Filetički odnosi unutar sekcije SynochetaLegrand, 1946 (Crustacea, Isopoda, Oniscidea)Balkanskog poluostrva

Abstract

Aktuelna sistematika sekcije Synocheta na gotovo svim nivoima ne odražava realne filetičke veze. Neobična distribucija, nejasni diferencijalni karakteri familije Styloniscidae i njene veze sa familijom Trichoniscidae su problematični. Kriterijumi podele Trichoniscidae na podfamilije su nejasni, nedosledni i često neprimenljivi. Otuda ne čudi krajnje uprošćena podela koja ne oslikava realne filetičke odnose unutar grupe, koji su znatno kompleksniji. Od 593 vrste Synocheta, trećina (većinom endemita), naseljava Balkan, što nameće ovo područje kao jedan od centara diverzifikacije i diverziteta grupe, i čini ga idealnim za sagledavanje realnih filetičkih odnosa. Ovo je definisalo glavne ciljeve naše studije: što potpunije sagledavanje faune balkanskih Synocheta kroz taksonomsku obradu; utvrđivanje filetičkih veza na osnovu kompleksa relevantnih karaktera uporednim analizama, sa težištem na konzervativnijim karakterima, što do sada nije učinjeno. Konstatovali smo u balkanskoj fauni iz familije Styloniscidae 4 roda sa 15 vrsta, od toga 3 roda i 4 vrste su nove za nauku; iz familije Trichoniscidae 33 roda sa 176 vrsta, od toga 1 novi rod i 18 novih vrsta. Od tog broja 27 rodova i 161 vrsta Synocheta je endemično za Balkan. Kod Styloniscidae smo utvrdili znatno veći diverzitet i heterogenost od onoga što je bilo do sada poznato, što ukazuje na moguće poreklo ove grupe sa prostora severne Gondvane (delom inkorporirane u prostore Balkana), zajedničko sa familijom Trichoniscidae. Rekonstruisali smo najznačajnije momente u filogeniji Trichoniscidae: vrlo rano razviće konglobacije, uz masivan integument i razvijenu ornamentiku kao adaptacije; prelazak na zaštitu stereotaksacijom; evolucija ka aktivnijoj zaštiti i gubitku „oklopa” što dovodi do velike adaptivne radijacije. Pri tome smo pokazali da su karakteri koji su smatrani izvedenim osobinama zapravo pleziomorfni. Predstavili smo osnovne evolutivne tokove u familiji Trichoniscidae, kao i filetičke veze koje proizilaze iz ove studije: Haplophthalminae su stara grupa koja poseduje niz pleziomorfnih karaktera; Buddelndiellinae su stara grupa sa znatno bližim filetičkim vezama sa Haplophthalminae; Thaumatoniscellinae imaju vrlo davno zajedničko poreklo sa Haplophthalminae; Trichoniscinae su mlađa, parafiletička grupa, a mnoge linije su nezavisno evoluirale od podfamilije Haplophthalminae. Ovom studijom smo u nekim segmentima dokazali dijametralno suprotne, znatno kompleksnije filetičke veze unutar Synocheta u odnosu na do sada prezentovane.

Current systematic Synocheta section at almost all levels fails to reflect the real phyletic relations. Unusual distribution and vague differential characters of Styloniscidae family and its relationships with the Trichoniscidae family are problematic. The division criteria for forming Trichoniscidae subfamilies are unclear, inconsistent and often unenforceable. Hence, the extremely simplified division that does not reflect the real phyletic relations within the group, which are much more complex, is not surprising. Of 593 Synocheta species, one third (mostly endemic) inhabit the Balkans, which imposes this area as one of the centers of diversification and diversity of the group, and makes it ideal for the analysis of real phyletic relations. This defined the main goals of our study: as complete assessment of the fauna of the Balkan Synocheta as achievable through taxonomic treatment; determining phyletic relations through comparative analyses based on the complex of relevant characters, with the emphasis on the more conservative ones, which has not been accomplished thus far. In the Balkan fauna of the Styloniscidae family, 4 genera with 15 species were identified, of which 3 genera and 4 species are new to science; similarly, the 33 genera with 176 species from the family Trichoniscidae found in Balkan fauna included one new genus and 18 new species. Of that number, 27 genera and 161 Synocheta species are endemic to the Balkans. In Styloniscidae, we found much greater diversity and heterogeneity than was previously established, which indicates that these groups possibly originate from the northern Gondwana (partly incorporated into the Balkans area), in common with Trichoniscidae family. We reconstructed the most important moments in the Trichoniscidae philogeny: early development of conglobation, with massive integument and developed rnamentation as adaptations; transition into protection via stereotaxation; evolution toward more active protection and loss of "armor", which leads to extensive adaptive radiation. In addition, we have shown that the characters that were previously considered derived properties are actually plesiomorphic. We have presented the basic evolutionary trends in Trichoniscidae family, as well as phyletic relations arising from this study: Haplophthalminae are the ancient group ossessing a wide range of plesiomorphic characters; Buddelndiellinae are the ancient group with a much VI closer phyletic relations to Haplophthalminae; Thaumatoniscellinae share a common, and very distant, origin with Haplophthalminae; Trichoniscinae are a younger paraphyletic group and many lines have evolved independently of the Haplophthalminae subfamily. In this study, in some segments, we have demonstrated substantially more complex phyletic relations within Synocheta, diametrically opposed to the previously presented findings.