However, the number of trichobothria on that region of the patella is quite variable in the family Euscorpiidae Laurie 1896 (Soleglad & Sissom 2001), and thus the similarity between the two species currently placed in Plesiochactas could be a symplesiomorphy.
He also noted that remnants of the ancestral population from which two species differentiated might also exhibit intermediacy, i.e., an early and explicit recognition of symplesiomorphy (shared ancestral characters).
Unfortunately, evolutionary phenomena such as symplesiomorphy, convergent evolution, and phenotypic plasticity can generate phenotypic and genetic patterns that masquerade as hybridity (Dobzhansky 1941; Barber and Jackson 1957; Heiser 1973).
The other example of a new character indicating the autapomorphical condition of this segment is the lack of the midventral condyle in the Ochteridae in contrast to the presence of this condyle in the remaining families (symplesiomorphy).
Patterns of variation typically involve: (1) union of adjacent proximal carpals/tarsals (r/t, i, u/f); (2) amalgamation of y and the more proximal r or t; (3) union of adjacent distal carpals/tarsals (e.g., dt 4 + 5); (4) fusions between postaxial distal mesopodials and c (e.g., dc 4 + c); (5) additional centralia; (6) additional postaxial distal mesopodials, including po; (7) pr; and (8) atavistic separation of amalgamated elements (a symplesiomorphy for the taxon in question; e.g., separation of u from i in Taricha, or separation of dt 4 and 5 in Triturus).
The ideas of symplesiomorphy, apomorphy, and homoplasy were not features of earlier attempts at a natural system: lists of resemblances were the tool employed, and relationship was judged on the basis on numbers of similarities rather than what character states they represented.
Juncosa (1988: 86) states that the intrastaminal appendages are initiated long after the stamens have developed and are therefore "clearl not staminodes." The common diplostemonous androecium in the family (symplesiomorphy) supports the latter interpretation.