Publications [#29692] of Damiano Marchi

Papers Presented/Symposia/Abstracts

1. Marchi D, Borgognini Tarli SM, Cross-sectional geometry of Hominoidea by means of biplanar radiography and molding techniques, Folia Primatologica, Supplement 1: 216-217, (2004)
   (last updated on 2007/10/17)

   Abstract:
   Cross-sectional geometric properties (areas, second moments of area) have been extensively used for reconstructing the mechanical loading history of long bone shafts. This study examines cross-sectional geometry (using a moulding technique in combination with biplanar radiography) of metacarpals II-V, metatarsals I-V, and the tibio-fibular complex at 50% length across a sample of chimpanzees, gorillas, orang-utans, and humans. Cheiridia are valuable indicators of positional adaptation in that they directly contact the substrate, while the tibio-fibular complex has been studied to pinpoint the differences linked to locomotor behaviour. All cross-sectional variables were analysed against bone length, body mass, and (body mass x bone length). Reduced Major Axis lines were calculated. ANOVA tests were performed as well as post-hoc comparisons using the Tukey’s honestly significant difference for unequal samples. The “Quick test” and the calculation of the percent prediction error were used to evaluate differences among species. This is the first attempt to study cross-sectional geometry of metacarpals, metatarsals, and tibio-fibular complex within extant hominoids and to shed some light on their relationship with locomotor behaviour. The best results were obtained comparing tibia and fibula, and metacarpals and metatarsals of the same ray. It appears that in more terrestrial as compared to more arboreal hominoids, the tibia is relatively stronger than the fibula. Moreover, in knuckle-walkers metacarpals III and especially IV are relatively stronger than those of the other hominoids, while in humans metatarsal V is relatively stronger than that of the great apes. Interestingly, orang-utans, which perform a quadrumanous arboreal behaviour, have a relative metacarpal IV robustness between the range of knuckle-walkers and that of humans. On the whole, cross-sectional characteristics of the tibio-fibular complex, metacarpal and metatarsal rays are strongly related to the locomotor behaviour of hominoids, and may be useful in elucidating locomotor adaptations of fossil specimens.