Upper Llandovery and Wenlock graptolites from Prairie Creek, southern Mackenzie Mountains, Northwest Territories

1988 ◽  
Vol 25 (12) ◽  
pp. 1955-1971 ◽  
Author(s):  
Alfred C. Lenz

A moderately rich fauna of graptolites, comprising species dominated by Monograptus (sensu stricto), Retiolites, Stomatograptus, and Cyrtograptus is documented from Prairie Creek, southern Mackenzie Mountains, Northwest Territories. Graptolites of the upper Llandovery Monograptus turriculatus, Monograptus spiralis, and Cyrtograptus sakmaricus zones and of the Wenlock "unnamed zone" and Cyrtograptus rigidus and Monograptus testis – Cyrtograptus lundgreni zones are recognized. The species composition of these zones is significantly different from corresponding zones elsewhere in the Canadian Cordillera.Twenty-six species are described and illustrated, and of these, two are new: Stomatograptus canadensis and Cyrtograptus preclarus; and two species, Monograptus aff. riccartonensis and Cyrtograptus aff. sakmaricus might also be new. Several species, particularly Monograptus praecedens, Monograptus veles, and Monograptus cf. mutuliferus strigosus have not been prevously reported in North America.

1992 ◽  
Vol 6 ◽  
pp. 305-305
Author(s):  
Mahito Watabe

The late Miocene Chinese hipparions are morphologically diversified showing similarity to both western Old World's and North American forms. Two Chinese taxa that are phylogenetically related to western Old World's forms are Hipparion fossatum (= H. forstende) from Baode (Shanxi) and H. hippidiodus from Qingyang (Gansu) and Baode. The former is related to H. mediterraneum and the latter to H. urmiense - platygenys from the Turolian localities in the western Old World. H. fossatum and H. hippidiodus are associated with the “dorcadoides” (open-land) and “mixed” faunas in northern China. Hipparion fossatum that is characterized by POF located close to the orbit co-occurs with large and morphologically specialized form, H. dermatorhinum in Baode (Loc.30). H. hippidiodus with reduced POF is discovered with smaller H. coelophyes in Loc. 43, 44 (Baode) and Loc. 115 (Gansu).The hipparions associated with the “gaudryi” (forest) fauna are characterized by well defined and small POF located far from the orbit. Those forms are: H. platyodus from Loc. 70; H. ptychodus from Loc. 73; H. tylodus from Hsi-Liang in Yushe - Wuxiang basins; and H. sefvei from Loc. 12 at Xin-an in Henan province. H. coelophyes from Baode (Loc.43 & 44) and Qingyang (Loc. 115) also show similar facial morphology to the these forms, although it has small size and shallow POF. Those forms are similar in facial and dental morphology to Hipparion sensu stricto and some species of Cormohipparion in North America.The assemblages of Chinese hipparions are composed of two groups whose members are phylogenetically similar to the forms from both western part of Eurasia and North America. The “gaudryi” fauna is considered younger than the other two on the basis of faunal analyses. The similarity in hipparionine taxonomy between northern China and North America in the latest Miocene is an evidences for possible faunal interchange(s) occurred during that period, as suggested by taxonomic analyses on carnivores and proboscideans in eastern half of Eurasia and North America.


1953 ◽  
Vol 85 (8) ◽  
pp. 294-296 ◽  
Author(s):  
W. W. Judd

Studies of the goldenrod gall caused by Eurosta solidaginis Fitch have been made by various authors who reared insects from the galls in North America, e.g. Hughes (1934), Milne (1940) and Ping (1915). Snyder (1898) described the emergence of an adult fly from a gall in Illinois. In Canada, insects have been reared from galls collected in Manitoba and the Northwest Territories by Brodie (1892), in Quebec by Fyles (1894) and in Ontario by Harrington (1895). An opportunity has been taken recently to examine specimens reared by Dr. G. Beall from galls collected at Chatham, Ontario in 1930 and to rear insects from galls in the vicinity of London, Ontario.


1980 ◽  
Vol 112 (S112) ◽  
pp. 1-92 ◽  
Author(s):  
D.D. Munroe ◽  
Ray F. Smith

AbstractThe systematics of Acalymma sensu stricto of North America including Mexico are revised. Acalymma sensu stricto is defined and distinguished from the other species groups of Acalymma. Sixteen species are discussed including four new species: A. blomorum, A. palomarense, A. invenustum, and A. luridifrons all from Mexico. Three new subspecies of A. blandulum (LeConte) are described: blandulum (LeConte) new status, nigriventre, and yucatanense. Acalymma coruscum costaricense Bechyné is placed as a synonym of A. innubum (Fabricius). Keys are presented to all species and subspecies. Habitus and male genitalia drawings are given for all species and distribution maps are given where appropriate.


1997 ◽  
Vol 71 (6) ◽  
pp. 1109-1124 ◽  
Author(s):  
Li Guo-Qing ◽  
Mark V. H. Wilson ◽  
Lance Grande

Review of recently collected material of Eohiodon from North America suggests that there are two valid species, E. rosei (Hussakof) and E. woodroffi Wilson. Eohiodon falcatus Grande is identical to E. woodruffi in known skeletal features and nearly all meristic features and is treated as a junior synonym of the latter. The fossil genus Eohiodon Cavender differs from Hiodon Lesueur, which is known from both fossil and extant species, in numerous meristic and osteological features. The caudal skeleton in Eohiodon is nearly identical to that in Hiodon.The traditionally accepted Notopteroidei, containing Lycopteridae, Hiodontidae, and Notopteridae, is a polypheletic group. The Asian fossil family Lycopteridae is not more closely related to Hiodontidae than it is to other taxa in the Osteoglossomorpha, but is sister to all other Osteoglossomorpha. The Hiodontiformes sensu stricto, including only the family Hiodontidae, is the sister-group of the Osteoglossiformes. This family is not more closely related to notopterids than to other taxa in Osteoglossiformes. The Notopteridae are most closely related to the Mormyroidea; together they and the fossil family Ostariostomidae constitute the sister-group of the Osteoglossoidei.Fossil records of Hiodontiformes sensu stricto and Notopteroidei indicate a widespread pre-Neogene biogeographic range of these freshwater teleosts, suggesting that extinction must have been involved in the Cenozoic evolution of these two osteoglossomorph sublineages.


1978 ◽  
Vol 15 (7) ◽  
pp. 1205-1207 ◽  
Author(s):  
Douglas A. Archibald ◽  
Alan H. Clark ◽  
Edward Farrar ◽  
U Khin Zaw

K–Ar dating of magmatic biotite, and of hydrothermal biotite and muscovite, demonstrates that quartz monzonite intrusion and exoskarn scheelite mineralization at Cantung, N.W.T., took place over a brief interval in the Upper Cretaceous (ca. 91 Ma). The regional age relationships of magmatic and ore-forming activity in the Logan–Mackenzie Mountains are poorly defined, but it is tentatively inferred that tungsten mineralization may have been related to a late stage in the plutonic development of the area.


2021 ◽  
Vol 4 (1) ◽  
pp. 001-014
Author(s):  
MATHIAS JASCHHOF

Twenty-four fossil gall midges (Cecidomyiidae) described from 1917–2020 from Mesozoic deposits, mostly ambers, are reviewed. Information from the original publications is used as the basis for reinterpretation, when such is regarded as appropriate here. As a result, the fossil record of cecidomyiids from the Mesozoic comprises representatives of the following subfamilies and tribes, all mycophagous (numbers in parentheses refer to species described): Catotrichinae (1); Micromyinae: Catochini (2), Amediini (1), Campylomyzini (1), Micromyini (2) and Aprionini (1); Winnertziinae: Heteropezini (2), Diallactiini (4) and Winnertziini (1); Porricondylinae: Dicerurini (1). Other Winnertziinae (3) and Micromyinae (5) cannot be classified to tribe because information on critical morphological structures is unavailable; they are thus considered incertae sedis. Members of the Lestremiinae sensu stricto are unrecorded from the Mesozoic, as are any Cecidomyiinae (the only subfamily containing phytophages and predators). Commonly occurring reasons for misinterpretation of amber fossils are the non-recognition of artefacts and the unfamiliarity with group-specific literature regarding prevailing taxonomic concepts and the morphological diversity found in Cecidomyiidae. These causes as well as obvious differences between neontological and paleontological taxonomic practices are discussed. Amediini trib. nov. Jaschhof, 2021 is introduced as a new tribe of the Micromyinae, to absorb the genera Amedia Jaschhof, 1997 (extant, North America, type genus), Amediella Jaschhof, 2003 (extant, New Zealand) and Eltxo Arillo & Nel, 2000 (extinct, Alava amber). A diagnosis of the new tribe is given. Krassiloviolini Fedotova & Perkovsky, 2017 is a new junior synonym of Heteropezini Schiner, 1868. Amediini Plakidas, 2017 and Zarqacecidomyius singularis Kaddumi, 2007 are nomina nuda.


1984 ◽  
Vol 48 (1) ◽  
pp. 156 ◽  
Author(s):  
N. M. Simmons ◽  
M. B. Bayer ◽  
L. O. Sinkey

2002 ◽  
Vol 18 (5) ◽  
pp. 775-794 ◽  
Author(s):  
Luci Ferreira Ribeiro ◽  
Marcelo Tabarelli

Four structural types of cerrado vegetation were examined to test the following hypotheses: (1) there are predictable changes in woody plant density, species richness and life-history strategies from one structural type to another; and (2) plant species composition in the less-rich structural types represent particular and impoverished subsets of those found in the richer ones. The study was conducted at Fazenda Palmares (5°33′S, 42°37′W) Piauí State, Brazil. A 47% decrease in woody plant density between cerradão (forest) and the least-dense type of cerrado sensu stricto (scrub) was associated with a 40% decrease in species richness. The percentage of lower-layer species was reduced by 29% in the least dense type of cerrado sensu stricto compared to cerradão. The proportion of species that flower and fruit during the rainy season was also reduced by one third. Species were not distributed as impoverished subsets along the cerradão–cerrado sensu stricto gradient. It is argued that the reduction in woody plant density and richness is partly due to factors limiting the occurrence of species with particular life-history strategies. The species composition of structural types is affected by the ‘mass effect’ and also by surrounding biotas, which provide species that colonize particular types of cerrado vegetation. Both these processes reduce the likelihood that the species composition in the poorer structural types are simple subsets of those present in the richer types.


1990 ◽  
Vol 27 (1) ◽  
pp. 129-144 ◽  
Author(s):  
P. K. Kaiser ◽  
J. V. Simmons

The transport mechanism of some rock avalanches of the Mackenzie Mountains in the Yukon and Northwest Territories of Canada is reassessed on the basis of evidence collected during fieldwork and by comparison with results from numerical simulations of the debris flow mechanism. A new hypothesis of glaciation-related transport is advanced as an alternate explanation of apparently very mobile rock avalanches with anomalous travel distances. By the example of the Avalanche Lake slide, it is demonstrated that the debris was most likely not deposited on the current topography but on valley glacier ice at an elevation of about 400–500 m above the valley bottom. This conclusion is supported by field evidence, an empirical runup relationship, and the results from numerical flow simulations. A qualitative interpretation of other debris deposits suggests that several events in the Mackenzie Mountains can be interpreted in the same manner. Key words: rock avalanches, rock slides, debris transport, debris flow modelling, Mackenzie Mountains, Northwest Territories.


2006 ◽  
Vol 43 (12) ◽  
pp. 1791-1820 ◽  
Author(s):  
D E Jackson ◽  
A C Lenz

Four graptolite biozones are recorded from the Arenig portion of the Road River Group in the Richardson and Mackenzie mountains in the Yukon and Northwest Territories. In ascending order, these zones are Tetragraptus approximatus, Pendeograptus fruticosus, Didymograptus bifidus, and Parisograptus caduceus australis (new). The Castlemainian stage may be represented by nongraptolitic massive bedded chert. The Arenig–Llanvirn boundary is drawn below the first occurrence of Undulograptus austrodentatus. Fifty-four graptolite taxa are present, and 16 of these species and subspecies are recorded for the first time in this deep-water biotope, namely, Didymograptus? cf. adamantinus, D. asperus, D. dilatans, D. cf. kurcki, D. validus communis, Holmograptus aff. leptograptoides, H. sp. A, Isograptus? sp. nov. A, I. ? dilemma, Keblograptus geminus, Pseudisograptus manubriatus harrisi, Ps. m. koi, Ps. m. janus, Ps. cf. tau, Xiphograptus lofuensis, and Zygograptus cf. abnormis.


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