A comparative analysis of vibrissa count and infraorbital foramen area in primates and other mammals

Magdalena N. Muchlinski

Research output: Contribution to journalArticle

49 Scopus citations

Abstract

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.

Original languageEnglish
Pages (from-to)447-473
Number of pages27
JournalJournal of Human Evolution
Volume58
Issue number6
DOIs
StatePublished - Jun 2010

Keywords

  • Euarchontan phylogeny
  • Fossil record
  • Infraorbital foramen area
  • Infraorbital nerve
  • Vibrissae

Fingerprint Dive into the research topics of 'A comparative analysis of vibrissa count and infraorbital foramen area in primates and other mammals'. Together they form a unique fingerprint.

  • Cite this