Dr. Murai Éva szerk.: Parasitologia Hungarica 21. (Budapest, 1988)
DISCUSSION The species studied belong to different morphological and, very likely, to different phyletic groups. The morphological similarity among them as well as among all the members of the genus Anoplocephaloides consists of the pattern of uterus development. RAUSCH (1976) considered this feature as a principal criterion for distinguishing the genera Paranoplocephala and Anoplocephaloides. The same author drew attention to the heterogeneity of the composition of Anoplocephaloides and contemplated about the origin and phylogeny of the different species and groups of species. During- the last years some new species have been described (KAMIYA et al., 1979; MURAI et al., 1980; TENORA et al., 1981-1982; GENOV et al., 1984) and new information about the known species have been accumulated (TENORA and MURAI, 1980; TENORA et al., 1981-1982; TENORA and STANEK, 1985; TENORA et al., 1985; GENOV, 1984). On the basis of the new morphological data and the knowledge of the distribution of the cestodes' and their hosts, a new grouping of the species could be proposed which corresponds more fully to probable pattern of their phylogeny. Our proposal for such grouping is presented in Table 5. The species of the group "romeroiagi " possess short strobilae consisting of a small number of proglottides, a trichoid cover on the tegument and a vagina opened posteriorly to the male pore. The similarity among these species was emphasized by TENORA and STANEK (1985). These authors explained the unusual geographical distribution of the group, supposing that A. pseudowimerosa Tenora, Murai, Valero et Outillas , 1981-1982 (from Ory(^olagj^_cuniculus in Spain) had been introduced in Europe from the Neotropic region. We consider that the range of this group could be explained only on the basis of the data on the origin and colonization of their hosts (THENIUS, 1972) belonging to the fam. Leporidae. Most probably, these cestodes appeared in the Pliocene when all the recent genera of Leporidae had been formed. The first possibility for the formation of the group " romeroiagi " is the early Pliocene when Romor_olagus and its related genera appeared. The other possibility is connected with the last divergence of Leporinae in the late Pliocene when the Palaearctic genus _Pjfy_çtolagus_, the Nearctic Sylvilagus (hosts of Anoplocephaloides spp.) and the cosmopolitan genus Lepus arose. The genus Sylvilagus colonized the Neotropic region during the late Pleistocene and this fact can explain the record of the group "romeroiagi" there. The recent distribution of the group seems relict (RAUSCH, 1976 considered that " A. floresbarroetae must represent a relatively recent parasite-host adaptation") and can be regarded as a survival of a widespread fauna during the Pliocene and Pleistocene. Presumably, the Quaternary changes of the climate in the Northern hemisphere exerted influence on the restriction of the area of distribution of these cestodes. New data elucidating the evolution of this group can be obtained as a result of the investigations on the cestode fauna of Leporidae which has insufficiently been studied. The fourth species of the genus Anoplocephaloides parasitizing lagomorphs, A. wimerosa (Montez, 1880) from Leporidae in Western Europe, is conditionally placed in an independent group. We presume its probable similarity with the species of the group " romeroiagi " but the information about its morphology is very scarce. There are no data about the presence of trichoid cover on the tegument of this species (BAER, 1927; JOYEUX and BAER, 1936; SPASSKY, 1951). The phylogenetic detachment of the group " transversaria" was substantiated by RAUSCH (1976). These cestodes, characterized by long ribbon-like strobila, occur only in rodents of the tribe Marmotini. One of the species, A. wigginsi (Rausch, 1954), has a Holarctic distribution and has been recorded in two relict localities in Alaska and Cukotka (RAUSCH, 1976). The disunited range of A. wigginsi testifies to its widespread distribution in Beringia during the late Pleistocene* It should be supposed that the other two species of this grout; (A. transversaria (Krabbe, 1879) and A , ryjikovi (Spassky, 1950)) descended from a forn related to A. wigginsi after the appearance of their hosts (Marmota spp. ) in Eurasia during the early Pleistocene, since cestodes with similar characteristics were not found in Nearctic Marmota spp. (RAUSCH, 1976). The species of the group " acanthocirrosa" are characterized by a relatively long strobila
