A NEW SPECIES OF PROLEPTONCHUS LORDELLO, 1955 (NEMATODA, LEPTONCHIDAE) FROM SPAIN, WITH A CLADISTIC STUDY OF THE GENUS

Proleptonchus fagi sp. n. is described with specimens from Spain. It i s characterized by a large size (1.63-2.25 mm), slender body (a = 36-5 3), lip region, slightly offset, low and with an incipient disc-like p erioral area, odontostyle 8-9.5 mum long, pharyngeal bulb 19-24% of ph arynx length, posterior female genital branch with reduced oviduct sep arated from uterine sac by sphincter, tail relatively long (18-30 mum) , spicules long (41-50 mum) and 3-6 ventromedian supplements. Cladisti c analysis based primarily on qualitative characters was carried out w ith sixteen known species of Proleptonchus Lordello, 1955. The analysi s showed a close phylogenetic affinity between P. weischeri Goseco & F erris, 1976 and P. fagi sp. n., the two known European species. The hy pothesis of a primary radiation of Proleptonchus species into the Gond wana supercontinent is in concordance with this cladistic study.