ON THE EVOLUTION AND THE CLASSIFICATION OF SPIDERS, THE MESOZOIC SPIDER FAUNAS, AND DESCRIPTIONS OF NEW CRETACEOUS TAXA MAINLY IN AMBER FROM MYANMAR (BURMA) (ARACHNIDA: ARANEAE).

The Mesozoic spider (Araneae) faunas - mainly preserved in ambers - are listed and discussed, their evolution, fauna and biogeography are dealt with. Observations on the behaviour and the biology of Mesozoic spiders are treated, e. g. parts of capture webs, prey, an egg sac, camouflage, the first case of a mating plug and genital selfmutilation of a male in 100 million year-old Burmese amber. - The mesozoic spider fauna of mainly higher strata (preserved in amber, besides relatively few taxa in stone) has turned out to be strongly dominated by haplogyne taxa besides members of the entelegyne Deinopoidea: Uloboridae. Taxa of the ecribellate Araneoidea are extremely rare, few reports of the families Nephilidae, Zygiellidae and probably Theridiidae exist. Sure Mesozoic reports of members of the today most diverse Linyphiidae and of the RTA-clade like Salticidae or Lycosidae are missing (!). So apparently most families of spiders radiated - or even originated - only DURING A SIXTH of the 400 million years of spider evolution. - Diversity of the faunas and extinctions: See the list of the families and the annotated list. - The results of my (preliminary) studies of the Mesozoic (mainly Cretaceous) spider faunas are as follows: - Up to 39 families are reported, the determination of 7 or 8 of these is unsure, only 9 (less than a third of the surely reported 30 families) are entelegyne. - Almost all of these families are reported from the Cretaceous; the Juraraneidae are only known from the Jurassic, the Mongolarachnidae from the Jurassic to the Cretaceous, Spatiatoridae from the Cretaceous to the Eocene (Baltic amber). Mesothelae - probably the only spiders of the Palaeozoicum and surviving up to now - are reported first from Mid Cretaceous Burmese amber (Burmite). - 12 (more than one third) of the surely reported families are extinct; only one of these, the Spatiatoridae, survived up to the Eocene. Besides the mygalomorph Fossilcalcaridae all the extinct families are members of the Haplogynae. - Ca. 110 genera are reported: 1 of the Mesothelae, 11 of the Mygalomorpha, ca. 100 of the Araneomorpha: Up to 78 of the Haplogynae (incl. the Archaeoidea) and and ca. 25 of the Entelegynae (= 1/4 of the Araneomorpha). - Most genera are only known from the Cretaceous; 5 from the Triassic: Ambiortiphagus (?Atypidae), Argyrarachne (Araneomorpha indet.), Mesaranea (Araneoidea indet.), Rosamygale (?Hexathelidae) and Triasaraneus (Araneomorpha indet.); 5 from the Jurassic: Eoplectreurys (Plectreuridae), Juraraneus (Juraraneidae), Jurarchaea (Archaeidae), Sinaranea (fam.?) and Tatbragaraneus (Uloboridae): The only genus of the Entelegynae. - Members of only very few genera - all are members of the Haplogynae - survived up to now, probably Orchestina (Oonopidae), Leclercera (Psilodercidae) and Scytodes (Scytodidae). - CIBELLATE genera: (a) Araneomorpha: ca. 25 % in the Cretaceous but only ca. 10 % in the Eocene Baltic amber forest; (b) Araneoidea: > 50 % in the Cretaceous but only ca. 7 % in the Eocene (in which ecribellate members of the RTA-clade dominate). A strong removal of cribellate genera exist during more than 100 million of years. - Ca. 140 Mesozoic SPIDER SPECIES are known. No Mesozoic species survived up to now or is known to survive up to the Eocene (e.g. to the Baltic amber forest). Erroneous, dubious and incorrect determinations and conclusions are discussed; reports of several spider (sub)families like Araneidae, Deinopidae, Linyphiidae, Mecysmaucheniinae (sub Mecysmaucheniidae) and Tetragnathidae have to be deleted from the list of Mesozoic spiders. - Considerable results of this study regard the phylogeny and evolution of spiders. Some ideas on the - mainly palaeozoic and mesozoic - early evolution of spiders including a chronocladogram, the classification of spiders and hypothetic extinct taxa as well as a list of the main innovations in the long evolution of spiders are treated. A TWICE ORIGIN OF THE CRIBELLUM is accepted. The possibele existence of two „BIG BANGS OF SPIDER RADIATION” is discussed which probably happened (1) just after the mass extinction events during the Triassic: the „Triassic explosion of the Cribellates” (Haplogynae and Entelegynae part (a): Oecobioidea and Araneoidea including the deinopoid branch), and (2) the „Plaeocene explosion” (after the KT-events) of members of the Entelegynae part (b), the RTA-clade. The origin and diversification of orb-weaving Araneoidea is found much older than the origin of the not orb-weaving families like Linyphiidae and Theridiidae. This find indicate that the araneoid kinds of irregular capture webs derived from the orb web but not the reverse. Results of moleculargenetic studies are not compatible with proofs of fossil taxa. - Taxonomy: Transfers: The Cretaceous taxon Archaemecys arcantiensis SAUPE & SELDEN 2009 (from France) is transfered from the family Mecysmaucheniidae to the Archaeidae: Archaeinae (n. relat.). The genus Filiauchenius WUNDERLICH 2008 - including its type species paucidentatus - may be a member of Lacunauchenius WUNDERLICH 2008 (quest. n. syn. and n. comb.). The genus Hypertheridiosoma WUNDERLICH 2012 is transferred from the Theridiosomatidae to the Praeterleptonetidae (n. relat.) which may be polyphyletic. - Certain family diagnoses (e. g. of the Oecobiidae, Spatiatoridae, Theridiosomatidae and Uloboridae) have strongly to be modified if the extinct (Mesozoic) taxa are included. - A new spider classification is proposed (p. 46): The extinct taxon (order) Uraraneida SELDEN et al. 1991 is regarded as a suborder of the order Araneae (n. stat.), based mainly on the existence of an opisthosomal spinning apparatus, and as sister taxon of the suborder called Araneida. Araneomorpha SMITH 1902 is regarded as sister taxon to the Mygalomorpha. As Microorders of the suborder Araneomorpha are regarded the „Basal Haplogynae” n. taxon and the Cleistospermiata n. taxon. With some hesitation I regard the branch Hypochilomorpha MARX 1888 in a wide sense, including the nominal superfamilies Austrochiloidea and Hypochiloidea. As related branches are regarded the Entelegynae ROEWER 1961 which is restored, see fig. G, and first the Dipneumonomorphae PETRUNKEVITCH 1933 (= Apneumonomorphae PETRUNKEVITCH 1933 and Araneoclada PLATNICK 1977) (n. syn.). - Described for the first time are furthermore (all in Mid Cretaceous Burmite): A single family: Fossilcalcaridae (Mygalomorpha), 4 subfamilies: Longissipalpinae and Pedipalparaneinae of the Mongolarachnidae, Vetiatorinae of the Spatiatoridae and Retrooecobiinae of the Oecobiidae; 35 genera and 66 species of 17 families: Dipluridae, Eopsilodercidae, Fossilcalcaridae, Hersiliidae, Lagonomegopidae, Mongolarachnidae, Oecobiidae, Pholcochyroceridae, Plumorsolidae, Praeterleptonetidae, Psilodercidae, Salticoididae, Segestriidae, Spatiatoridae, Tetrablemmidae, Theridiidae and Uloboridae. A Cretaceous member - probably Leptonetoidea or Oecobioidea or Pholcoidea - indet. in stone from Liaoning (China) is described but not named. [ABSTRACT FROM AUTHOR]