Body shape varies drastically across vertebrates, making it an effective trait to study when trying to understand macroevolutionary patterns of phenotypic variation. Body shape has been quantified in many ectothermic clades, but rarely in mammals. The goal of our research is to quantify body elongation in the family Sciuridae, as this area has been understudied thus far. Squirrels (Sciuridae) can be sorted into three distinct ecotypes based on life history and locomotion: ground, tree, and gliding. This leads to questions regarding differences in body shape between ecotypes in their respective environmental niches, and how differences in elongation correlate to different types of locomotion. We hypothesize that tree squirrels will be the most elongate, followed by ground squirrels, then gliding squirrels due to ecological and functional adaptations. To determine the potential differences in elongation between ecotypes, we will calculate the head-body elongation ratio (hbER) from skeletons held at natural history museums. We will use phylogenetic comparative methods to compare hbER between the three ecotypes. Thus far, our preliminary data shows both gliding and ground squirrels to have a statistically significant difference in hbER from tree squirrels. Tree squirrels are the most elongate, followed by ground, then gliding squirrels. We hope to further test differences between the hbER of ground and gliding squirrels with an increased sample size. Research on correlations between robustness and bone density in this clade is already underway, which will complement our results on elongation ratios between ecotypes.