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Home , Bumastus, Calymene, Calymenidae

A fauna dominated by from Kap Tyson, Hall Land, western North

Philip D. Lane and Derek J. Siveter

The Silurian described here are referred to 5 genera and 5 -level taxa of which Calymene iladon is new. The composition of the fauna is unusual for North Greenland in that it is overwhelmingly dominated by specimens of Calymene. Other elements of the fauna are known from other areas of North Greenland, and at least closely related forms of one of them have cosmopolitan distributions.

P. D. Lane, Department of Geology, University of Kee!e, Kee!e, Staffordshire, ST5 5BG, u.K. D. J. Siveter, University Museum, Parks Rd., Oxford, OXI3PW, u.K.

The trilobites described in this paper were collected Formation, Wenlock Series, Silurian; West Midlands, in western North Greenland by M. Sønderholm during U.K. 1985, from the flanks of a carbonate mound on the tip of Kap Tyson (Fig. l), within the Offley Island Formation (Hurst, 1980); they are therefore of late Llandovery Sp. Fig.2e age. A summary of the geology of Hall Land, including the biostratigraphic setting, was given by Dawes & Peel Figured material. MGUH 19510 (fragmentary crani­ (1984). dium from GGU 301925). In described trilobite faunas from the Silurian plat­ form carbonates of North Greenland (Lane, 1972, 1979, Diseussion. A single fragmentary cranidium is best re­ 1984, 1988; Lane & Peel, 1980; Lane et al., 1980; Lane ferred to Bumastus. Although it displays a sculpture of & Owens, 1982), and in collections scanned but not yet densely-spaced small pits like that of material from the described (P. D. Lane, unpublished reports to Grøn­ Wenlock of Kronprins Christian Land, eastern North lands Geologiske Undersøgelse, 1980, 1986) calymenid Greenland referred to 'goldillaenid gen. et sp. indet. 2' trilobites are very rare and always disarticulated. In the by Lane (1972, p. 347, pI. 62, fig. 14) it displays the present collections of some 90 specimens, Calymene characteristic broadly oval, exsagittally elongate Ig gla­ iladon sp. nov. accounts for all but seven specimens, bellar muscle impression placed at about 150% of its and its remains are substantially articulated. own length from the posterior cranidial border shown by species of the (Lane & Thomas, 1978, pI. 1, fig. 5). Systematic descriptions All specimens are from GGU sample 301925. Type Genus Ekwanoscutellum Pfibyl & and figured specimens (MGUH prefix) are deposited in Vanek, 1971 the Geological Museum, Copenhagen. Type species. Bronteus ekwanensis Whiteaves, 1904 Vogdes, 1890 from the late Llandovery of Ontario, . (emend. Lane & Thomas, 1983) ?Ekwanoscutellum Sp. Genus Bumastus Murchison, 1839 Fig.2d Type species. Bumastus Barriensis Murchison, 1839 Figured material. MGUH 19511 (fragmentary crani­ from the Barr Member of the Coalbrookdale dium from GGU 301925).

Rapp. Grønlilnds geol. Unders. 150, 5-14 (1991) © GGU, Capenhagen, 1991 6 60' 55 I I

KA.P BRYANT

NYEBOE LAND

'.--; ~: " <, ';\j(, ,-..l ',', "/.- (,'-'y' ,y.~._,

Fig. I. Western North GreenlHnd showing thc col1cction locality for GGU 301925.

DisfLlssion. A solitary cranidial fragmem shows a com­ DiscussiOfI. Thc specimens agree well with lhe material plete anterior border fUrTo\\' which thus exdudcs assi g­ figure<1 by Lane (1984. pI. 1, figs 12.14--16). from strata nation to 0POll, Meroperix or Kosovopeltis. The ante· of possibIe Wenlock age from Kayscr Bjerg, Hall Land. rior border. however, has some resemblance to lhat af In his diseussion whell establishing the species Lane Ekwonoscmellum (scc E. ekwonensis figured by Nor­ noted ilS great similarity. especi;;lIly in the morphology ford 1981. pI. 2. figs 2. 4) in that it beeomes higher and af the cranidium and the sIit-likc gJabellar furrows, to arehes upwards sagiually_ \Vithout confidence, there· K. Ichemychel'fle Snajdr. 1960 from an undefined Silur­ fore. we assign il to that genus. ian horizon on the River Vagran. Urals, U.S.S.R. Very similar, if not conspecific, taxa form a spccies-group of Genus Kosovopeltis Snajdr, 1958 Silurian age also in other parts of , south-east and . Type species. KOJOVOpellis svobodai Snajdr, 1958, from From the type L1andovery area. \VaJes, a single smal! the Ludlow of Czcchoslovakia. complete specimen (which is rcfcrabJe to K. cf. K. alIaarii; National Museum no. 443732) is Kosovopeltis allaarti Lane, 1984 known from the Rhydings Formation (MoflograplUs Figs 2a-c sedgwickii Biozone; Aeronian : mid LIandovery). Kosovopeitis sp. afr. K. attaarl; of Siveter (1989. p. 114) Figuret! marerial. MGUH 195J2 ( with 8 anie­ is from Ihe lale Wenlock or carly Ludlow uf south-west ulated thoraeic segments); MGUH 19513-4 (pygidia); , and another dose form from the L1andovery of all frol11 GGU 301925. the Oslo region, , has been examined by onc of Ihe aUlhors (P. D. L; unregistcred specimcn in Palaeon­ lologisk Museum, Oslo). Fig. 2. a-c. Ko.l"Ol'o{JeJris allaarti Lane, 1984, MGUH 19512-4; 2 pygidia and pygidium with eight articulated thoracic segments, dors,11 views. x 2, x l and x 4 respectively. d. ?EkwatlOSClllellwll sp., MGUH 19511; fragmcntary cranidillf1l, dorsal view. x 3. c. BWllastus sp., MGUH 19510; fragmcnlary cranidillm. dorsal vie\\.'. x 3. f, g. Meilanillae/JlJs sp., MGUH 19515-6; partial thoraces and pygidia, dorsal views. x 4.

Tn Honshu and Shikoku. Japan, what is very probably Genus Meitanillaenus Chang, 1974 a single species af K050VOpe!tis close to if not conspcc~ Faiffeana Chatterton and Luctvigsen, 1976 ific with al/aani has been describcd under seven species Opsypharus Howells, 1982 group designa(ions - Micro5cutellum primigenium and Microscuteifum sp. nov. (bOlh Kobayashi & Hamada. Type species. Meilanif/aenus binodosus Chang, '1974, 1974); Japonoscuwlfum japonicwn puteatum, Japano­ from the L1andovery of Guizhou Province, People's scurellunl japonicum. faricepha/um and 'Scutelloid gen. Republic of . et sp. indet.' (all Kobayashi & Hamada, 1986); and Kosovopeilis IIidensis IIidensis and KOSOl-'Opeilis hidensis Meitanillaenus Sp. slrimum (both Kobayashi & Hamada, 1987). Kosovo­ Figs 2f, g peffis ienkinsi (Etheridge & Mitchell, 1890; see Chatter­ ton & Campbell (1980, p. 103, pI. 12, ligs 1-9) who Figllred malaia!. MGUH 19515-6 (pygidia, with 6 and commented on its similarity to and possibIe conspecific­ l thoracic segments attaclled respcctivdy from GG U ily with K. lchernychevae) from the Luctlow af New 301925). South , Australia, Kosovopeiris guangycuwensis Zhou & Chen, 1975 from the Telychian af North Si­ Discu.uiofl. The anI y ether two non-calymenid trilobite chuan, People's Republic af China and probably 'P/ani­ fragments from the fauna may be referred to Meitafl­ scureffum' niuchangensis Chang (1974, p. 175, pI. 80. iffaenus. Thc present specimens 1ack the clear paired fig. I) from tlle Silurian of south-wcst China are also at muscle irnpressions and sagittal carina. morpholagical least c1osel)' related forms. features which can vary in cxpression within a population (Lane & Thomas, 1978, p. 16), compared to the pygidia described and figured as Upsypharus sp. by Lane (1984, p. 55, pI. -I, figs 5-8), also from possiblc Wenlock strata 8 of Hall Land. The paired muscle impressions are pre­ V-shaped mediaIly, becoming much deeper and gradu­ sent in the type species, but from Chang's illustration, ally narrows (exsag.) behind Ll. The latter is subquad­ the posterior outline of the pygidium is semicircular, as rate in outline and separated from central glabellar area compared to subtriangular in the Greenland material. by extremely weak, broad (tr.) posterior extension of In addition, that material shows a less well-developed SI. Within the adaxial fork of SI there is a small, holcos anterolaterally where it is much narrower ad~ distinct intermediate lobe and the anterior branch of SI jacent to the anterior border. The preservation in the runs anteriorly as a shallow depression over inner neck two sets of material is, in any case, very different. of L2 to connect with a well-incised S2. L2 is one-halt to two-thirds the size of Ll, abaxially it is papilIate in Family Milne Edwards, 1840 outline, and directed outward and slightly for~r,d, to Subfamily Calymeninae Milne Edwards, 1840 contact with a short (tr.) buttress from the fixed cheek. L3 is distinctly inflated, about one-halt the size of L2 Genus Calymene Brongniart in and runs transversely down the side of the glabella. S3 is Brongniart & Desrnarest, 1822 well marked. Some specimens have a L4 and a very weak S4. Frontal lobe is about 0.8 times as wide as the Type species. Calymene blumenbachii Brongniart in glabella across LI, moderately to well-rounded in dorsal Desmarest, 1817 (see Siveter, 1989, p. 128). outline, projects moderately in front of the fixed cheeks. In lateral profile the glabella stands well above Calymene iladon Sp. nov. height of fixed cheek, is gently to moderately dorsally Plates 1, 2 convex and falls only slightly in height from occipital furrow to frontallobe; thereafter it is much more con­ Derivation ofname. Greek 'in great abundance'. vex and descends more sharply to anterior face of front­ allobe which slopes downward and slightly backward to Holotype. MGUH 19517 (cranidium). the preglabellar furrow. Axial furrow is nal;.row and shallowest beside the occipital ring, deep and slightly Figured material. MGUH 19518-9 (cephala); MGUH crescent-shaped beside Ll, slightly deeper and wider at 19520-3 (cranidia); MGUH 19524 (free cheek); MGUH SI, and interrupted at L2 by the contact of this lobe with 19525 (hypostorne); MGUH 19526-8 (partial thoraces the buttress from the fixed cheek; from S2 to the pregla­ with articulated pygidia); MOUH 19529-30 (pygidia), bellar furrow it is deep and narrow. The preglabellar all from GGU 301925. furrow is short and of moderate depth sagittally; abax­ ially it becomes deeper. Between the anterior border Other mateTial. GGU 301925.1-25 (cranidia); GGU and the fixed cheek the border furrow is eqmllly short 301925.26-40 (free cheeks); GGU 301925.41-43 (hy­ (exsag.) and slightly shallower than the sagittal depth of postornes); GGU 301925.44-58 (partial thoraees); the preglabellar furrow. Anterior face of preglabellar GGU 301925.59-83 (pygidia). furrow rises sharply for a short distance and passes smoothly into the dorsal surface of the anterior border Diagnosis. A species of Calymene combining the folIow­ ing characters: a relatively short preglabellar area which Plate 1 is 0.1--0.14 times as longas the glabella; anterior border is a short, low, upturned rim; palpebrallobe forwardly All specimens are from GGU sample 301925, Kap Tyson, Hall positioned, mid-length centred on L3; hypostorne with Land, western North Greenland. non-differentiated to extremely weakly raised macula Calymene iladon sp. nov. situated in a sunken suboval area; pygidium with seven Figs la-d, MGUH 19517; holotype cranjdium, dorsal, frontal, or eight axial rings and five or six pleural furrows. left lateral and oblique left lateral views, x 4. 2a, b, MGUH 19526; paratype pygidium and nine thoracic segments, right Description. Cranidium is about 1.7 times as wide as it is lateral and dorsal views. x 3. 3, MGUH 19525; paratype long. Glabella is very weakly bell-shaped in outline and hypostorne, ventral stereo-pair view, x 10. 4a, b, MGUH about 0.75--0.8 times as wide as it is long. Occipital ring 19520; paratype fragmentary cranidium, left lateral and dorsal views, x 4. 5, MGUH 19529; paratype pygidium, posterior is slightly narrower (tr.) than the glabella at Ll; in view, x 4. 6, MGUH 19521; paratype cranidium, dorsal view, dorsal view it arches forward mediaIly, and is gently to x 4. 7, MGUH 19524; paratype left free cheek, plan view, x 4. moderately convex in profile (sag.); abaxially it is very 8a-d, MGUH 19518; paratype cephalon, left lateral, oblique weakly inflated, and about 0.7 times as long (exsag.) as anterior, anteroventral and dorsal views, x 4. 9, MGUH it is sagittally. Occipital furrow is moderately deep and 19522; paratype cranidium, dorsal view, x 4. Plate I 9 10 which turns sharply over to descend in a short, slightly rior wing moderately large, with a dorsally directed pit. forwardly-projecting and moderately strongly convex Lateral border is narrow and tightly convex (tr.); lateral arc to rostral suture. Anterior border is relatively low border furrow is best marked anteriorly. Posterior mar­ and reaches dorsally about one-half to two-thirds up the gin is bifid, with two small to moderately large flat anterior face of the frontal glabellar lobe. Opposite spines which are delimited from the middle body by a abaxial part ofaxial furrow and innermost part of fixed well-marked posterior border furrow. Medially, post­ cheek the anterior border is longer (exsag.) than it is erior border is extremely short (sag.). Anterior lobe of sagittally; between innermost part of fixed cheek and middle bodY is about 2.5 times as long (sag.) as the anterior branch of facial suture it narrows (exsag.) posterior lobe; it bears a strongly ventrally-projecting sharply and descends steeply. median protuberance. Posterior lobe falls steeply post­ Posterior border is tightly convex (exsag.) and ex­ eriorly (sag.) to border furrow, slightly less so abaxially pands slightly in length (exsag.) between axial furrow to lateral shoulder. Macula is at most extremely weakly and fulerum; farther abaxially, it is slightly less convex differentiated, sited in a sunken suboval area; median and widens gradually to a point near genal angle where furrow is present only laterally, leading anteriorly and posterior margin and border furrow become more par­ slightly abaxially from suboval area to meet anterior allel because of the slight forward flexure of the post­ part of lateral border furrow. erior margin. Posterior border furrow is narrow, moder­ Thorax has at least 11 segments; axis is weakly to ately deep to deep and V-shaped in profile (exsag. ); it moderately arched (tr.). Axial ring is flat to gently meets posterior section of lateral border furrow on fixed convex in profile (sag.), lengthens (exsag.) slightly at cheek just before facial suture. Posterior part of fixed the axial furrow where it is weakly produced forward cheek is long and in profile (exsag.) it is flat to very and has a subrounded outer, anterior margin. Articulat­ gently dorsally convex between palpebrallobe and bor­ ing furrow is U-shaped, sagittally it is one-quarter to der furrow; abaxially it slopes steeply to facial suture. one-third the length of the axial ring and it becomes Anterior part of fixed cheek is about as wide as L2; its narrower at the axial furrow. Articulating half-ring is inner anterior corner is slightly angular and weakly slightly shorter than axial ring and gently convex (sag.). overhangs the border furrow. Palpebrallobe is about as Pleural furrow is sharply incised; it narrows gradually long as L2 and narrow (tr.); it rises moderately steeply abaxially where it runs slightly forward onto pleural from fixed cheek and its abaxial margin is slightly facet before turning backward slightly to die out. Post­ pointed at its mid-Iength which lies opposite (tr.) L3. erior pleural band is moderately to strongly convex Width of cranidium at posterior margin of palpebral (exsag.), it narrows gradually abaxially to form a lobe is 1.65-1.7 times glabellar width at L2. Posterior bounding rim to the articulating facet; anterior pleural branch of facial suture runs slightly backward for a short band is lower and shorter. Fulcrum is at a distance (tr.) distance before turning sharply backward; farther on, at from the axial furrow which varies, from the posterior a point just before lateral border furrow, it turns more to the anterior part of thorax, from about 0.15 to 0.3 adaxially onto lateral border; thereafter it runs exsagit­ times the axial width. tally before finally bending slightly outward again to Pygidium is about 1.6 times as wide as long. Axis of bisect genal angle. Anterior branch runs slightly inward seven or eight rings is about 0.45 times as wide as to border furrow, then it turns sharply inward across pygidium; it is moderately convex anteriorly and more anterior face of anterior border to meet rostral suture. Free cheek bears a narrow eye socle; main field is Plate 2 moderately convex; border furrow is U-shaped; border All specimens from GGU sample 301925, Kap Tyson, Hall is generally wide but narrows near genal angle; it is Land, western North Greenland. strongly convex adjacent to anterior branch of facial suture though less so posteriorly. Calymene iladon sp. nov. Rostral plate comprises border and doublure sectors. Figs la-e, MGUH 19519; paratype cephalon, dorsal stereo­ Border sector is about 4.9 times as wide (tr.) as long pair, right lateral, frontal, left lateral and right lateral oblique (sag.). Rostral and hypostomal sutures are broadly views. x 4. 2a-d, MGUH 19530; paratype pygidium, posterior stereo-pair, dorsal, right lateral and right lateral oblique views, arched; connective suture is slightly convex abaxially x 4. 3a-c, MGUH 19527; paratype pygidium and seven artic­ and it trends strongly inward and downward from the ulated thoracic segments, dorsal, posterior and left lateral junction of the {acial and rostral sutures. Anterior bor­ views, x 3. 4a-c, MGUH 19528; paratype pygidium and two der of hypostorne is strongly reflexed ventrally; anterior articulated thoracic segments, right lateral, dorsal and right border furrow is marked by a break in slope between lateral oblique views, x 3. 5a, b, MGUH 19523; paratype anterior border and anterior lobe of middle body. Ante- cranidium, left lateral oblique and dorsal views, x 4. Plate 2 11 12 so posteriorly where its sides descend more steeply to Silurian of these areas. There are only two other records the axial furrow. Inter-ring furrows are mostly best of Calymene from Greenland, both of which reter, to marked abaxially and shallowest medially, and the unnamed species. The Calymene sp. of Lane (1972, pI. eighth (and sometimes seventh) are isolated from the 64, figs 6, 7) from late Llandovery or early Wenlock axial furrow. Small terminal piece falls steeply to post­ stratabi: Kronprins Christian Land differs in its subpar­ axial sector. Axial furrow is well marked, weakest ante­ allel-sided, more strongly sagittally convex glabella; its riorly and becomes progressively better incised post­ shorter preglabellar area, the very short anterior border eriorly; behind postaxial sector it becomes more diffuse of which is scarcely visible in dorsal view; and its more again. Pleural region slopes strongly for a short distance posteriorly positioned palpebrallobe, the mid-Iength of to the fulcrum, thereafter very strongly to lateral margin which lies opposite the anterior part or margin of lobe where it rolls tightly under to doublure. Fulcrum very 2p. On the cranidia of the Kronprins Christian Land dose to axial furrow. First pleural furrow runs onto Calymene, which are largely internal moulds, there is in articulating facet. There are at least five well incised addition the suggestion of a very weak 5p lateral glabel­ pleural furrows which are weakest adjacent to the axial lar lobe (Lane, 1972, p. 359). furrow; they become deeper and slightly wider at mid­ The former distinctions also apply to the Calymene length before narrowing and ending dose to the lateral sp. of Norford (1981; it is not referable to margin. Interpleural furrows are relatively weak at axial - Derek J. Siveter & B. D. E. Chatterton, unpublished furrow, more abaxially very weak or absent, becoming information) from the late Llandovery or early Wenlock better defined distally. Anterior pleural band of sixth of Hudson Bay, Canada, which incidentally at least very pleura forms weakly posteriorly projecting side to post­ dosely resembles the Calymene sp. of Lane, 1972. axial sector; short, weak sixth pleural furrow is some­ Calymene sp. of Lane (1984, pI. 2, fig. 10) also from times present. Hall Land in rocks of probable Wenlock age is repre­ Sculpture on dorsal surface of cranidium and main sented by a single cranidium which is less complete than field of free cheek is of very small to large granules Lane's (1972) material, but so far as can be judged, the which are very sparse and very small on most dorsal two sets of material also represent similar if not the parts of sides of cranidial furrows. Very loosely scat­ same species. This latter cranidium can still be dis­ tered, small granules are present in the lateral border tinguished from c. iladon by having the mid-Iength of furrow; medium, rather uniformly sized, dosely distrib­ the palpebral lobe transversely opposite the anterior uted granules occur on lateral border and border sector margin of the L2. of rostral plate. Very small granules are present on The buttressing of the fixed cheek opposite the L3 in middle body and borders of hypostorne. Small to large the calymenid cranidia described as Calymene sp. by sized granules occur on all axial rings and inner pleural Perry & Chatterton (1977, pI. 4, figs 19--21) from the region where they are more loosely scattered. auter Wenlock of the Canadian Arctic, readily separates this part of pygidial pleural region, postaxial sector and material from C. iladon. af figured Canadian Silurian border roll have medium sized dosely packed graoules. calymenids, one of the most similar to C. iladon is the Granules are absent from deeper parts ofaxial, ring, single cranidium referred to C. breviceps Raymond by pleural and interpleural furrows. Ludvigsen (1979, p. 68, fig. 45, E) from the late Wen­ lock (see Berry & Boucot, 1970, p. 115) Eramosa For­ Discussion. The combination of features given in the mation of southern antario. This cranidium, however, diagnosis immediately differentiates this new Calymene does not belong to breviceps (for instance its preglabel­ species, but the very forwardly placed palpebral lobe lar area, though relatively short, is still much longer and, apparently, the nature of the maculae, are the (sag.) than that of the American taxon in which it is most important distinguishing characters. The only hy­ exceptionally short; see Whittington, 1971, pI. 83, figs postornes recovered are small or indifferently preserved 1, 2), but it does not precisely agree with C. iladon in the area of the maculae, but at most this feature either, .as its palpebral lobe does not appear to be so seems to be extremely weakly discriminated and is sited forwardly placed. in a sunken suboval area. af named Calymene species, C. frontosa Lindstr6m, Previously described Silurian calymenids from 1885, known from the late Llandovery to early Wenlock Greenland, or from northern or Arctic Canada - areas in the Baltic, Scandinavia and , shows simi­ which show trilobite faunallinks with Greenland at this larity to C. iladon in its continuously narrow cranidial time - are represented by sparse and generally poorly posterior border furrow. This is a relatively unusual preserved specimens. The calymenid described here feature in species of the genus, but many other features represents by far the most complete known from the separate C. frontosa, induding its longer preglabellar 13 area, higher anterior border and deeper preglabellar Kobayashi, T. & Hamada, T. 1987: On the Silurian trilobite furrow, and the strongly subeonieal andoverhanging faunule of Hitoegane near Fukuji in the Hida Plateau, Ja­ anterior eorner of its fixed eheek (Mannil, 1977, pI. 2, pan. Trans. Proc. pa!. Soc. Japan 147, 131-145. fig. 1). C. chica Snajdr (1982, pI. 2, fig. 1) from the Lane, P. D. 1972: New trilobites from the Silurian ofnorth-east Prfdoli of Czeehoslovakia is not toa dissimilar from C. Greenland, with a note on trilobite faunas in pure lime­ iladon, but in the Bohemian form the palpebral lobe is stones. Palaeontology 15, 336-364. Lane, P. D. 1979: Llandovery trilobites from Washington more posteriorly positioned (Siveter, 1989, p. 132, has Land, north Greenland. Bull. Grønlands geol. Unders. 131, further diseussion). 37 pp. Lane, P. D. 1984: Silurian trilobites from Hall Land and Nye­ Acknowledgements. We thank Dr John S. Peel for bringing the boe Land, western North Greenland. Rapp.Grønlands geo!. material to our attention and arranging for its loan. Dr Alan Unders. 121, 53-75. Thomas suggested improvernents to the typescript for which Lane, P. D. 1988: Silurian trilobites from Peary Land, central we are grateful. North Greenland. Rapp.Grønlands geo!. Unders. 137, 93­ 117. References Lane, P. D. & Owens, R. M. 1982: Silurian trilobites from Kap Schuchert, Washington Land, western North Greenland. Berry, W. B. N. & Boucot, A. J. 1970: Correlation of the Rapp. Grønlands geol. Unders. 107, 41-69. North American Silurian rocks. Spec. Pap. geol. Soc. Arner. Lane, P. D. & Peel, J. S. 1980: Trilobites and gastropods from 102,289 pp. Silurian carbonate mounds in Valdemar GHickstadt Land, Brongniart, A. & Desmarest, A. G. 1822: Histoire naturelle eastern North Greenland. Bull. Grønlands geol. Unders. des crustaces fossiles sous les rapports zoologiques et geolo­ 101, 54 only. giques. Savoir: Les Trilobites. Paris. 154 pp. Lane, P. D. & Thomas, A. T. 1978: Family Scutelluidae. In Chang Wen-Tang 1974: [Silurian Trilobita] 173-187, pis 80-85. Thomas, A. T., British Wenlock trilobites. Part 1. Monogr. In Nanking Institute of Geology and Palaeontology (ed.) [A palaeontogr. Soc. {London}. 56 pp., pis 1-14 (Publ. No. 552, handbook ofthe stratigraphy and palaeontology in southwest part of Vol. 132 for 1978). China]. Beijing: Science Press. Academia Sinica. [In Chi­ Lane, P. D. & Thomas, A. T. 1983: A review of the trilobite nese.] suborder Scutelluina. In Briggs, D. E. G. & Lane, P. D. Chatterton, B. D. E. & Campbell, K. S. W. 1980: Silurian (ed.) Trilobites and other early : papers in honour trilobites from near Canberra and some related forms from of Professor H. B. Whittington, FRS. Spec. Pap. Palaeont. the Yass Basin. Palaeontographica A 167, 77-119, pis 1-16. 30, 141-160. Chatterton, B. D. E. & Ludvigsen, R. 1976: Silicified Middle Lane, P. D., Dawes, P. R. & Peel, J. S. 1980: A new Silurian trilobites from the South Nahanni River area, Hemiarges (Trilobita) from North Greenland and the ques­ District of Mackenzie, Canada. Palaeontographica A 154, tion of the Polaris Harbour Formation. Rapp.Grønlands 106 pp., 22 pis. geol. Unders. 101, 45-53. Dawes, P. R. & Peel, J. S. 1984: Biostratigraphic reconnais­ Lindstrom, G. 1885: Forteckning på Gotlands siluriska crusta­ sance in the Lower Palaeozoic of western North Greenland. ceer. Ofvers K. VetenskAkad. Forh. 6, 37-100, pis 12-16. Rapp. Grønlands geol. Unders. 121, 19-51. Ludvigsen, R. 1979: of Ontario. Part 1 : The Trilobites. Desmarest, A. 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I. 1839: The Silurian System. xxxii+768 pp., in Washington Land and western Hall Land, North Green­ 37 pis. London: John Murray. land. Bull. Grønlands geol. Unders. 138, 95 pp. Norford, B. S. 1981: The trilobitefauna ofthe Silurian Attawa­ Kobayashi, T. & Hamada, T. 1974: Silurian trilobites of Japan pi~kat Formation, northern Ontario and northern Manitoba. in comparison with Asian, Pacific and other faunas. Spec. Bull. geol. Surv. Canada 327,37 pp. Pap. pal. Soc. Japan 18, 155 pp. Perry, D. G. & Chatterton, B. D. E. 1977: Silurian (Wenlock­ Kobayashi, T. & Hamada, T. 1986: The second addition to the ian) trilobites from Baillie-Hamilton Island, Canadian Arctic Silurian trilobite fauna of Yokokura-yama, Shikoku, Japan. Archipelago. Can. J. Earth Sci. 14, 285-317. Trans. Proc. pal. Soc. Japan 143, 447--462. Perry, D. G. & Chatterton, B. D. E. 1979: Wenlock trilobites and brachiopods from the Mackenzie Mountains, north­ western Canada. Palaeontology 22, 569-607. 14

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