Evolution of locomotion in Anthropoidea: the semicircular canal evidence.
Our understanding of locomotor evolution in anthropoid primates has been limited to those taxa for which good postcranial fossil material and appropriate modern analogues are available. We report the results of an analysis of semicircular canal size variation in 16 fossil anthropoid species dating from the Late Eocene to the Late Miocene, and use these data to reconstruct evolutionary changes in locomotor adaptations in anthropoid primates over the last 35 Ma. Phylogenetically informed regression analyses of semicircular canal size reveal three important aspects of anthropoid locomotor evolution: (i) the earliest anthropoid primates engaged in relatively slow locomotor behaviours, suggesting that this was the basal anthropoid pattern; (ii) platyrrhines from the Miocene of South America were relatively agile compared with earlier anthropoids; and (iii) while the last common ancestor of cercopithecoids and hominoids likely was relatively slow like earlier stem catarrhines, the results suggest that the basal crown catarrhine may have been a relatively agile animal. The latter scenario would indicate that hominoids of the later Miocene secondarily derived their relatively slow locomotor repertoires.
Department of Anthropology and Center for Quantitative Imaging, EMS Energy Institute, Pennsylvania State University, University Park, PA 16802, USA. tmr21@psu.edu
Timothy M
TM
Ryan
Mary T
MT
Silcox
Alan
A
Walker
Xianyun
X
Mao
David R
DR
Begun
Brenda R
BR
Benefit
Philip D
PD
Gingerich
Meike
M
Köhler
László
L
Kordos
Monte L
ML
McCrossin
Salvador
S
Moyà-Solà
William J
WJ
Sanders
Erik R
ER
Seiffert
Elwyn
E
Simons
Iyad S
IS
Zalmout
Fred
F
Spoor
D000818:Animals; D005075:Biological Evolution; D005580:Fossils; D000882:Haplorhini / Q000033:anatomy & histology* / Q000502:physiology*; D016018:Least-Squares Analysis; D008124:Locomotion; D010802:Phylogeny; D012665:Semicircular Canals / Q000033:anatomy & histology*; D013045:Species Specificity