Colinatydidae Family

Family Colinatydidae

This is a recently raised family (2015) coming out of molecular studies of cephalaspideans. (A new phylogeny of the Cephalaspidea based on expanded taxon sampling and gene markers. Oskars, Bouchet & Malaquias, 2015.)
The Colinatydidae contains a single genus, the Colinatys.
They possess an external shell that is unique among the cephalaspideans in being covered by a distinctive reticulated pattern of incised white squares but is otherwise translucent such that internal organs may be visible within. The shape of the shell is quadrangular (blunt apex), wider anteriorly and slightly convex sides. The aperture has a sharp outer lip and extends past the spire which is depressed.
The shells are small, up to 2 mm in the adult. The animal is translucent white to dirty cream in colour retiring in nature, usually only extending externally as far as the prominent eye spots and can be accommodated entirely within the shell. An operculum is absent.
The headshield is bilobed anteriorly with the head tentacles short, rounded and widely spaced.
The foot is shorter than the shell. Eye spots are prominent. The gill is not visible externally.