Internal conulariid structures unveiled using µCT

Abstract An extensive sample of well-preserved conulariids from the Pennsylvanian North American Midcontinent (Texas and Oklahoma, USA) have been studied using X-ray micro-Computed Tomography (µCT) shown structures identified as longitudinal muscle bundles a potential gastric cavity. These unequivocal appear in several specimens coming different sites. Their preservation varies cavity with some individuals to only others. The fuse apically or medially, normally forming V-shaped pairs, they extend along theca/exoskeleton, parallel corner, towards aperture. Longitudinal predominant perradial positions. Although there articles on conulariid soft parts, most them refer relic parts. This is first time that these are µCT. Discovery parts contributes knowledge metazoan evolutionary history.