TY - JOUR
T1 - A comparative analysis of vibrissa count and infraorbital foramen area in primates and other mammals
AU - Muchlinski, Magdalena N.
N1 - Funding Information:
The author would like to thank Adam Gordon and Scott Williams for their assistance the phylogenetic corrections used for this study. A special thank you is extended to Adam Gordon, who was extremely helpful in all stages of preparing this manuscript. Helpful comments on earlier drafts were also provided by Liza Shapiro, Chris Kirk, Nate Dominy, Robert Sussman, and Rebecca Lewis. Access to specimens was granted by: American Museum of Natural History; Smithsonian Institute; University of California, Santa Cruz; and the University of Texas at Austin. This project was funded by a National Science Foundation DIG: 0622422 ; a Field Museum of Natural History visiting scholarship; a Philanthropic Educational Opportunity Fellowship; and MU-ADVANCE.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2010/6
Y1 - 2010/6
N2 - Vibrissae are specialized sensory "hairs" that respond to mechanical stimuli. Sensory information from vibrissae is transmitted to the brain via the infraorbital nerve, which passes through the infraorbital foramen (IOF). Several analyses have documented that primates have smaller IOFs than non-primate mammals, and that haplorhines have smaller IOFs than strepsirrhines. These grade shifts in IOF area were attributed to differences in " vibrissa development." Following earlier analyses, IOF area has been used to derive a general estimate of " whiskeredness" in extinct primates, and consequently, IOF area has been used in phylogenetic and paleoecological interpretations. Yet, the relationship between IOF area and vibrissa count has not been tested, and little is known about how IOF area and vibrissa counts vary among mammals. This study explores how relative IOF area and vibrissa count differ among 25 mammalian orders, and tests for a correlation between IOF area and vibrissa count. Results indicate that primates and dermopterans (Primatomorpha) have smaller IOFs than most non-primate mammals, but they do not have fewer vibrissae. In addition, strepsirrhines and haplorhines do not differ from one another in relative IOF area or vibrissa counts. Despite different patterns documented for IOF area and vibrissa count variation across mammals, results from this study do confirm that vibrissa count and IOF area are significantly and positively correlated (p < 0.0001). However, there is considerable scatter in the data, suggesting that vibrissa counts cannot be predicted from IOF area. There are three implications of these finding. First, IOF area reflects all mechanoreceptors in the maxillary region, not just vibrissae. Second, IOF area may be an informative feature in interpretations of the fossil record. Third, paleoecological interpretations based on vibrissae are not recommended.
AB - Vibrissae are specialized sensory "hairs" that respond to mechanical stimuli. Sensory information from vibrissae is transmitted to the brain via the infraorbital nerve, which passes through the infraorbital foramen (IOF). Several analyses have documented that primates have smaller IOFs than non-primate mammals, and that haplorhines have smaller IOFs than strepsirrhines. These grade shifts in IOF area were attributed to differences in " vibrissa development." Following earlier analyses, IOF area has been used to derive a general estimate of " whiskeredness" in extinct primates, and consequently, IOF area has been used in phylogenetic and paleoecological interpretations. Yet, the relationship between IOF area and vibrissa count has not been tested, and little is known about how IOF area and vibrissa counts vary among mammals. This study explores how relative IOF area and vibrissa count differ among 25 mammalian orders, and tests for a correlation between IOF area and vibrissa count. Results indicate that primates and dermopterans (Primatomorpha) have smaller IOFs than most non-primate mammals, but they do not have fewer vibrissae. In addition, strepsirrhines and haplorhines do not differ from one another in relative IOF area or vibrissa counts. Despite different patterns documented for IOF area and vibrissa count variation across mammals, results from this study do confirm that vibrissa count and IOF area are significantly and positively correlated (p < 0.0001). However, there is considerable scatter in the data, suggesting that vibrissa counts cannot be predicted from IOF area. There are three implications of these finding. First, IOF area reflects all mechanoreceptors in the maxillary region, not just vibrissae. Second, IOF area may be an informative feature in interpretations of the fossil record. Third, paleoecological interpretations based on vibrissae are not recommended.
KW - Euarchontan phylogeny
KW - Fossil record
KW - Infraorbital foramen area
KW - Infraorbital nerve
KW - Vibrissae
UR - http://www.scopus.com/inward/record.url?scp=77953541128&partnerID=8YFLogxK
U2 - 10.1016/j.jhevol.2010.01.012
DO - 10.1016/j.jhevol.2010.01.012
M3 - Article
C2 - 20434193
AN - SCOPUS:77953541128
SN - 0047-2484
VL - 58
SP - 447
EP - 473
JO - Journal of Human Evolution
JF - Journal of Human Evolution
IS - 6
ER -