Ideocaira hook

Male coxa I hook

In some araneids, the male coxa I has a well-developed ectal projection (character 18), which is functionally linked to a groove in the prolateral surface of the femur II ( Scharff & Coddington, 1997). In the present study, the ancestral state optimizes unambiguously as absence of the coxa I projection, with three independent origins, three subsequent losses and one regain. This evolutionary hypothesis is similar to the results obtained by Scharff & Coddington (1997) and suggests the need for behavioural and ultrastructural data to delimit this character properly.