Late Ordovician and Silurian lichid trilobites from northwestern Canada: Hemiarges, Borealarges, and Richterarges

2007 ◽  
Vol 81 (6) ◽  
pp. 1348-1364 ◽  
Author(s):  
Margaret J. Campbell ◽  
Brian D. E. Chatterton

Four new species of Borealarges, B. fritillus, B. patulus, B. renodis, and B. variabilis, and one new species of Richterarges, R. facetus, are described and one unnamed species, Borealarges sp., discussed. All are from the Wenlock strata of Avalanche Lake sections in the Mackenzie Mountains, Northwest Territories. Borealarges tuckerae Adrain, 1994, the only species reported from both the Arctic and the Mackenzie Mountains, is discussed. Hemiarges avalanchensis n. sp., an Ashgill species from Avalanche Lake section AV 4B just below the Ordovician-Silurian boundary, is described. A phylogenetic analysis based on 14 species of Borealarges, three of Richterarges, and two of Hemiarges, demonstrates that the former two genera are three separate and distinct taxa. Borealarges, a genus that includes some species formerly assigned to Richterarges or Hemiarges, is monophyletic, contains a well-supported internal clade of species, and is not separated into senso stricto and senso lato groupings.

Zootaxa ◽  
2011 ◽  
Vol 2918 (1) ◽  
pp. 15 ◽  
Author(s):  
I. WESLEY GAPP ◽  
BRUCE S. LIEBERMAN ◽  
MICHAEL C. POPE ◽  
KELLY A. DILLIARD

The Early Cambrian olenelline trilobites are a diverse clade and have been the subject of several phylogenetic analyses. Here, three new species of Bradyfallotaspis Fritz, 1972 (B. coriae, B. nicolascagei, and B. sekwiensis) and one new species of Nevadia Walcott, 1910 (N. saupeae) are described from the Sekwi Formation of the Mackenzie Mountains, Northwest Territories, Canada. In addition, new specimens potentially referable to Nevadia ovalis McMenamin, 1987 were recovered that may expand that species’ geographic range, which was thought to be restricted to Sonora, Mexico. The results of a phylogenetic analysis incorporating several olenelline taxa, including Judomia absita Fritz, 1973 from the Sekwi Formation, are also presented herein. This species has been assigned to various olenelline genera, including Judomia Lermontova, 1951 and Paranevadella Palmer & Repina, 1993. Phylogenetic analysis suggests this species is closely related to Judomia tera Lazarenko, 1960 from Siberia. This phylogenetic relationship provides further support for the hypothesis that a close biogeographic relationship existed between Laurentia and Siberia during the Cambrian.


1995 ◽  
Vol 32 (6) ◽  
pp. 806-827 ◽  
Author(s):  
Michael W. Caldwell ◽  
Brian D. E. Chatterton

The new genus Avalanchia and the new species Avalanchia pterocarina, Cassowarioides anisomorpha, Cassowarioides polgari, Nehedia bergeraci, Nehedia restricta, and Nehedia tricarina are proposed from exceptionally preserved silicified faunas. Two new but unnamed rostroconch species are also described. These conocardioid rostroconchs were collected from Silurian deposits (late Llandovery to early Ludlow) near Avalanche Lake in the Mackenzie Mountains, Northwest Territories, Canada, and, when added to global rostroconch faunal lists, indicate a previously unrecognized diversity of Silurian conocardioid rostroconchs. The morphology of conocardioid rostroconchs is discussed, and a glossary of terms presented. Sexual dimorphism is recognized in species of Cassowarioides. Phylogenetic analysis of hippocardiids and bransoniids supports the monophyly of several genera. The hippocardiid genus Bigalea Pojeta and Runnegar, 1976, is recognized as paraphyletic and three species are assigned to a new genus, Redstonia. Preliminary analysis of bransoniids and hippocardiids for familial relationships, using data sets from the within-family analyses, indicates that the Bransoniidae is polyphyletic. The generic complex Mulceodens, considered to be derived bransoniid, is consistently reconstructed within a clade of derived hippocardiids.


1977 ◽  
Vol 55 (1) ◽  
pp. 52-60 ◽  
Author(s):  
D. G. Lee ◽  
W. G. E. Caldwell

A new species of dasycladacean alga is present in the upper Thumb Mountain and in the overlying Irene Bay Formations of the Cornwallis Group on Cornwallis Island, Northwest Territories. The alga is associated with the 'Arctic Ordovician' fauna, which is of considerable biogeographical and biostratigraphical importance. This fauna is believed to be of early Late Ordovician (Caradocian) age.The new alga is a member of the cyclocrinitid tribe and clearly is to be referred to the genus Cyclocrinites. It is distinguished from all other cyclocrinitid species by the exceptionally small size, the unusual bilobate form, and the mode of calcification of its thallus. It is believed to have lived in tropical waters which were quiet and shallow, to have been anchored to the seabed by means of rhizoids. and to have grown only in areas in which fine-grained carbonate sediment was accumulating.


Zootaxa ◽  
2010 ◽  
Vol 2516 (1) ◽  
pp. 1 ◽  
Author(s):  
ANTOINE MANTILLERI

The genera Hoplopisthius and Carcinopisthius are reviewed. All the species are redescribed and illustrated and an updated identification key and distributional maps are provided. One new species from New Guinea is described (Hoplopisthius maximus n. sp.) and two new synonymies are proposed: Hoplopisthius celebensis Kolbe, 1892 = H. trichemerus Senna, 1892, n. syn. and Carcinopisthius lamingtoni Damoiseau, 1987 = C. forcipitiger Damoiseau, 1987, n. syn. Phylogenetic analysis using PAUP (maximum parsimony) was performed using 25 morphological characters of adults. This analysis shows the group Hoplopisthius + Carcinopisthius is monophyletic, but Carcinopisthius alone is paraphyletic. Nomenclatural changes at the generic level are made to reconcile nomenclature and phylogeny: Hoplopisthius is preserved; Carcinopisthius is downgraded to the rank of subgenus for the two oriental species H. oberthueri and H. fruhstorferi; and Pseudotaphroderes is resurrected as a third subgenus and includes all New-Guinean and Australian species.


1995 ◽  
Vol 69 (2) ◽  
pp. 307-326 ◽  
Author(s):  
Jonathan M. Adrain ◽  
Brian D. E. Chatterton

Maurotarion Alberti, 1969, is a diverse otarionine clade that can be readily distinguished from Harpidella M'Coy, 1849. Both genera appear in the Upper Ordovician and range until the Middle Devonian. A new diagnosis for each taxon is given. New species of the genera from the Ordovician and Silurian of the central Mackenzie Mountains, Northwest Territories, Canada, include Harpidella kurrii (Ashgill), H. tikkaneni (Llandovery), H. greggi (Wenlock), and Maurotarion messieri (Llandovery). Harpidella megalops (M'Coy, 1846), H. triloba (Hu, 1975), H. spinafrons (Williams in Cooper and Williams, 1935), Maurotarion struszi (Chatterton, 1971), and M. instita (Whittington and Campbell, 1967) are revised.


ZooKeys ◽  
2020 ◽  
Vol 985 ◽  
pp. 71-126
Author(s):  
Jose I. Martinez

The endemic Neotropical genus Gaujonia Dognin is revised. Morphological characters and a phylogenetic analysis demonstrate paraphyletic relationships among the species. Four different groups are interpreted to represent four different genera. The G. arbosi group is the only remaining clade in the genus Gaujonia, and the other groups have been arranged into three new genera: Milleranagen. nov., Oculicattusgen. nov., and Cicadoformagen. nov. Additionally, two other genera Cicadomorphusgen. nov., and Gaujopteragen. nov. were found using morphological and molecular analyses based on some specimens that were misidentified as Gaujonia spp. A total of five new genera, three new combinations (Cicadoforma vau-nigrum Hampson, comb. nov., Oculicattus renifera Hampson, comb. nov., and Millerana arbosioides Dognin, comb. nov.) and 21 new species (Cicadoforma ocelotussp. nov., Cicadomorphus chicharrasp. nov., Cicadomorphus chuyasp. nov., Cicadomorphus falkasiskasp. nov., Cicadomorphus lilianaesp. nov., Gaujonia bichusp. nov., Gaujonia chiqyaqsp. nov., Gaujonia kanakusikasp. nov., Gaujonia sourakovisp. nov., Gaujoptera amsasp. nov., Millerana austinisp. nov., Millerana cajassp. nov., Millerana cundinamarquensissp. nov., Millerana matthewsaesp. nov., Millerana tigrinasp. nov., Oculicattus bolivianasp. nov., Oculicattus brehmisp. nov., Oculicattus incasp. nov., Oculicattus raizaesp. nov., Oculicattus schmidtisp. nov., and Oculicattus uturunkusp. nov.) are established.


1973 ◽  
Vol 10 (9) ◽  
pp. 1460-1464 ◽  
Author(s):  
A. C. Lenz

The genus Nadiastrophia previously recorded only from Australia and China, is described from the Headless Formation of the Mackenzie Mountains. This discovery further emphasizes the early Middle Devonian faunal affinities between the Cordilleran and southeastern Pacific regions. The Mackenzie Mountains Nadiastrophia is assigned to a new species, N. mackenziensis.


1997 ◽  
Vol 54 (2) ◽  
pp. 125-170 ◽  
Author(s):  
A. L. Schutte

Cyclopiais a papilionaceous genus endemic to the Western and Eastern Cape Provinces of South Africa. The 23 species recognized within the genus have rather subtle differences, but characters of the leaves, bracts and calyces, as well as the adaptations to survive recurrent fires, are useful to distinguish between the species. Variations in morphological, cytological and chemical characters are discussed. A phylogenetic analysis of 21 characters by means of cladistic methodology produced a cladogram with five distinct groups. These are described as sections in the taxonomic part of the paper. One new species,Cyclopia alopecuroidesA.L. Schutte, is described. The nomenclature, synonymy and typification of the taxa are presented, as well as full descriptions, illustrations and distribution maps.


1994 ◽  
Vol 68 (2) ◽  
pp. 305-323 ◽  
Author(s):  
J. M. Adrain ◽  
B. D. E. Chatterton

The genus Otarion Zenker, 1833, first appears in the Wenlock simultaneously with Cyphaspis Burmeister, 1843, as the oldest known species of each occur together in the southern Mackenzie Mountains of the Canadian Northwest Territories. The genera are unambiguous sister groups, a relationship supported most compellingly by a uniquely derived and distinctive pattern of juvenile cephalic spines, shared also with the Carboniferous genus Namuropyge Richter and Richter, 1939. This sister group relationship permits the development of a robust and stratigraphically correlated hypothesis of relationship among the adequately known species of Otarion, Otarion, Cyphaspis, and Namuropyge constitute the tribe Otarionini. The Mississippian genus Dixiphopyge Brezinski, 1988, may also belong to Otarionini. Namuropyge is a paedomorph, likely derived from a Degree Six or Seven meraspid of an older species of uncertain position in the Otarion–Cyphaspis clade.Three Wenlock species of Otarion occur in stratigraphic succession in a single section in the Mackenzie Mountains. Analysis of morphological change with time, and of sequential ontogenies, suggests that the Silurian history of the genus was dominated by incidents of peramorphosis.New species are Otarion huddyi, O. beukeboomi, and O. coppinsensis. Otarion brauni Perry and Chatterton, 1979, is revised.


Phytotaxa ◽  
2014 ◽  
Vol 176 (1) ◽  
pp. 174 ◽  
Author(s):  
HUI YANG ◽  
HIRAN A. ARIYAWANSA ◽  
HAI-XIA WU ◽  
KEVIN D. HYDE

Leptoxyphium is a relatively poorly known genus of sooty moulds in Capnodiaceae (Dothideomycetes). This paper introduces one new species of Leptoxyphium, L. glochidion and the first record of L. kurandae for China. L. glochidion is introduced as a new species based on morphology and molecular data and is compared with related taxa. Descriptions, illustrations and notes are provided for the two species, which are analyzed by ITS, LSU and SSU sequence data. The phylogenetic analysis shows that the two species cluster in Leptoxyphium (Capnodiaceae). L. glochidion separates from other species of the genus, while L. kurandae clustered with the type strain


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