AUSTRALIAN MUSEUM SCIENTIFIC PUBLICATIONS Edgecombe, Gregory D., 1998. Early myriapodous arthropods from Australia: Maldybulakia from the Devonian of New South Wales. Records of the Australian Museum 50(3): 293–313. [25 November 1998]. doi:10.3853/j.0067-1975.50.1998.1288 ISSN 0067-1975 Published by the Australian Museum, Sydney naturenature cultureculture discover discover AustralianAustralian Museum Museum science science is is freely freely accessible accessible online online at at www.australianmuseum.net.au/publications/www.australianmuseum.net.au/publications/ 66 CollegeCollege Street,Street, SydneySydney NSWNSW 2010,2010, AustraliaAustralia Records of the Australian Museum (1998) Vo!. 50: 293-313. ISSN 0067-1975 Early Myriapodous Arthropods from Australia: Maldybulakia from the Devonian of New South Wales GREGORY D. EDGECOMBE Australian Museum, 6 College Street, Sydney South NSW 2000, Australia [email protected] ABSTRACT. The myriapodous arthropod Maldybulakia Tesakov & Alekseev, 1998, was first described from the Lower Devonian (Pragian-Emsian) in central Kazakhstan. The geographic and stratigraphic distributions of Maldybulakia are broadened by the discovery of Devonian species in Australia. The Lochkovian or Pragian Maldybulakia angusi n.sp. occurs in abundance in the Sugarloaf Creek Formation near Taemas, NSW. Maldybulakia malcolmi n.sp. occurs in late Givetian or early Frasnian strata of the Boyd Volcanic Complex near Eden, south coastal NSW. Two trunk tagmata are present in Maldybulakia. The strong tergal exoskeleton of posteriorly overlapping diplopleurotergites suggests closest affinities with Dignatha and, particularly, Kampecarida. Along with arthropleurids and kampecarids, Maldybulakia represents another major myriapod bodyplan in the mid-Palaeozoic. Although occurring in lacustrine and fluvial sediments, the associated flora, likely myriapod affinities, and presence of spiracles in Maldybulakia suggest terrestrial habits. EDGECOMBE, GREGORY D., 1998. Early myriapodous arthropods from Australia: Maldybulakia from the Devonian of New South Wales. Records of the Australian Museum 50(3): 293-313. Myriapods have a sparse fossil record prior to the had occurred by the Devonian. Among these is the Carboniferous Period (see Almond [1985] and Shear [1990] cladistically derived position of Middle Devonian for reviews of Silurian-Devonian body fossils). Among centipedes, which nest within some extant groups (Shear extant myriapod groups, millipedes and centipedes are & Bonamo, 1988). Further, the Upper Silurian occurrence known to have evolved by the Pffdolf (Upper Silurian) of Diplopoda predicts that the other extant lineages in the (Almond, 1985; Shear et al., 1998). Myriapodous fossils Progoneata and Dignatha, the Symphyla and Pauropoda, range back to the Lower Silurian (Mikulic et aI., 1985a,b), had diverged by that time (Kraus & Kraus, 1994). but the systematic position of these forms is uncertain. Except for trace fossil indications (Trewin & McNamara, The extinct Class Arthropleuridea, best represented in the 1995), all that is known about Silurian-Devonian Upper Carboniferous (Briggs & Almond, 1994), extends myriapods has come from the northern hemisphere, and back to the Pffdolf, with new Devonian occurrences in particular the Old Red Continent. The only citation of recently coming to light (Shear & Selden, 1995; Shear et mid-Palaeozoic myriapods from Gondwana has been al., 1996). In spite of the patchy fossil record, several fraught with controversy. Bergstrom (1979: 9-10) factors indicate that the major events in myriapod evolution mentioned "un described myriapod material from the 294 Records of the Australian Museum (1998) Vol. 50 Silurian of Australia", but Almond (1985) cited the view Wyborn, 1979). The fossils occur as totally disarticulated of H.B. Whittington that this material was actually moulds in fine-grained sandstones rich in volcanic rock Devonian and its myriapod affinities were highly question­ grains derived from the underlying Mountain Creek able. The present work documents this controversial Volcanics. No other animal fossils have been found material and provides a formal taxonomy based on associated with M. angusi (only very rare plant fragments), extensive new collections. yet this single species is sufficiently abundant as to locally H.B. Whittington (pers. comm., 1994, 1995) informed litter bedding surfaces. The depositional environment of me that the enigmatic fossils in question were shown to the arenites in the eastern extent of the Sugarloaf Creek him by K.S.W. Campbell. Campbell revealed that these Formation has been interpreted as fluvial (Owen & arthropods were collected from an Early Devonian site in Wyborn, 1979). Although fossils were not previously the Taemas-Wee Jasper district, New South Wales, and led recognised from the Sugarloaf Creek Formation, a latest a trip to the locality in 1995. Disarticulated sclerites of a Lochkovian to earliest Pragian age assignment was made large, apparently myriapodous, arthropod were found in by Owen & Wyborn (1979) based on an early Pragian the Sugarloaf Creek Formation in an abundance rivaled dating for the conformably overlying Cavan Limestone. by few fossil myriapod sites. The species is described here The age of the Cavan Formation has, however, been as Maldybulakia angusi n.sp. Also in 1995, Alex Ritchie reassessed based on conodonts (Mawson et al., 1992), its informed me of a Devonian site from which he had lower part representing the late Pragian pireneae Zone. collected parts of a myriapodous arthropod near Eden on The Sugarloaf Creek Formation is thus less constrained the south coast of New South Wales. Collecting at this within the Lochkovian-Pragian interval. locality revealed a second species of Maldybulakia Tesakov Maldybulakia malcolmi is common through an & Alekseev, 1998, and showed the genus to range into the approximately 30 cm interval in mud stone and silts tone at Middle or Upper Devonian. This second species is named an outcrop along Saltwater Creek Forest Road, near Edrom, Maldybulakia malcolmi n.sp. 12 km SSE of Eden. The site (37°09'S 149°57'E) is located The Australian species are considered congeneric with 3.6 km from the intersection of Saltwater Creek Road and the enigmatic myriapodous taxon Maldybulakia mirabilis Edrom Road in East Boyd State Forest (Fig. ID). Fergusson (Tesakov & Alekseev, 1992), from the Lower Devonian of et al. (1979: fig. 5) documented this section as examplar central Kazakhstan. The new material adds considerable of lacustrine mudstones in their Facies 3 of the Boyd clarity to the nature of tagmosis in this arthropod, and sheds Volcanic Complex. They noted the occurrence of more light on the affinities of Maldybulakia. While Tesakov Maldybulakia [as "Arthropods (unidentified genus)"] with & Alekseev (1992) employed descriptive terminology used lycopods, which are abundantly represented at these levels. for millipedes, they made no more precise systematic Some of these can be identified as Lepidosigillaria placement for the genus than to regard it as myriapod­ yalwalense, usually regarded as Middle Devonian in age like. Material at both Australian localities consists of trunk (M.E. White, pers. comm., 1995). However, bothriolepid tergites and pleurotergites alone (the sternum and limbs and phyllolepid placoderms indicative of a Givetian­ were clearly less mineralised, and unpreserved). The heads Frasnian age are known from Facies 3 of the Boyd Volcanic of all three species are unknown. Tesakov & Alekseev Complex at other localities (Fergusson et al., 1979; G.C (1992) interpreted the trunk tergites of Maldybulakia as Young, pers. comm., 1996). The same flora occurs with diplosegments, divided into prozonites and metazonites. I late Givetian or early Frasnian fish in Facies 2 of the Boyd have accepted this interpretation in describing the Volcanic Complex (Bunga Beds). On this evidence, Australian species, for reasons elaborated below. Maldybulakia malcolmi can be assigned an age in the late Specimens illustrated in this work are housed in the Givetian to early Frasnian interval. The site was extensively Palaeontology type collections of the Australian Museum excavated in April 1997 by the author and 11 other (prefixed AM F). collectors. Both Australian species of Maldybulakia are thus known from sediments deposited in fresh water, and disarticulated Occurrences tergites and pleurotergites occur as rich accumulations. The geological and inferred ecological context of M. Localities, environments, and ages. Maldybulakia is at mirabilis in Kazakhstan is similar. The latter species occurs present known from two localities in the Devonian of New as abundant, mostly disarticulated, moulds in beds of South Wales (Fig. 1). tuffaceous siltstone. Tesakov & Alekseev (1992) regarded Maldybulakia angusi occurs in the Sugarloaf Creek the depositional setting of these sediments as lacustrine, Formation, near the eastern outcrop limit of the formation. similar to the interpretation of mudstones bearing M. The site (35°04'S 148°51'E) is located about 400 m east of malcolmi (Fergusson et al., 1979; P.C Lewis et al., Mountain Creek Road, and is accessed 400 m south of 1994). Maldybulakia is, however, likely to have been Three Oaks homestead (Fig. 1C). The Sugarloaf Creek terrestrial rather than aquatic, based on the inferred Formation consists of massive, lenticular arenites deposited presence of a tracheal respiratory system (see interpretation in alluvial fans in the western part of the outcrop