The Myodocopida is one of the two orders within the Myodocopa, in turn a subclass of the Ostracoda. The Myodocopida are distinguished by a worm-like seventh limb, and, usually, a rostrum above an incisure (notch) from which the antennae can protrude. Unlike other ostracods, many species of the Myodocopida have lateral compound eyes Research on the cypridinid species Macrocypridina castanea have shown that the âÂÂwindowâ above its eyesâÂÂa transparent area on the shellâÂÂcontains a nanostructure that transmits an unusually high 99% of blue light (350âÂÂ630 nm)âÂÂthe predominant light in its environmentâÂÂallowing it to efficiently reach the eyes. Over the last thirty years there has been much research into the morphology, behaviour and distribution of myodocopids. More recently, DNA sequences have been used to investigate the phylogeny of various groups.