Dermal papillae are small protrusions on the cuticle of onychophorans, a group of animals commonly known as velvet worms. These structures give the group their common name, as they have a velvet-like feel when touched. Dermal papillae come multiple forms and cover the body of onychophorans in rings known as annulations.
Talk about structure and make a diagram showing differences between Peripatidae and Peripatopsidae primary papillae
Type 1 sensilla are a specialized variant of primary papilla with a prominent apical piece covered in scales and a sensory bristle with a textured base. These papillae act as mechanoreceptors, giving the animals a sense of touch, and occur in peripatid velvet worms.
Type 1 sensilla are similar to type 1 sensilla but lack an apical piece and have a far longer bristle.
Spindle-shaped sensilla are a modified version of Type 1 sensilla that have a large, spindle-shaped apical piece and a short, thorn-like bristle. Like regular type 1 sensilla, these also only occur in peripatid velvet worms. In life, spindle-shaped sensilla make up an array known as the antennal sensory field. This is located on the underside of the antennae on its proximal (closer to the base) portion.
Crater shaped papillae