrons suggest that gamma ext dose estimates are in error. LU dates estimated from isochron plots average 204 +/- 86 ka, while LU ages calculated with the average isochron-derived gamma ext = 10.79 +/- 1.89 mrad/a average 220 +/- 62 ka. More excavation and dating are necessary to determine if the isochron data is reasonable.(ABSTRACT TRUNCATED AT 250 WORDS)

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