Fossilized Cybister explanatus
Cybister explanatus is a neararctic[1] species of diving beetle belonging to the Cybister genus and the Dytiscidae family. North American Species, (including C. explanatus) are placed in the sub genus Nealocomerus.[1]
Morphology[]
The beetles have an overall smooth dorsal surface coloured in hues of olive or moss green with a lustrous texture to it. The body is an overall almond shaped with a very minuscule scutellum almost Entirely concealed by the pronotum. The elytra have conspicuous creamish-white coloured bands present on the lateral margins. The antennae are thin and filamentous. The ventral surface is a lustrous reddish-bronze colour with a distinctly aureate appearance. The hind legs are elongate and densely smothered with hydrophobic setae which allows underwater manoeuvrability. The mandibles are powerful and sickle-shaped and are bracketed by the maxillary palps and sheathed by the labrum.
Ecology[]
adults of C. Explanatus are commonly consumed as food by indigenous tribes and are considered edible,[2] Even in the present times, the beetles are roasted and eaten as a Taco filling.[3] As with all the other species of Dytiscid beetles, C. Explanatus is amphibious in nature (being predominantly aquatic during it’s larval stage) adults hunt by chasing small creatures that happen to occur within the beetles vicinity, using their powerful legs to thrust themselves and dart across the water in a manner similar to a torpedo, the beetle relentlessly pursues the prey before using its robust jaws to deliver a fatal blunt blow to the prey which usually occur in the form of other aquatic insects such as mosquito larvae and water fleas occasionally minnows.