Search

Metopolichas Gürich, 1901 Type species. Metopias Hubneri Eichwald 1842, Tallinna Limestone, Estonia. See Thomas & Holloway 1988, p. 214., Published as part of Fortey, Richard A., Wernette, Shelly J. & Hughes, Nigel C., 2022, Revision of F. R. C. Reed's Ordovician trilobite types from Myanmar (Burma) and western Yunnan Province, China, pp. 301-356 in Zootaxa 5162 (4) on page 348, DOI: 10.11646/zootaxa.5162.4.1, http://zenodo.org/record/6810290, {"references":["Gurich, G. (1901) Ueber eine neue Lichas - Art aus dem Devon von Neu-Sud-Wales un uber die Gattung Lichas uberhaupt. Neues Jahrbuch fur Mineralogie, Geologie und Palaontologie, Beil-agebande, 14, 519 - 539.","Eichwald, C. E. V. (1842) Die Urwelt Russlands durch Abbildungen erlautert. Part 2. Druckerei des Journal de Saint-Petersbourg, St Petersburg, 184 pp.","Thomas, A. T. & Holloway, D. J. (1988) Classification and phylogeny of the trilobite order Lichida. Philosophical Transactions of the Royal Society of London, Biological Sciences, 321, 179 - 262. https: // doi. org / 10.1098 / rstb. 1988.009"]}

The field collections made from Burma (Myanmar) by the Geological Survey of India, and described by F.R.C. Reed more than a century ago, still provide the only ‘ground truthing’ for an important region of the Ordovician marginal terranes fringing Gondwana. A revision of these faunas is overdue, particularly as it is likely that further collections cannot be made in the northern Shan State in the near future. The specimens, stored in the Geological Survey of India collections in Kolkata, cannot be loaned. Sixteen species are fully revised herein; another twelve species are left under open nomenclature because of inadequacies in the material. Several of Reed’s species subsequently became type species of genera that have proved to be widespread: Birmanites Sheng, 1934, Encrinurella Reed, 1915, Neseuretinus Dean, 1967, and Pliomerina Chugaeva, 1956. Reed’s Ordovician trilobite collections came from two main areas: northern Shan State (Myanmar), and westernmost Yunnan (China). The Burmese (Myanmar) collections are from the Upper Ordovician (Katian) while Yunnan specimens are from the Middle Ordovician (Darriwilian), though Upper Ordovician trilobites also occur in the area. Both collections are predominantly from clastic strata. Based on a small new Katian collection from Pupiao, we report Neseuretinus birmanicus (Reed, 1906) in common between the northern part of the Shan State and western Yunnan. A few genera (Dionide Barrande, 1847, Phorocephala Lu, 1957, Lonchodomas Angelin, 1854, Nileus Dalman, 1827) are distributed worldwide, and include pelagic (Phorocephala) or deeper benthic (Dionide) taxa. The palaeogeographic comparisons offered by the other taxa are mostly peri-Gondwanan and extend from southwest China westwards (present geography) as far as the Iberian Pennsula. Birmanites is the type genus of a subfamily (Birmanitinae Kobayashi, 1960, revived herein) widely distributed over Ordovician Gondwana, and absent from Laurentia, Baltica and North China/Siberia. Mioptychopyge Zhou, Dean, Yuan & Zhou, 1998, probably belongs with the same group and is otherwise known from South China. Parillaenus Jaanusson, 1954, is also peripheral Gondwanan, as is Prionocheilus Rouault, 1847. The Reedocalymeninae Kobayashi, 1951 (Neseuretinus, Reedocalymene Kobayashi, 1951) are similarly diagnostic of peri–Gondwanan sites. However, some genera (Pliomerina, Encrinurella, Ovalocephalus Koroleva, 1959) have been associated with other oriental and Australian occurrences in particular, with ‘outliers’ in certain terranes in Kazakhstan, i.e. palaeotropical Gondwana.

Budil, Petr, Mergl, Michal (2019): Trilobite Assemblage Of Calceola -Bearing Beds In Acanthopyge Limestone (Choteč Formation, Middle Devonian, Eifelian, Prague Basin, The Czech Republic). Fossil Imprint 75 (1): 79-91, DOI: 10.2478/if-2019-0007, URL: http://dx.doi.org/10.2478/if-2019-0007

Paraacidaspis ? priscilla (��pik, 1967) Fig. 19 1967 Saukia ? priscilla; ��pik, p. 250���251, pl. 30, figs 5���7. Material. Six pygidia figured, CPC42330���CPC42335. Four pygidia not figured (mostly fragments). Description. Pygidium up to 5 mm long (sag.), semicircular, only slightly convex, length:width ratio of 65%. Anterior margin slightly arched forward. Posterior margin broadly rounded, slight anterior inflection in margin medially near the postaxial ridge. Axis prominent, moderately narrow (tr.), tapering posteriorly, width:length ratio of 71%; small, occupying about 60% of sagittal length of pygidium. Articulating half-ring narrow (sag.), defined by narrow (sag.), shallow articulating furrow. Five moderately well developed to faint axial rings present, separated by shallow, narrow (sag.) inter-ring furrows. Terminal piece small. Long (sag.), postaxial ridge continues from the terminal piece until just before the posterior border, ridge the same width (tr.) as the terminal piece. Axial furrow deep and narrow (tr.), fading around terminal piece. Pleural regions slightly convex, with five narrow (exsag.), shallow pleural furrows that terminate just before reaching margin; pleural furrows directed posterolaterally; five distinct, shallow, narrow (exsag.) interpleural furrows present, following the same course as pleural furrows, dividing the pleura into a slightly narrower (exsag.) anterior band and a wider (exsag.) posterior band. Border not well defined. Prosopon over pygidium of fine pustules. Cephalon, hypostome, rostral plate and thorax unknown. Discussion. The pygidia from the Goyder Formation are almost identical to those reported as Saukia ? priscilla by ��pik (1967) from the Mindyallan O���Hara Shale and Georgina Limestone in the Georgina Basin. Both show a semicircular outline, a short axis, five axial rings (see Opik 1967, pl. 30, fig. 7), a long (sag.) postaxial ridge, five narrow (exsag.) pleural and interpleural furrows, pleurae divided into a narrow anterior and wide posterior bands, no pygidial border, and a fine pustulose ornament. The only minor difference is that the Georgina Basin pygidia lack the subtle indentation in the posteromedial margin, immediately behind the postaxial ridge. These slight variations are more likely to be preservational, since two of the three Georgina Basin specimens do not have a complete posterior margin. ��pik (1967) tentatively assigned the material from the Georgina Basin to Saukia Walcott, 1914. This assignment was largely based on the presence of five axial rings and five pleural furrows, which ��pik (1967) suggested was similar to both Saukia and Tellerina Ulrich & Resser, 1933. The pygidia illustrated here and by ��pik (1967) are unlikely to belong to either of these genera, since Saukia and Tellerina typically have a shorter postaxial ridge, and shorter (tr.) pleural and interpleural furrows. A more compelling comparison can be made with Paraacidaspis, especially P. hunanica Egorova in Poletaeva, 1960 and Paraacidaspis sp. (Peng et al. 2004a) from the Guzhangian of South China, and P. ultima Shergold, Feist & Vizcaino, 2000 from the Guzhangian���Paibian of southern France. Paraacidaspis hunanica and P. ultima have essentially identical pygidia and both are similar to those from the Goyder Formation and ��pik���s (1967) Georgina Basin material. Paraacidaspis sp. described by Peng et al. (2004a) also has a similar pygidium, although it has a more coarsely granulose prosopon making it immediately distinguishable from the material reported herein. The Goyder Formation and Georgina Basin material differs from these previously described species in possessing the following features: a slightly longer (sag.) axis, narrower anterior pleural bands, and wider posterior pleural bands. These minor differences are likely of only interspecific significance, hence, Saukia ? priscilla ��pik, 1967 is questionably reassigned to Paraacidaspis. Similar pygidia have been described from the Boomerangian to Idamean Spurs Formation in Antarctica. The pygidium assigned to Nganasanella ? sp. by Cooper et al. (1996, fig. 5U) is small and incomplete, but is comparable to the Goyder Formation material. Only minor differences are apparent, including a shorter (sag.) axis and a relatively wider anterior pleural band. Coosia ? sp. 2 illustrated by Jago & Cooper (2005, fig. 6S) has a similar outline to the Goyder Formation species, but possesses more pleural and interpleural furrows than the Goyder Formation pygidia. The pygidium of Coosia ? sp. 1 illustrated by Jago & Cooper (2005, fig. 6R) differs from the Goyder Formation specimens in having a more subcircular outline, narrower (tr.) axis, wider (exsag.) anterior pleural band, and a longer (sag.) terminal area. Material described by Bentley et al. (2009, figs 7K, L, 8U) as Coosia ? sp. also differs in having wider anterior pleural bands and a longer (sag.) terminal area. Given these relatively minor differences, it is possible that the Antarctic taxon���following the synonymy of Bentley et al. (2009, p. 183)���represents a new species of Paraacidaspis. Another similar pygidium, identified as? Paraacidaspis sp., was described from the Guzhangian of Sweden by Żylińska et al. (2015). This specimen differs from previously described taxa, including Paraacidaspis ? priscilla (��pik, 1967), in possessing a subrectangular outline, only four pleural furrows, and a narrower (tr.) postaxial ridge. Occurrence. GOY section horizons 73.2 and 83.9 m (Fig. 3) and at AS 168. Distribution. Goyder Formation, Amadeus Basin, Northern Territory. O���Hara Shale and Georgina Limestone, Georgina Basin, Northern Territory and Queensland. All occurrences are Cambrian Series 3, Guzhangian (Mindyallan) in age., Published as part of Smith, Patrick M., Paterson, John R. & Brock, Glenn A., 2018, Trilobites and agnostids from the Goyder Formation (Cambrian Series 3, Guzhangian; Mindyallan), Amadeus Basin, central Australia, pp. 1-67 in Zootaxa 4396 (1) on pages 39-40, DOI: 10.11646/zootaxa.4396.1.1, http://zenodo.org/record/1202723, {"references":["Walcott, C. D. (1914) Dikelocephalus and other genera of the Dikelocephalidae. Smithsonian Miscellaneous Collections, 64, 157 - 258.","Ulrich, E. O. & Resser, C. E. (1933) The Cambrian of the Upper Mississippi Valley. Part 2: Saukiinae. Bulletin of the Public Museum of Milwaukee, 12, 123 - 306.","Poletaeva, O. K. (1960) Novye rody i vidy kembriyskikh trilobitov zapadnoy Sibiri. Trudy Sibirskiy Nauchno-issledovat'skiy Institut Geologiy, Geofiziki i Mineral'nogo Syr'ya (SNIIGGIMS), 8, 67 - 71. [in Russian]","Shergold, J. H., Feist, R. & Vizcaino, D. (2000) Early Late Cambrian trilobites of Australo-Sinian aspect from the Montagne Noire, southern France. Palaeontology, 43, 599 - 632. https: // doi. org / 10.1111 / 1475 - 4983.00142"]}

Blackwelderia Walcott, 1906 Type species. Calymene ? sinensis Bergeron, 1899. Discussion. This genus has been discussed exhaustively by numerous authors (e.g., Walcott 1913; Kobayashi 1942; Lu et al. 1965; ��pik 1967; Park et al. 2013), yet the concept of the genus is still poorly understood. Park et al. (2013) suggested that this problem stems from a number of species erected on poorly preserved specimens, including the lectotype for Blackwelderia sinensis (Bergeron, 1899), which come from weathered shale material in North China (see Peng et al. 2004a; Peng 2007). Such incomplete or poorly preserved specimens has led to taxonomic confusion with morphologically similar genera such as Damesella Walcott, 1905 and oversplitting of Blackwelderia (see Wang et al. 1989; Zhu & Wittke 1989; Guo et al. 1996 for expansive species lists). Park et al. (2013) suggested that a detailed morphological and taxonomic assessment of Blackwelderia is required to resolve the generic concept., Published as part of Smith, Patrick M., Paterson, John R. & Brock, Glenn A., 2018, Trilobites and agnostids from the Goyder Formation (Cambrian Series 3, Guzhangian; Mindyallan), Amadeus Basin, central Australia, pp. 1-67 in Zootaxa 4396 (1) on page 22, DOI: 10.11646/zootaxa.4396.1.1, http://zenodo.org/record/1202723, {"references":["Walcott, C. D. (1906) Cambrian faunas of China. Proceedings of the United States National Museum, 30, 563 - 595. https: // doi. org / 10.5479 / si. 00963801.1458.563","Walcott, C. D. (1913) The Cambrian faunas of China. Research in China. Carnegie Institution of Washington, 54, 3 - 276.","Walcott, C. D. (1905) Cambrian faunas of China. Proceedings of the U. S. National Museum, 29, 1 - 106. https: // doi. org / 10.5479 / si. 00963801.1415","Wang, Q., Mills, K. J., Webby, B. D. & Shergold, J. H. (1989) Upper Cambrian (Mindyallan) trilobites and stratigraphy of the Kayrunnera Group, western New South Wales. BMR Journal of Australian Geology & Geophysics, 11, 107 - 118."]}

Blackwelderia repanda ��pik, 1967 Figs 10, 11 1967 Blackwelderia repanda; ��pik, p. 315���316, pl. 32, fig. 2, pl. 47, fig. 10. 1989 Blackwelderia sp. cf. B. repanda ��pik; Wang, Mills, Webby & Shergold, p. 114���115, figs. 4R���T, 5A���I.?2007 Blackwelderia sp. cf. B. repanda ��pik; Shergold, Laurie & Shergold, p. 31���32, fig. 11A���F. Material. Ten cranidia, three librigenae, two hypostomes and twelve pygidia figured, CPC42243���CPC42268. 26 cranidia, 62 librigenae, nine hypostomes and 102 pygidia not figured (mostly fragments). Description. Cephalon transversely subovate, up to 11 mm long (sag.). Cranidium trapezoidal in outline, length:width ratio approximately 53%, maximum width across posterior limbs of fixigenae, narrowest point of cranidium at the anterior margin; strongly convex (sag., tr.). Anterior margin straight (tr.). Posterior margin bowed anteriorly, except for the occipital ring that bulges posteriorly. Anterior branches of facial suture (�������) are difficult to distinguish. Glabella long (sag.), anteriorly truncate, trapezoidal in outline, strongly convex, with maximum convexity across midwidth, lateral slopes gently convex; width:length ratio of 71% to 74% (mean 72%; n = 3), occupying 89% of the cranidial length. Axial furrow narrow (tr.) and deep. S1 well defined, deep and narrow (exsag.), intersecting axial furrow approximately level with ε, directed slightly posteromedially for a short distance, before bifurcating with the anterior branch traversing a small distance anteromedially before becoming indistinct and the posterior branch continuing posteromedially. S2 and S3 short; S2 is directed posteromedially, whilst S3 is directed anteromedially. Occipital ring of moderate length (sag.), becoming slightly narrower abaxially, posterior margin strongly bowed backwards. SO wide (exsag.), straight to slightly bowed backwards medially in some individuals, moderately deep (sag.) and deepening abaxially. Anterior cranidial border narrow (sag.), moderately convex, slightly upturned. Anterior border furrow deep and wide (sag., exsag.), with deeper (possibly apodemal) pits situated at the anterolateral corners of the glabella. Preocular field, strongly convex, strongly downsloping toward the anterior border furrow, 21% of sagittal cranidial length between the anterior border and ��. Palpebral lobes reniform in outline, defined by a narrow (tr.), shallow palpebral furrow, anterior tip situated opposite S2, posterior tip situated opposite L1. Eye ridge weakly defined on external surface, slightly more defined on exfoliated surfaces, extending posterolaterally from just anterior to S 2 in a slightly anteriorly curved line towards the anterior tip of palpebral lobe. Palpebral area of fixigena slightly convex, downsloping towards the axial furrow, maximum width (tr.) is adjacent to 92% of the glabellar width. Postocular field moderately long (exsag.) and strongly downsloping toward the posterior border furrow. Posterolateral projections of fixigena strongly downsloping. Posterior border narrow (exsag), widening abaxially, separated from fixigenal field by deep, wide (exsag.) border furrow. Posterior border furrow straight proximally, then directed posterolaterally to ε. Hypostome of moderate size, up to 5 mm in length (sag.), strongly convex (sag., tr.), anterior margin weakly curved, lateral margins concave anteriorly and convex posteriorly, posterior margin strongly rounded. Middle body anterior lobe strongly convex and ovate. Posterior lobe moderately convex, narrow (sag., exsag.), strongly crescentic; anterior wings short (tr.), subtriangular in outline. Middle furrow slit-like and shallow. Librigena up to 10 mm in length excluding spine. Lateral margin, including that of genal spine, moderate to strongly curved anteriorly. Posterior margin curved slightly forward distally before abruptly curving rearwards to become the inner margin of the genal spine. Genal field subtrapeziform, 75% of librigenal width (tr.) along posterior border, moderately convex. Lateral border moderately well defined, widest near the posterior border. Lateral and posterior border furrows wide (exsag.) and moderately deep. Low eye socle present, separated from librigenal field by wide, shallow eye socle furrow. Genal spine blade-like, approximately the same length as the librigenal field. Pygidium up to 10 mm long (sag.), subtrapezoidal in outline excluding spines, moderately convex, sagittal length:width ratio of 47% to 54% (mean 50%; n=4) excluding spines. Anterior margin slightly curved, with the articulating half-ring being slightly convex. Axis prominent, moderately narrow (tr.), moderately tapered posteriorly, width:length ratio of 70%, occupying about 85% of sagittal length of pygidium. Articulating half-ring incompletely preserved, appears to have been short (sag.). Four well defined axial rings present, separated by deep, wide (sag., exsag.) inter-ring furrows; a faint fifth axial ring present in some specimens, separated from the terminal piece by a poorly developed inter-ring furrow. Terminal piece short (sag.). Axial furrow deep and wide (tr.). Pleural regions slightly convex, with four wide (exsag.), moderately deep pleural furrows. Furrows are contiguous with the lateral extremities of the axial rings; anterior furrows directed slightly backwards from the axial furrow and distally curved backwards, and becoming shorter and more backwardly directed posteriorly, terminating before reaching margin. Pleural ribs strongly convex. Faint, shallow, narrow (exsag.) interpleural furrows on first and second pleural ribs, extending the entire length of the rib. Border of moderate width (sag., exsag.), defined by change in convexity from the pleural region; with seven pairs of spines, first and fifth pair are considerably longer and proximally wider (tr.). Anterior first to fourth pair of spines extending posterolaterally and become progressively more backwards pointing towards the tips. Posterior sixth and seventh spine pairs directed straight back. Prosopon consists of granules of various sizes. Glabella, palpebral areas and postocular fields of fixigena as well as the posterolateral projections are densely covered in small granules with medium-sized granules randomly and equidistantly dispersed in-between. Occipital ring densely covered in small granules. Librigenal field densely covered in small and medium-sized pustules with a faint anastomosing network of genal caeca also discernable, librigenal border and spine densely covered with small granules. Pygidial axis, ribs and spines densely covered with small granules. Medium-size pustules interspersed on the axial rings and pleural ribs. Rostral plate and thorax unknown. Discussion. This taxon was originally reported as ���Damesellinae, fragments��� from Ross River Gorge at locality NT187 by ��pik (1967, appendix 2, p. 16). The specimens from the GOY section and locality 87-008 are remarkably similar, although librigenae from the former site exhibit a slightly shorter genal spine. This minor difference is either ontogenetic (the 87-008 specimens are slightly larger) or taphonomic (GOY specimens are preserved in limestone rather than a coarse sandstone). The GOY specimens also exhibit minor variation in the degree of glabellar taper during ontogeny. The lateral glabellar margins of smaller holaspid specimens converge anteriorly at approximately 20�� (Fig. 10D, H and I), whilst larger specimens (Fig. 10A, B and E) have slightly less convergence at approximately 12��. The Goyder Formation specimens are considered conspecific with Blackwelderia repanda ��pik, 1967 from the Georgina Basin. The specimens share a short (sag.) upturned anterior border, a relatively short (sag.) anterior border furrow, a slightly tapered glabella, narrow (tr.) S1 and S2 furrows, faint eye ridges, a pygidium with the first and fifth pair of spines longer (exsag.) and wider (tr.) than other spine pairs, as well as a granulose and pustulose prosopon. The Goyder Formation specimens are also similar to material identified as Blackwelderia sp. cf. B. repanda by both Wang et al. (1989) and Shergold et al. (2007) from the Mindyallan of N.S.W. and Western Australia, respectively. Although the specimens from N.S.W. are distorted, they have a short (sag.) anterior border, a slightly tapered glabella, narrow (tr.) and deep S1 and S2 furrows, faint or absent eye ridges, and a pygidium with long and wide first and fifth spine pairs (Wang et al. 1989, fig. 4R���T, 5A���I). Likewise, the specimens from Western Australia, although poorly preserved in coarse sandstone, exhibit these same features (Shergold et al. 2007, fig. 11A���F). The specimens from Western Australia differ in having a slightly more tapered glabella with a rounder anterior, and fainter pleural furrows on the pygidium. However, this falls within the range of intraspecific variation seen in other members of the genus. The synonymy of the Western Australian material is queried only because of the incomplete and limited material illustrated by Shergold et al. (2007). Blackwelderia repanda can be distinguished from other species attributed to this genus by its shorter (sag.) anterior cranidial border and anterior border furrow, the pygidial axis consisting of four (or possibly five) axial rings, faint interpleural furrows on the first and second pleural ribs, seven pygidial spines, with the first and fifth being longer (exsag.) and wider (tr.) than the others, as well as a granulose and pustulose prosopon. Blackwelderia repanda is most comparable to B. gibberina ��pik, 1967, from the Georgina Limestone, which has similar cranidial and pygidial features (cf. ��pik 1967, pl. 48, figs 1���3), but differs from B. repanda only in having the first pygidial spines slightly wider and longer and the fifth spine pair being narrower and shorter. ��pik (1967) also suggested that B. gibberina differed in having an almost transverse anterior cranidial border and pygidium without interpleural furrows. Occurrence. GOY section horizons 73.2, 83.9, 132.7 and 140.7 m (Fig. 3). Specimens also recovered from 87- 0 0 8 and GOYWEST. Distribution. Goyder Formation, Amadeus Basin, Northern Territory; O���Hara Shale, Georgina Basin, Northern Territory and Queensland; Boshy Formation, Koonenberry Belt, New South Wales. Possibly the Skewthorpe Formation, Bonaparte Basin, Western Australia. All occurrences are Cambrian Series 3, Guzhangian (Mindyallan) in age., Published as part of Smith, Patrick M., Paterson, John R. & Brock, Glenn A., 2018, Trilobites and agnostids from the Goyder Formation (Cambrian Series 3, Guzhangian; Mindyallan), Amadeus Basin, central Australia, pp. 1-67 in Zootaxa 4396 (1) on pages 22-26, DOI: 10.11646/zootaxa.4396.1.1, http://zenodo.org/record/1202723, {"references":["Wang, Q., Mills, K. J., Webby, B. D. & Shergold, J. H. (1989) Upper Cambrian (Mindyallan) trilobites and stratigraphy of the Kayrunnera Group, western New South Wales. BMR Journal of Australian Geology & Geophysics, 11, 107 - 118.","Shergold, J. H., Laurie, J. R. & Shergold, J. E. (2007) Cambrian and Early Ordovician trilobite taxonomy and biostratigraphy, Bonaparte Basin, Western Australia. Memoirs of the Association of Australasian Palaeontologists, 34, 17 - 86."]}

A new assemblage containing twenty-two species of trilobites and agnostids is described from the Goyder Formation (Cambrian Series 3) in the Ross River Syncline and Gardiner Ranges of the Amadeus Basin, Northern Territory, central Australia. New trilobite taxa described include the genus, Trephina gen. nov., and four new species Adelogonus prichardi sp. nov., Hebeia stewarti sp. nov., Liostracina joyceae sp. nov., and Trephina ranfordi sp. nov. Two agnostid taxa previously known only from Antarctica, Ammagnostus antarcticus Bentley, Jago & Cooper, 2009 and Hadragnostus helixensis Jago & Cooper, 2005, are also documented. Of the two agnostid species, the latter is the most age diagnostic, previously reported from the Cambrian Series 3 (Guzhangian; late Mindyallan; Glyptagnostus stolidotus Zone) Spurs Formation in Northern Victoria Land. This age for the Goyder Formation assemblage is supported by the co-occurrence of the trilobites Biaverta reineri Öpik, 1967, Blackwelderia repanda Öpik, 1967, Henadoparia integra Öpik, 1967, Monkaspis cf. travesi (Öpik, 1967), Nomadinis pristinus Öpik, 1967, Paraacidaspis? priscilla (Öpik, 1967), and Polycyrtaspis cf. flexuosa Öpik, 1967, also known from the late Mindyallan (G. stolidotus Zone) successions of the neighbouring Georgina Basin (Northern Territory and Queensland). The generic assemblage of the Goyder Formation is also similar to those from the Guzhangian (Mindyallan) of other parts of Australia (New South Wales, South Australia, and Western Australia), in addition to East Antarctica and North and South China.

A diverse fauna of phacopid trilobites is described from the Late Devonian (middle Frasnian to early Famennian) of the northern Canning Basin, Western Australia. One new genus and four species in two genera are described from zones 11, 13a and 13b of the middle and late Frasnian: Trimerocephaloides sinevisus gen. nov. and sp. nov., T. ? linguiformis sp. nov., Acuticryphops acuticeps (Kayser, 1889) and A. klapperi sp. nov. Late Frasnian phacopines are either blind, as shown for the first time in Trimerocephaloides sinevisus, or show trends to decreasing eye size up to the Frasnian-Famennian 'Kellwasser' mass extinction event. This evolutionary trend in Acuticryphops is demonstrated to have been global at this time. One new genus and six species of early Famennian phacopids are described, from the Upper triangularis, crepida and rhomboidea zones: Houseops gen. nov. with the new taxa H. canningensis sp. nov., H. beckeri sp. nov. and H. sp. A, Babinops planiventer Feist & Becker, 1997, B. minor sp. nov., Trimerocephalus tardispinosus Feist & Becker, 1997 and T. mimbi sp. nov. In contrast to European sections where exclusively blind phacopids are known in earliest Famennian sites, initial recovery following the mass extinction event in Canning peri-reefal environments is characterized by oculated forms. These trilobites must have evolved from conservative ancestors with normal eyes that had succeeded in surviving the Kellwasser biocrises in reef-related shallow water niches. Thus the origin of post-event phacopids from shallow water environments is demonstrated for the first time. Descendant lineages show increasing eye size, increased cephalic vaulting and effacement during the early Famennian. Of the five orders of trilobites that are present during the Frasnian Stage at the beginning of the Late Devonian, only two, the Proetida and the Phacopida, survived into the Famennian. The presence of a conformable sequence of trilobite-bearing fore-reef limestones, the Virgin Hills Formation, that form part of the Late Devonian reef system in the northern part of the Canning Basin in Western Australia, allows the patterns of evolution and extinction of the late Frasnian and early Famennian trilobites to be assessed. In these deposits the three orders that became extinct during the Frasnian-Famennian biocrises were the Corynexochida (McNamara & Feist, 2006), the Lichida (Feist & McNamara, 2007) and the Harpetida (McNamara, Feist & Ebach, in press). Here we focus on one of the groups that survived this event, the Phacopida. Although, with a single exception, they are rare elements of the trilobite fauna in the Canning Basin, the phacopids are generically the most diverse of the

Hoplolichoides PHLEGER, 1936 and Autoloxolichas PHLEGER, 1936 are revised based on redescription of their type species, H. conicotuberculatus (NIESZKOWSKI, 1859) and A. sanctamathiae (SCHMIDT, 1885) respectively. Hoplolichoides is considered to be most closely related to Hoplolichas DAMES, 1877 , and both are included in a revised Homolichinae. Autoloxolichas is restricted to its type species, and other species previously assigned to the genus are placed in Allolichas KRUEGER, 1992 , the concept of which is expanded. Autoloxolichas and Allolichas are included together with three other genera and subgenera in the Subfamily Platylichinae, previously considered to be a junior synonym of Homolichinae. The hypostomal morphology previously regarded as important in uniting homolichine and platylichine genera is now regarded as primitive for the Lichidae. Metopolichas GURICH, 1901 , previously included tentatively in the Homolichinae on the basis of its hypostomal morphology, is reassigned tentatively to the Lichinae. The trochurine ‘Acanthopyge’ erbeni MEISCHNER, 1965 , from the Givetian of Germany, is assigned to Akantharges PHLEGER, 1936 , permitting clarification of the pygidial morphology of the genus. Akantharges and Ceratarges GURICH, 1901 are unique amongst lichids in having a curved, transverse ridge on the posterolateral cranidial lobe, suggesting that these genera may have been derived from a common ancestor.

Trilobites of the family Lichidae are relatively poorly diversified within the Eifelian mixed siliciclastic-carbonate succession of the southern margin of the Dinant Synclinorium (Belgium). Until now, they were only represented by species belonging to the genera Ceratarges and Eifliarges. The recent discovery of a well-preserved specimen within the Eifelian-aged Jemelle Formation in the Couvin area led us to propose the first detailed description of a representative of the genus Ohleum (O. magreani sp. nov.) in the Ardennes

Up to four discrete protaspid larval stages are described for calymenid trilobites of Ordovician to Devonian age. The earliest growth stages are nonadult-like planktonic protaspides; later protaspides are adult-like and benthonic. In contrast, the related homalonotid trilobites apparently lack planktonic protaspides, but have up to two large benthonic protaspid stages that are similar in form to calymenid benthonic protaspides. These differences in life history patterns between these families are reflected in their paleobiogeographic distributions. Calymenids werre widely dispersed from Ordovician to Devonian times, both being common in warm, low latitude provinces (particularly from the Late Ordovician onwards) and well represented in cooler, higher latitude regions. The paleogeographic distribution of the homalonotids during the Ordovician (Arenig to the Ashgill) was concentrated in high paleolatitudes, with only a few forms occurring at low paleolatitudes (often in deeper, cooler environments?). Both families survived the Ordovician–Silurian mass extinction, with the calymenids again being widely dispersed but the homalonotids being best represented in the cool-water Malvinokaffric Province and in other regions where they are largely restricted to clastic facies.So few complete growth series of calymenine trilobites are known that it is unlikely that the ontogenies of taxa that form parts of ancestor–descendant clades can be identified. However, some evidence for heterochronic, particularly paedomorphic (neotenic), evolution is suggested for larval stages of members of both the Calymenidae and the Homalonotidae. Such possible neotenic evolution leading to very large planktonic larval stages of calymenid trilobites during the Devonian could have enhanced dispersal during a period of widespread warm and equable climates. Comparisons of homalonotid protaspides with equivalent stages of calymenids support the close relationship of these families within the Calymenina. A data matrix based upon characters of protaspides of two calymenine trilobites (Flexicalymene Shirley, 1936, and Brongniartella Reed, 1918) and eight other trilobites, belonging to the Phacopina (Calyptaulax), Cheirurina (Physemataspis and Hyrokybe), Proetida (Scharyia), Lichida (Acanthopyge), Odontopleurida (Diacanthaspis), Corynexochida (Bathyuriscus), and Ptychopariida (Crassifimbra) was subjected to cladistic analysis using the parsimony program “Hennig 86.” The shortest length cladogram produced is consistent with the inclusion of the Homalonotidae in the Calymenina, and inclusion of the Calymenina in the order Phacopida. “Cheirurina” is the paraphyletic “stem group” of Phacopina. The hypothesis that Lonchocephalidae is most closely related to part of post-Cambrian Phacopida is poorly supported by protaspid characters.

The Lichida (informal lichide) comprises two families: the Lichidae (informal lichid) and Lichakephalidae (= Eoacidaspididae). A new interpretation of lichide glabellar morphology is given, based on ontogenetic data and comparative morphology of holaspides. No occipital lobe is developed but, in front of the occipital ring, L1 is divided into subsidiary lobes L1a and L1b. The large (bullar) lobe typically lying anterior to L1b originates from L2 fairly early in ontogeny and later expands forwards, apparently incorporating more anterior parts of the glabella as it does so. L1a, L1b and the bullar lobes may be variously fused with each other or with the fixigena. The Lichakephalidae certainly includes 4 genera, 2 further genera (1 new) being: included there with reservation, whereas 43 genera and subgenera (5 new) are recognized within the five subfamilies of the Lichidae. New diagnoses are given for all these taxa with a summary of their geographical and stratigraphical distribution and lists of the species included in each genus. The phylogeny of the Lichida is discussed and cladograms summarize the relationships of genera within each subfamily. The Lichida may be related to the Odontopleurida and may also have more distant affinities with the Scutelluina.

Twenty-seven species assigned to 20 genera of trilobites are described from Feilaishi in Guizhou Province, the type section of the Shihtzupu Formation in S W China. They occur in association with a sparse graptolite fauna including Glyptograptus teretiusculus. Eleven taxa are recorded here for the first time. Much new morphological information is provided regarding previously known species and 3 lectotypes are selected. The trilobites are largely endemic and indicate a quiet and comparatively shallow water environment

A silicified trilobite fauna is described from an un-named Early Devonian (late Zlichovian-early Dalejan) limestone at Mudgee, N.S.W. The fauna includes eleven taxa as follows: Proetus sp., Cornuproetus ? sp., Astycoryphe sp., Cyphaspis sp., Harpidae gen. et sp. indet., Phacops (Phacops) sp., Crotalocephalus struszi sp.nov., Acanthopyge (Lobopyge) campbelli sp.nov., Terranovia? sp.nov., Dudleyaspis sp. cf. D. campbelli (Chatterton 1971) and Radiaspis bispinosa? (Chatterton 1971). Terranovia has not been previously described from Australia.