Riek (Reference Riek1952) described a new genus with one species, Austropanorpa australis Riek, Reference Riek1952, based on two incomplete forewings from the Tertiary of Queensland, Australia. This taxon was considered to be a new member of the family Panorpidae. Additional remarks on this taxon, based on a hind wing (part and counterpart) from the same locality and horizon, were provided by Riek (Reference Riek1967).
Willmann (Reference Willmann1977) extensively discussed the morphological characters of A. australis and concluded that this taxon should be excluded from the family Panorpidae. He established (Willmann Reference Willmann1977) a new family, Austropanorpidae, which he considered to be a sister taxon to Panorpidae + Panorpodidae, based on the character of four medial veins in the forewing. Willmann (Reference Willmann1987, Reference Willmann1989) additionally discussed the position of the family Austropanorpidae within the phylogenetic system of Mecoptera. Subsequently, Novokshonov (Reference Novokshonov, Rasnitsyn and Quicke2002) recognised Austropanorpidae as a tentative synonym of the family Orthophlebiidae. However, Archibald et al. (Reference Archibald, Mathewes and Greewood2013) followed Willmann's (Reference Willmann1977) conception and accepted Austropanorpidae as a separate family. According to Willmann (Reference Willmann1987), Austropanorpidae, along with the families Orthophlebiidae, Muchoriidae, Panorpidae, Panorpodidae, Holcorpidae and Dinopanorpidae, formed the superfamily Panorpoidea. Archibald et al. (Reference Archibald, Mathewes and Greewood2013) added a new family to this group, Eorpidae.
During the taxonomic and phylogenetic investigation of the family Orthophlebiidae by the present authors, the species Orthophlebia martynovae Sukatsheva, Reference Sukatsheva and Rasnitsyn1985 was revised. It was found that the holotype of this species described from the Lower Jurassic of Siberia resembles A. australis. As a result, we have transferred O. martynovae to the family Austropanorpidae as Austopanorpa martynovae (Sukatsheva) comb. nov. An updated description of the family Austropanorpidae is provided.
1. Material and methods
The study was based on the restudied holotype of Orthophlebia martynovae Sukatsheva, Reference Sukatsheva and Rasnitsyn1985, N. 1588/67, housed in the Paleontological Institute, Russian Academy of Sciences in Moscow (PIN). The fossil was found at Iya, also known as Vladimirovka, one of numerous insect sites within the Cheremkhovo (= Cheremkovskaya) Formation of the Irkutsk Basin in Siberia (Russia). This locality is described in detail in Rasnitsyn & Quicke (Reference Rasnitsyn and Quicke2002, pp 440, 443), Rasnitsyn (Reference Rasnitsyn1985, p. 7) and in sketch maps in Kolosnitsyna (Reference Kolosnitsyna1964, Reference Kolosnitsyna1982). According to Akulov et al. (Reference Akulov, Frolov, Mashchuk and Akulova2015), it is dated as Early Jurassic, Toarcian, 174.1–182.7 MA (Cohen et al. Reference Cohen, Finney and Gibbard2013). The redescription of Austopanorpa australis Riek, Reference Riek1952 is based on the original drawing and descriptions of the species by Riek (Reference Riek1952, Reference Riek1967) and Willmann (Reference Willmann1977) and on new photographs made by Geoff and Russell Thompson from the Queensland Museum. Both the holotype (UQF10634/10635) and paratype (UQF10636/10637) of Austropanorpa australis are in the collection of the Queensland Museum in Australia. All known specimens (two forewings and one hind wing) are housed in the Geology Department, University of Queensland, and were collected from the Tertiary Redbank Plains Series of Redbank Plains, near Goodna, Queensland, Australia.
The specimen of O. martynovae was studied with the use of a stereomicroscope, under reflected light. Drawings were based on the photographs and digitally processed in Corel X5. The terminology of wing venation follows Willmann (Reference Willmann1989), with some modifications (Soszyńska-Maj et al. Reference Soszyńska-Maj, Krzemiński, Kopeć and Coram2017 (this volume)).
2. Systematic palaeontology
Order Mecoptera Packard, Reference Packard1886 Superfamily Panorpoidea Latreille, Reference Latreille1805 Family Austropanorpidae Willmann, Reference Willmann1977
Type genus. Austropanorpa Riek, Reference Riek1952, p. 11, fig. 2 – Tertiary, Redbank Plains Series, Redbank Plains, Queensland, Australia.
Composition. One genus, Austropanorpa Riek, Reference Riek1952, with two species included.
Emended diagnosis. Distinguished from all other families by a combination of the following characters: Rs1 pectinate in both wings, radial sector (Rs) with nine veins reaching the outer margin, Rs2, Rs3 and Rs4 single, four medial veins in fore- and hind wings.
Redescription. Wings length 18–25 mm, with colour markings; vein Sc long in forewing, reaching pterostigmal area, shorter in hind wing, reaching outer margin opposite the end of M4; Rs1+2 2–2.5 times longer than Rs in forewing and about 1.5 times longer in hind wing; Rs1 pectinate, forks on six single veins reaching outer margin in both wings; Rs2 single; Rs3+4 significantly shorter than Rs1+2, forks to two single veins reaching wing margin; four medial veins only in both wings; M1+2 a few times longer than M3+4.
Remarks. Description based on four known specimens (wings): of which three (two forewing and one hind wing) belong to one species, A. australis, and one hind wing to A. martynovae comb. nov. The paratype forewing of Austropanorpa australis (F. 10336, part and F. 10337, counterpart) described by Riek (Reference Riek1952, p. 11, fig. 3) is not fully preserved and only eight veins are apparent in the radial sector. Nine radial veins reaching the wing margin are characteristic for the genus Austropanorpa and it is likely the damaged paratype wing also originally had nine radial veins, like the holotype. All specimens have only four longitudinal medial veins reaching the outer margin in both wings. This supports Willmann's (Reference Willmann1977) conclusion that this is a stable character for the family Austropanorpidae.
Genus Austropanorpa Riek, Reference Riek1952
Type species. Austropanorpa australis Riek, Reference Riek1952, p. 11, Eocene, Redbank Plains Series, Redbank Plains, Queensland, Australia.
Composition. Currently two species belong to this genus: the type species and Austropanorpa martynovae (Sukatsheva, Reference Sukatsheva and Rasnitsyn1985) comb. nov., from the Lower Jurassic of Siberia.
Diagnosis. As for family by monotypye.
Redescription. As for family by monotypye.
Austropanorpa australis Riek, Reference Riek1952 (Figs 1, 2)
Wings of Austropanorpa australis Riek, Reference Riek1952: (A) forewing, holotype F. 10634A; (B) forewing, holotype F. 10634B; (C) forewing, paratype F. 10336 (from new photographs); (D) hind wing F. 15572A (redrawn from Riek Reference Riek1967). Scale bars = 1 mm.
Photographs of Austropanorpa australis Riek, Reference Riek1952, forewing: (A) holotype F. 10634A; (B, C) holotype F. 10634B, counterpart (in two pieces); (D, E) paratype F. 10336, part and counterpart. (photos Geoff & Russell Thompson).
Material. Holotype no. F. 10634, part and F. 10635, counterpart, forewing with distal part missing; paratype no. F. 10336, part and F. 10337, counterpart, with basal part not preserved; housed in the University of Queensland, Department of Geology Collection. Hind wing no. F. 15572A, part and F. 15572B, counterpart, with small basal part missing.
Diagnosis. Membrane of the wing transparent with narrow, elongated dark spots; forkings of Rs1+2, Rs3+4 and Mb do not lie along the same line in hind wing.
Redescription. Wing c.25 mm length, with elongated, narrow dark markings; Sc long in the forewing, reaching the outer margin at pterostigmal area; Sc in the hind wing short and reaching the outer margin slightly before M4 ends; R1 long in forewing, ending significantly beyond the last forking of Rs1, R1 in hind wing shorter, with two branches, reaching the outer margin before last forking of Rs1; in forewing Rs short, vein Rs1+2 twice as long as Rs and almost half the length of vein Rs1 before first forking; in hind wing vein Rs is not preserved; Rs1 pectinate with six single longitudinal veins in both wings; forkings Rs1+2, Rs3+4 and Mb lie along the same diagonal line in the forewing, but do not lie along the same line in the hind wing; in forewing Rs3+4 forks in one third of M1+2, in hind wing in two thirds of M1+2; M1+2 almost four times longer than M3+4; M1 ca. twice as long as M1+2, M3 six times longer than M3+4.
Austropanorpa martynovae (Sukatsheva, Reference Sukatsheva and Rasnitsyn1985) (Fig. 3)
Austropanorpa martynovae (Sukatsheva, Reference Sukatsheva and Rasnitsyn1985) comb. nov., hind wing, holotype N. 1588/67: (A) drawing; (B) photograph.
Orthophlebia martynovae Sukatsheva, Reference Sukatsheva and Rasnitsyn1985, p. 102, fig. 8.
Material. Holotype N. 1588/67 housed in PIN, from Iya, Cheremkhovo (= Cheremkovskaya) Formation of the Irkutsk Basin, Siberia, Russia, dated as Early Jurassic, Toarcian, 174.1–182.7 MA (Akulov et al. Reference Akulov, Frolov, Mashchuk and Akulova2015).
Diagnosis. Membrane of the wing transparent, with dark, wide bands; forking of Rs1+2, Rs3+4 and Mb lie almost along the same line in hind wing.
Redescription. Only a single hind wing known, c.18 mm length, with elongated, wide, dark clearly visible bands; Sc ends opposite one quarter of length of Rs1a+b; R1 reaching outer margin opposite the point where M2 reaches the outer margin; Rs one third shorter than Rs1+2 and equal in length to Rs3+4; forkings of Rs1+2, Rs3+4 and Mb lie almost along the same line; Rs1 pectinate, with six single, longitudinal veins; M1+2 about 2.5 times longer than M3+4; M1 about 2.5 times longer than M1+2, M3, five times longer than M3+4.
Remarks. Diagnosis based on the hind wing only, as forewing is not known for this species.
3. Discussion
The wing venation of the family Austropanorpidae displays a specific pattern not seen in any other mecopteran family. In both wings, the radial sectors are nine-branched and the medial sectors have four veins. The initial inclusion of this taxon in the family Panorpidae (Riek Reference Riek1952) was rejected by Willman (1977), who erected a new family, Austropanorpidae, since all representatives of Panorpidae + Panorpodidae, both fossil and extant, have radial sectors which are five- or, exceptionally, six-branched, including the oldest Panorpidae, Jurassipanorpa inpunctata (Ding et al. Reference Ding, Shih, Bashkuev, Zhao and Ren2014). Willmann (Reference Willmann1977) considered the similarity of the medial sector, including the reduction of one medial vein in the forewing, to be either a symplesiomorphy (with Panorpidae + Panorpodidae as sister taxon to Austropanorpidae), or a homology which evolved independently. A pectinate Rs1 is characteristic for Orthophlebiidae, leading to Austropanorpodes martynovae comb. nov. originally being described as an orthophlebiid (Sukatsheva Reference Sukatsheva and Rasnitsyn1985). However, Orthophlebiidae is now considered to be a paraphyletic stem group of the Panorpoidea (Willmann Reference Willmann1989). Thus, the loss of M4b in the forewing could have happened more than once in orthophlebiids and this wing might, also, be only convergently similar to the Austropanorpidae. However, this requires further study and new fossil material.
In addition to issues of wing venation, Willmann (Reference Willmann1977) also stressed the differences in the geographic distribution of Panorpidae, Panorpodidae and Austropanorpidae. Panorpidae has a disjunctive holarctic distribution, with some representatives in the oriental region (Archibald et al. Reference Archibald, Mathewes and Greewood2013) and, to date, there is no fossil evidence for a wider past distribution (Krzemiński & Soszyńska-Maj Reference Krzemiński and Soszyńska-Maj2012; Ding et al. Reference Ding, Shih, Bashkuev, Zhao and Ren2014). The distribution of extant Panorpodidae is limited to a small area of the Northern Hemisphere (Byers Reference Byers2005; Zhang Reference Zhang2011). Until now, the only fossil evidence of panorpodids has been from Eocene Baltic amber (Carpenter Reference Carpenter1954; Soszyńska-Maj & Krzemiński Reference Soszyńska-Maj and Krzemiński2013, Reference Soszyńska-Maj and Krzemiński2015). The affinity of one species from the Eocene of South America, Austropanorpodes gennaken Petrulevičius, Reference Petrulevičius2009, to Panorpodidae is not strongly supported (Soszyńska-Maj & Krzemiński Reference Soszyńska-Maj and Krzemiński2015). Previously, Austropanorpidae were known only from Australia, and a revision of the species Austropanorpa martynova comb. nov. extends their known distribution into the Northern Hemisphere. Willmann (Reference Willmann1977) argued that the geographical isolation of these families supported the conclusion that the four-branched medial vein in the forewing is a homology in Austropanorpidae and Panorpidae + Panorpodidae. Willmann (Reference Willmann1977) suggested that the stem group of these three families most likely comprised Orthophlebiidae, which were widely distributed in Eurasia and Australia, from which a lineage, including Austropanorpidae, separated in the Late Triassic.
Our paper improves knowledge about Austropanorpidae distribution. Currently, we have evidence of this family in the Jurassic of Siberia and in the Eocene of Australia. This is, therefore, not an endemic but a relictual family in Australia, which probably evolved before the break-up of Pangaea. It leads to the conclusion that of the closely related families grouped together into Panorpoidea (Willmann Reference Willmann1987; Archibald et al. Reference Archibald, Mathewes and Greewood2013), not only Orthophlebidae but also Austropanorpidae were distributed more widely. However, of all Panorpoidea families, only Panorpodidae and Panorpidae have survived from the Eocene apex of Panorpoidea diversity (sensu Willmann Reference Willmann1987) until the present (Archibald et al. Reference Archibald, Mathewes and Greewood2013).
4. Acknowledgements
We are very grateful to Aleksandr Rasnitsyn and Alexey Bashkuev for their help and heated discussions during our stay in the Paleontological Institute, Russian Academy of Sciences in Moscow, and for their help with geology of the Iya locality. Special acknowledgements are due to Kristen Spring, Collection Manager in Queensland Museum Geosciences Collections, who helped us with the new photographs and enabled the study of the holotype of Austropanorpa australis. The copyright of the photographs of Austropanorpa australis belongs to the Queensland Museum, Australia. We thank Robert Coram for improving the English version of the manuscript. The research was fully supported by the Polish National Science Center (grants no.2013/09/B/NZ8/03270).
