Pallenopsidae Fry, 1978

Bamber, Roger N., 2004, Pycnogonids (Arthropoda: Pycnogonida) from French Cruises to Melanesia, Zootaxa 551, pp. 1-27 : 14

Pallenopsidae Fry, 1978

There has been an erratic history of the familial attribution of species of the genus Pallenopsis Wilson, 1881 . For many years it was placed within the Callipallenidae , with which it was consistent in having, inter alia, a 10­articled oviger in both sexes, palps absent or present only as small, one­articled buds, and functional chelae.

Stock (1978) transferred the genus to the Phoxichilidiidae , and Arnaud and Bamber (1987) followed his example. Child (1992; 1995) returned the genus to the Callipallenidae , an opinion supported by Bamber (2002a) as the protonymphon larva was not consistent with those of the Phoxichilidiidae .

All of these opinions were attempting to fit the genus into one of the existing families of the Pycnogonida, despite the fact that at least two of those were generally accepted as being polyphyletic (e.g. Arnaud & Bamber, 1987).

In his multivariate analyses, Fry (1978) found Pallenopsis to be isolated near (but not very close to) Anoplodactylus and Prototrygaeus . He therefore proposed the family Pallenopsidae , within the suborder Pallenopsida. Although Fry maintained that the results of this analysis were only a "primary hypothesis of degrees of overall morphological similarities", when judged against the continuing controversy over the placement of this genus in relation to the Callipallenidae and the Phoxichilidiidae they reinforce the concept of the distinction of this genus at the family level.

Recent cladistic analyses of the Pycnogonida ( Arango 2002; 2003) indicated that the genus Pallenopsis related poorly to either the Phoxichilidiidae or the Callipallenidae .

It now seems appropriate to take the logical conclusion from these various clues, and recognize the genus as inappropriate to either of these families; rather, the family Pallenopsidae of Fry (1978) is re­erected for Pallenopsis . It may further prove appropriate (or at least convenient) to raise Stock’s (1974) subgenera to full generic rank.