An interspecific analysis of relative jaw-joint height in primates.

Title

An interspecific analysis of relative jaw-joint height in primates.

Creator

Armfield Brooke A; Vinyard Christopher J

Publisher

American journal of physical anthropology

Date

2010
2010-08

Description

Jaw-joint height (JJH) above the occlusal plane is thought to be influenced by cranial base angle (CBA) and facial angulation during growth. To better understand how JJH relates to midline craniofacial form, we test the hypothesis that relative increases in JJH are correlated with increasing CBA flexion and facial kyphosis (i.e., ventral bending) across primates. We compared JJH above the occlusal plane to CBA and the angle of facial kyphosis (AFK) across adults from 82 species. JJH scales with positive allometry relative to a skull geometric mean in anthropoids and most likely strepsirrhines. Anthropoid regressions for JJH are elevated above strepsirrhines, whereas catarrhines exhibit a higher slope than platyrrhines. Semipartial correlations between relative JJH and both CBA and AFK show no association across a small strepsirrhine sample, limited associations among catarrhines and anthropoids, but strong correlations in platyrrhines. Contrary to our hypothesis, however, increases in relative JJH are correlated with relatively less flexed basicrania and more airorhynch faces (i.e., reduced ventral bending) in platyrrhines. The mosaic pattern of relationships involving JJH across primate clades points to multiple influences on JJH across primates. In clades showing little association with basicranial and facial angles, such as strepsirrhines, the potential morphological independence of JJH may facilitate a relative freedom for evolutionary changes related to masticatory function. Finally, failure to associate relative JJH and basicranial flexion in most clades suggests that the relatively taller JJH and more flexed basicrania of anthropoids compared to strepsirrhines may have evolved as an isolated event during the origin of anthropoids.

Subject

Analysis of Variance; Animals; Female; Haplorhini/*anatomy & histology; Male; Phylogeny; Posture/*physiology; Regression Analysis; Skull/anatomy & histology; Strepsirhini/*anatomy & histology; Temporomandibular Joint/*anatomy & histology

Identifier

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

519–530

Issue

4

Volume

142

Citation

Armfield Brooke A; Vinyard Christopher J, “An interspecific analysis of relative jaw-joint height in primates.,” NEOMED Bibliography Database, accessed March 28, 2024, https://neomed.omeka.net/items/show/2949.