HYPSIBIIDAE Pilato, 1969

Eutardigrades without cephalic papillae. A paired elliptical organ may be (rarely) present on the head (Fig. 6). The two diploclaws of each leg, usually different in the shape and size, are asymmetrically arranged with respect to the median plane of the leg (conventionally described as: 2121). Each diploclaw has a basal section which is continuous with the secondary branch, and a primary branch that is joined through a relatively flexible connection (Fig. 1 E). Only exceptionally the main branch appears rigidly joined to the secondary branch or quite separated from it. Many types of bucco-pharyngeal apparatuses can be distinguished; when peribuccal structures are present, the sagittal plane passes between those structures.

Types of claws. Many types of claws can be recognized within the family.

The Isohypsibius type (Fig. 10 A)

The secondary branch and the basal section form an almost right angle. Diploclaws of the same leg are slightly different in the size and shape from each another.

The Ramazzottius (= oberhaeuseri) type (Fig. 10 C)

Diploclaws of the same leg extremely different from one another in the size and shape. External claws with basal section longer than the secondary branch; primary branch very long and slender; internal claws short and stout.