A New Suborder of Thysanura for the Carboniferous Insect Originally
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-- @ Zoological Institute, St.Petersburg, 1996 A new suborder of Thysanura for the Carboniferous insect originally described as larva of Bojophlebia, with comments on characters of the orders Thysanura and Ephemeroptera N.Ju. Kluge Kluge, N.Ju. 1996. Anew suborder of Thysanura for the Carboniferous insect originally described as larva of Bojophlebia, with comments on characters of the orders Thysanura and Ephemeroptera. ZoosysfematicaRossica, 4(1), 1995: 71-75. The fossil wingless insect originally described as lama of Bojophlebia procopi (Ephe- meroptera) belongs not to Ephemeroptera, but to Thysanura. It is named Carbotriplura kukalovae gen. et sp. n. and placed in the suborder Carbotriplurina subordo n. Here the order Thysanura is accepted in the FHrner's sense, since the widely accepted Hennig's division of Amyocerata (- Ectognatha sensu Hennig) into Monocondylia and Dicondylia is not based on actual features. Characters of Ephemeroptera and Thysanura are dis- cussed; the differences between tergaliae and paraterga and between wing buds and paranota are explained. N.Ju. Kluge, Department of Entomology, Biological Faculty, St.Petersburg State Univer- sity, Universitetskaya nab. 7, Sf.Petersburg 199034, Russia Kukalova-Peck (1985) has described 3 speci- preserved insufficiently for discussing its sys- mens of wingless insects from the Carbonifer- tematic position. No photograph of "Litho- ous of Europe and North America, which, in neura" piecko is published (there is only a her opinion, are nymphs of Ephemeroptera. drawing in the same paper, Fig. 17), thus its Two of these specimens are described as two systematic position is also obscure. The specil new species of the genus Lithoneura - L men described as the "nymph" of B. procopi piecko Kukalova-Peck, 1985 and L clayesi should be transferred to the order Thysanura. Kukalova-Peck, 1985; one specimen is at- tributed by her to the species Bojophlebia pro- Superclass HEXAPODA Latreille, 1825 copi Kukalova-Peck, 1985. The genus Litho- neura Carpenter, 1938 belongs to the family Class AMYOCERATA Remington, 1954 Syntonopteridae Handlirsch, 191 1; formerly this genus and this family were described only = Ectognatha: Hennig, 1953 (non Ectognatha Stum- from winged insects, features of their nymphs mer-Traunfels, 1891). being unknown. The monotypic genus Bo- jophlebia Kukalova-Peck, 1985 is placed in a. This taxon is characterized primarily by separate family Bojophlebiidae Kukalova- specific structure of antennae, which have Peck, 1985; the holotype of B. procopi is a muscles only in the first segment (scapus). winged insect, and the insect which is con- Since the fossilsare not adequate for recogniz- sidered to be its nymph is the only paratype of ing this character, other diagnostic characters, this species. No arguments are given to prove not so reliable, should be used. One of them is the association of these three "nymphs" with the presence, apart of paired cerci, of an un- the taxa known as winged insects, Litho- paired long paracercus, which has the same neuriidae and Bojophlebiidae respectively. secondary segmentation as cerci; such paracer- The specimen of "Lithoneura" clayesi, a cus is preserved only in Thysanura and numer- photograph of which is published (Kukalova- ous Ephemeroptera and reduced in other amy- Peck, 1985: Figs 19-21), has the structures ocerates. In all known representatives of the 72 N.Ju. Kluge: A new suborder of Thysanura ZQOSYST. ROSSICA Vd. 4 sister group of Amyocerata - the class Entog- on mandibles of various Pterygota, Collem- natha Stummer-Traunfels, 1891 - the paracer- bola, Symphyla, Chilopoda, Crustacea; hence cus is absent. Probably the presence of a pzra- such structure of mandibular condyles is plesio- cercus in Amyocerata is only a plesiomorphy, morphic, being initially present in Mandibu- but since other features are inaccessible, it may lata. Accordingly, there are no reasonable ar- be used to separate fossil Amyocerata from guments to give the Zygentoma and Microco- Entogna tha. ryphia ranks of orders. Thus the extinct Palaeo- wic taxa - Monura and CarboMpllurina subordo n. Order THYSANURA (sensu Barrier, 1904) - are also regarded only as suborders rather than orders. = Ectotrophi Grassi & Rovelli, 1890; Ectognatha Stum- mer-Traunfels, 1891; Triplura Ewing, 1942. Suborder CARBOTRIPLURINA subordo n. Here the name "Thysanura" is accepted for Diagnosis. Body not depressed laterally (in the order including the suborders Zygentoma contrast to Microcoryphia and Monura) . Par- BBrner, 1904, Microcoryphia Verhoeff, 1904, aterga of abdominal segments turned laterally Monura Sharov, 1957 and other primarily (in contrast to all other Thysanura, where wingless Amyocerata. abdominal paraterga are pressed on the lateral The name "Thysanura" has been used in sides of sternocoxa). Cerci well developed (in several different meanings.If the taxa of the contrast to Monura) . same volume are assumed identical irrespective Composition. Monotypic. of their rank, the following synonymy can be given: Thysanura Latreille, 1796 (= Aptery- Family CARBOTRIPLURIDAE fam. n. gota Lang, 1889); Thysanura sensu Lubbock, 1873 (= Cinura Packard, 1883) ; Thysanura Diagnosis and composition. The same as in sensu B'drner, 1904 (= Ectotrophi Grassi & the suborder. Rovelli, 1890) ; Thysanura sensu Crampton, 1928 (= Zygentoma BiTrner, 1904). Genus Carbotriplura gen. n. Some authors regard Zygentoma and Micro- coryphia as separate orders, assuming that Zy- Type species Carbotriplurakukalovae sp. n. gentoma is the sister group of Pterygota, and therefore combine Zygentoma and Pterygota Diagnosis and composition. The same as in into the taxon Dicondylia Hennig, 1953. The the family and suborder. mandibular structure is considered to be the basic autapomorphy of Dicondylia. Mandibles Carbotriplura kukalovae sp. n. of Zygentoma (as well as of Pterygota) are described as "dicondylous", while mandibles = Bojophlebia procopi Kukalova-Peck, 1985, partim of Microcoryphia are described as "monocon- ("nymph", non "adult"): 936, Figs 4-10. dylous". Actually, if under the tern1 "condyle" we understand a sclerotized protuberance, we Holotypus. Specimen No. P27/80, Narodni Museum, Prague, CzechRepublic (paratypus of Bojophlebiapro- have to assume that mandibles of all Zygentoma copi Kukalova-Peck, 1985). Westphalian C, base of have no such "condyles" at all. If the term whetstone horizon, "Na Stilci" quarry near Tlustice, "condyle" means a point through which the Central Bohemian Coal Basin, Bohemia. (After Kuka- axis of rotation of mandible passes (inde- lova-Peck, 1985). pendently of the presence or absence of pro- Description. See Kukalova-Peck, 1985: 936, tuberances in these points), we are to conclude Figs 4-10. that both Zygentoma and Microcoryphia have two such "condyles" and a fixed axis of rota- Discussion tion determined by them: in Microcoryphia such points of attachment are the hind pro- Tergaliae and paraterga tuberance and the end of the internal transverse ridge, while in Zygentoma both points of at- Initially Carbotriplura kukalovae has been tachment have no special morphological struc- described as mayfly nymph because its strongly tures. It is well known that two condyles in the developed lateral abdominal projections were form of sclerotized protuberances are present regarded to be tergaliae (= "tracheal gills"), ZOOSYST.ROSSICA Vol. 4 N.Ju. Kluge: A new , suborder of Thysanura 73 the appendages typical of nymphs of Ephe- num and pleuron. In the primitive state each meroptera. Actually these projections are not tergalia has the anterior and posterior costae, tergaliae, but paraterga. with branched tergalial trachea between them; The term "tergalia" (plural - "tergaliae") was in contrast to wings, where tracheae are inside introduced for the homologous paired movable veins (which are tubular costae), tergalial tra- appendages present on abdomen in Ephemero- cheae never enter into costae. ptera larvae (independently of their function), In fossils of Ephemeroptera larvae (Fig. 2), while the term "tracheal gill" was left for tergaliae are clearly distinguishable from analogous organs of any origin, which are sup- processes of other kinds, since tergaliae are plied with tracheae and are used for aquatic always well separated from their segment: apart respiration (Kluge, 1989). The term "ter- from the margins of tergaliae, the lateral mar- galiae" is derived from the term "tergum", but gins of the segment are clearly visible. it does not imply that tergaliae have originated In contrast to the tergaliae of Ephemeroptera from parts of tergum: this word means only that larvae, the lateral abdominal projections of tergaliae are in all cases attached to tergum (as Carbotriplura (Fig. 1) are connected with the well as wings do), while the origin of tergaliae remainder of the tergum all along its length, the remains vague (as well as the origin of wings). anterior margin of each projection is at the As assumed by numerous authors, tergaliae same level as the anterior margin of its segment (which are present only on abdominal seg- (if they were be tergaliae, their anterior mar- ments) may be serial homologues of wings. gins should correspond to posterior margin of Tergaliae of Ephemeroptera larvae (nymphs) their segment). Apart from the margins of have the following features (Kluge, 1989). The lateral projections, no other lateral margins of most primitive and at the same time most com- segments are visible on the published photo- mon position of tergaliae attachment is on the graphs.