Family Armadillidae

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A very common and diverse group usually found in native New Zealand environments. Currently, 26 species are described from New Zealand (Green, 1971; Vandel, 1977). Species-level identification is difficult, genus-level taxonomy is unresolved, and many species remain undescribed.

The flagellum of antenna has two articles (segments). The head is compressed longitudinally (front to back) and bears a wide frontal shield; in some taxa there is a groove on the upper margin of the frontal shield, creating appearance of a transverse ridge.

With few exceptions, Armadillidae are able to roll into a ball. In some taxa (e.g., Spherillo/Sphaerilloides) the posterior corners of the first pereonite have a V-shaped notch into which the epimera of the second pereonite fit when the animal rolls up.

The telson is wide, with quadrangular distal part. The basal segment of uropods (protopod) is large and flattened, with a concave medial margin, and fits in the gap between the telson and the epimera of the fifth pleonite. In most species the exopod is reduced, inserted dorsally near the medial margin of the protopod, and does not reach the tip of the protopod. In Pseudodiploexochus the exopod is absent and only the protopod is visible.

The body length in different species ranges from about 2 mm to 20 mm. The eyes are usually moderate in size, rounded, and each eye is composed of 10-25 ocelli (number of ocelli is reduced in very small species - e.g., 4 ocelli per eye in Cubaris minimus, 2 in Pseudodiploexochus). Dorsal ornamentation can be absent (dorsum smooth), or present in the form of various tubercles, ridges, lobes, and spines. Colours variable. Five pairs of pleopodal lungs are usually present (not visible in preserved specimens); lungs absent in Pseudodiploexochus.