Ophiuroidea is one of the most diverse classes among extant echinoderms. They occupy marine habitats, ranging from the poles to the equator, from intertidal reefs to hadal depths of at least 6,500 m. The brittle star’s arm includes a series of vertebral ossicles, each articulating with other proximally and distally. This articulated internal skeleton gives the ophiuroid arm a range of motion, important for locomotory and feeding behaviors. This study involves a quantitative investigation of the 3D shape of vertebral ossicles using Micro CT scanned images and geometric morphometric analyses. We aimed to find out how the morphology of the vertebrae changes among species, but also across different habitats. In this study, six vertebrae were selected from the middle and distal part of six different species (in total 36 vertebrae), belonging to the intertidal and subtidal zone with epizoic and non-epizoic behaviors. The result of a PerMANOVA shows that there is a significant difference in ossicle morphology among species and also various habitats. Further analysis including PCA depicted that some landmarks on dorso-proximal and dorsoventral vertebrae reflect possible ecological adaptations. Accordingly, the specimens showed habitat related differences, independent of their phylogenetic relationship

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