ICHNOLOGY OF THE LATE CAMBRIAN LION MOUNTAIN MEMBER OF THE RILEY FORMATION

2018 ◽  
Author(s):  
Ryan F. Morgan ◽  
◽  
Kristopher Lee Juntunen ◽  
Ashley Brooke Scott ◽  
Marion Landreth
Keyword(s):  
Late Cambrian

Early Ordovician alkali-ultramafic Zhilandy complex (Central Kazakhstan): structure and age of formation

2019 ◽  
Vol 484 (1) ◽  
pp. 61-65
Author(s):  
R. M. Antonuk ◽  
A. A. Tretyakov ◽  
K. E. Degtyarev ◽  
A. B. Kotov
Keyword(s):  
Complex Formation ◽  
Central Asian Orogenic Belt ◽  
Early Cambrian ◽  
Early Ordovician ◽  
Late Cambrian ◽  
Central Asian ◽  
Geochronological Study ◽  
Three Stages ◽  
Late Neoproterozoic ◽  
Quartz Monzodiorites

U–Pb geochronological study of amphibole-bearing quartz monzodiorites of the alkali-ultramafic Zhilandy complex in Central Kazakhstan, whose formation is deduced at the Early Ordovician era (479 ± 3 Ma). The obtained data indicate three stages of intra-plate magmatism in the western part of the Central Asian Orogenic Belt: Late Neoproterozoic stage of alkali syenites of the Karsakpay complex intrusion, Early Cambrian stage of ultramafic-gabbroid plutons of the Ulutau complex formation, and Late Cambrian–Early Ordovician stage of formation of the Zhilandy complex and Krasnomay complex intrusions.

LINGULIFORM BRACHIOPODS ACROSS THE STEPTOEAN/SUNWAPTAN (LATE CAMBRIAN) “BIOMERE” BOUNDARY IN THE GREAT BASIN, USA

2017 ◽  
Author(s):  
Rebecca L. Freeman ◽  
◽  
James F. Miller ◽  
Kevin R. Evans ◽  
Damon J. Bassett
Keyword(s):  
Great Basin ◽  
Late Cambrian

Circumocular suture and visual surface of “Cedaria” woosteri (Trilobita, Late Cambrian) from the Eau Claire Formation, Wisconsin

1997 ◽  
Vol 71 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Nigel C. Hughes ◽  
Gerald O. Gunderson ◽  
Michael J. Weedon
Keyword(s):  
North Central ◽  
Late Cambrian ◽  
Eau Claire

Rare specimens of the Late Cambrian primitive libristomate trilobite “Cedaria” woosteri from the Eau Claire Formation of north-central Wisconsin preserve an unusual and new ocular suture, and the impressions of lens facets. The suture is circumocular, but loops abaxially onto the ocular platform. The portion of the ocular platform that is enclosed by this suture and is fused with the visual surface is here termed the “ocular plate”. The size and arrangement of the lens facets show that “C.” woosteri possessed a holochroal eye, typical of that known in other Cambrian libristomate trilobites. This nearshore assemblage, while low in diversity, contains a disparate array of trilobite morphotypes.

A new Late Cambrian pentastomid and a review of the relationships of this parasitic group

2005 ◽  
Vol 96 (2) ◽  
pp. 163-176 ◽  
Author(s):  
Dieter Waloszek ◽  
John E. Repetski ◽  
Andreas Maas
Keyword(s):  
Systematic Position ◽  
Host Group ◽  
Upper Cambrian ◽  
Late Cambrian ◽  
Lower Ordovician ◽  
Stem Lineage ◽  
New Form ◽  
Available Information ◽  
High Degree ◽  
Derivatives Of

ABSTRACTPentastomida, tongue worms, are a taxon of about 130 species of parasites, living exclusively in the respiratory tracts of vertebrates. Three-dimensionally preserved Upper Cambrian larvae already demonstrate a high degree of adaptation to parasitism, striking morphological conservatism, and a high diversification by the Late Cambrian, thereby suggesting a likewise diversified host group. Not least due to their highly modified morphology, the systematic affinities of pentastomids remain controversial. The two major alternatives place the group as either close to branchiuran crustaceans or as stem-lineage derivatives of the Euarthropoda. To this set of Cambrian fossil representatives of the pentastomids we can add a new form from Lower Ordovician boundary beds from Sweden, most likely reworked from Upper Cambrian horizons. Based on this new species, named Aengapentastomum andresi gen. et sp. nov., and the available information about fossil and Recent pentastomids, we review the diverging ideas on the systematic position of this fully parasitic taxon.

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