Hearts of chelicerates.

A: Heart of Limulus polyphemus (lateral view, μCT). B: Heart of Hottentotta hottentotta (dorsal view, cLSM). C: Ostium and proximal part of cardiac artery of Euscorpius tergestrinus (lateral view, cLSM; red cyan anaglyph, use goggles), arrowhead indicates longitudinal fibers of the epicard. D: Ostium and proximal part of cardiac artery of Lasiodora parahybana (lateral view, cLSM), arrowhead indicates longitudinal fibers of the epicard. aa: anterior aorta; ca: cardiac artery; os: ostium; pa: posterior aorta.