A geometric morphometric approach to airorhynchy and functional cranial morphology in Alouatta (Atelidae, Primates) Export

@article{citeulike:2618015, abstract = {The skull of the howler monkeys (Alouatta spp., Atelidae) is characterised by a generalised rotation of the splanchnocranium with respect to the neurocranial antero-posterior axis. This process, referred to as airorhynchy, is the result of a derived structural relationship between basicranium, vault, and facial districts. A number of variables – such as diet and social behaviour – probably co-evolved with the remodelling of the cranial functional matrix. We used a landmark-based analysis to explore the geometri- cal model of the skull in the genus Alouatta. Shape comparisons were performed by using superimposition procedures and the Euclidean distance matrix. In the latter analysis, a method is proposed in order to visu- alise variations of form through chromatic maps and interpolant functions. The comparison with other gen- era of Atelidae shows a marked neurocranial flattening in Alouatta as well as muzzle projection and enlargement, nuchal flattening, relative basicranial lengthening, and tilting of the occipital foramen. Only minor differences were visible in relation to facial shape, suggesting that significant changes depend on the relationship between splanchnocranium and neurocranium, rather than on localised anatomical variations. The limited vault development constrained by the basicranial structures probably involved the extreme retroflexion of the basal angle. Airorhynchy can be interpreted as an additional adjustment to fit this struc- tural network beyond the biomechanical range of the cranial base hypoflexion. This cranial functional matrix is directly related to feeding and social changes, representing an interesting evolutionary ” package”. In Pongo pygmaeus a similar process is associated with a different structural pattern, mostly related to the flattening of the upper facial structures, maxillary midsagittal enlargement, and palatal tilting.}, author = {Bruner, Emiliano and Mantini, Simone and Manzi, Giorgio}, citeulike-article-id = {2618015}, citeulike-linkout-0 = {http://www.isita-org.com/jass/Contents/2004%20vol82/Bruner_47_66%5b1%5d%5b1%5d.qxd.pdf}, journal = {Journal of Anthropological Sciences}, keywords = {airorhynchy, alouatta, analysis, craniology, distance, euclidean, functional, geometric, matrix, morphometrics, pongo}, month = {August}, pages = {47--66}, posted-at = {2008-04-01 01:24:33}, priority = {2}, publisher = {Istituto Italiano di Antropologia}, title = {A geometric morphometric approach to airorhynchy and functional cranial morphology in Alouatta (Atelidae, Primates)}, url = {http://www.isita-org.com/jass/Contents/2004%20vol82/Bruner_47_66%5b1%5d%5b1%5d.qxd.pdf}, volume = {82}, year = {2004} }

TY - JOUR ID - citeulike:2618015 L3 - citeulike-article-id:2618015 N2 - The skull of the howler monkeys (Alouatta spp., Atelidae) is characterised by a generalised rotation of the splanchnocranium with respect to the neurocranial antero-posterior axis. This process, referred to as airorhynchy, is the result of a derived structural relationship between basicranium, vault, and facial districts. A number of variables – such as diet and social behaviour – probably co-evolved with the remodelling of the cranial functional matrix. We used a landmark-based analysis to explore the geometri- cal model of the skull in the genus Alouatta. Shape comparisons were performed by using superimposition procedures and the Euclidean distance matrix. In the latter analysis, a method is proposed in order to visu- alise variations of form through chromatic maps and interpolant functions. The comparison with other gen- era of Atelidae shows a marked neurocranial flattening in Alouatta as well as muzzle projection and enlargement, nuchal flattening, relative basicranial lengthening, and tilting of the occipital foramen. Only minor differences were visible in relation to facial shape, suggesting that significant changes depend on the relationship between splanchnocranium and neurocranium, rather than on localised anatomical variations. The limited vault development constrained by the basicranial structures probably involved the extreme retroflexion of the basal angle. Airorhynchy can be interpreted as an additional adjustment to fit this struc- tural network beyond the biomechanical range of the cranial base hypoflexion. This cranial functional matrix is directly related to feeding and social changes, representing an interesting evolutionary “package”. In Pongo pygmaeus a similar process is associated with a different structural pattern, mostly related to the flattening of the upper facial structures, maxillary midsagittal enlargement, and palatal tilting. JF - Journal of Anthropological Sciences EP - 66 TI - A geometric morphometric approach to airorhynchy and functional cranial morphology in Alouatta (Atelidae, Primates) PB - Istituto Italiano di Antropologia VL - 82 SP - 47 KW - airorhynchy KW - alouatta KW - analysis KW - craniology KW - distance KW - euclidean KW - functional KW - geometric KW - matrix KW - morphometrics KW - pongo AU - Bruner, Emiliano AU - Mantini, Simone AU - Manzi, Giorgio PY - 2004/08// UR - http://www.isita-org.com/jass/Contents/2004%20vol82/Bruner_47_66%5b1%5d%5b1%5d.qxd.pdf ER -