@article{dickinson_boettcher_smith_worden_swindell_seelye_pastor_hartstone-rose_2021, title={Myological variation in the forearm anatomy of Callitrichidae and Lemuridae}, volume={5}, ISSN={["1469-7580"]}, url={https://doi.org/10.1111/joa.13440}, DOI={10.1111/joa.13440}, abstractNote={Abstract The anatomy of the primate forearm is frequently investigated in terms of locomotor mode, substrate use, and manual dexterity. Such studies typically rely upon broad, interspecific samples for which one or two representative taxa are used to characterize the anatomy of their genus or family. To interpret variation between distantly related taxa, however, it is necessary to contextualize these differences by quantifying variation at lower hierarchical levels, that is, more fine‐grained representation within specific genera or families. In this study, we present a focused evaluation of the variation in muscle organization, integration, and architecture within two speciose primate families: the Callitrichidae and Lemuridae. We demonstrate that, within each lineage, several muscle functional groups exhibit substantial variation in muscle organization. Most notably, the digital extensors appear highly variable (particularly among callitrichids), with many unique configurations represented. In terms of architectural variables, both families are more conservative, with the exception of the genus Callimico —for which an increase is observed in forearm muscle mass and strength. We suggest this reflects the increased use of vertical climbing and trunk‐to‐trunk leaping within this genus relative to the more typically fine‐branch substrate use of the other callitrichids. Overall, these data emphasize the underappreciated variation in forearm myology and suggest that overly generalized typification of a taxon's anatomy may conceal significant intraspecific and intrageneric variation therein. Thus, considerations of adaptation within the forearm musculature should endeavor to consider the full range of anatomical variation when making comparisons between multiple taxa within an evolutionary context.}, journal={JOURNAL OF ANATOMY}, publisher={Wiley}, author={Dickinson, Edwin and Boettcher, Marissa L. and Smith, Madison R. and Worden, Nikole A. and Swindell, Sidney R. and Seelye, Jason S. and Pastor, Francisco and Hartstone-Rose, Adam}, year={2021}, month={May} }
 @article{hartstone-rose_boettcher_seelye_worden_dickinson_2020, title={Intraspecific and intrafamilial variation in primate forearm muscle architecture}, volume={34}, ISSN={["1530-6860"]}, DOI={10.1096/fasebj.2020.34.s1.05802}, abstractNote={Recent studies have examined locomotion and postural correlates of primate forearm muscle architecture. However, these have done so using relatively small sample sizes – usually one or two specimens per species, and relatively few species per genus and family. Thus, little is known about intraspecific variation in forearm muscle fiber architecture in primates, and whether there are notable differences in these variables between closely related taxa. The current study addresses these deficits by assessing both qualitative (presence/absence of specific muscles) and quantitative (physiological cross-sectional area [PCSA], fascicle length [FL] and muscle mass [MM]) differences in forearm muscle architecture of larger intraspecific and samples with greater coverage of specific primate families than had been included in previous work. Namely, we studied 30 callitrichid specimens from 11 species, 15 lemurid specimens from 7 species and 9 cebids from two species - a total sample size of 54 specimens from 20 species. Within species, FL varied the greatest among architectural variables and MM varied the least. We also found that there is great variation in both the extent of separation and fusion of flexor digitorum superficialis and profundus, and in the extent of accessory extensors in most species of callitrichids and Saimiri, but no variation in the gross forearm muscle architecture within lemurids. More than a quarter of the callitrichid specimens had forearm muscle configurations that deviate from their standard published description, suggesting that blanket characterizations of anatomical configurations at the genus or family level may obscure potentially important intra- and inter-specific trends. Support or Funding Information National Science Foundation: IOS-15-57125, BCS-14-40599}, journal={FASEB JOURNAL}, author={Hartstone-Rose, Adam and Boettcher, Marissa and Seelye, Jason and Worden, Nikole and Dickinson, Edwin}, year={2020}, month={Apr} }