Tremadocian and Floian (Ordovician) linguliformean brachiopods from the Stavelot–Venn Massif (Avalonia; Belgium and Germany)

Lower Ordovician linguliformean brachiopods from the Stavelot–Venn Massif (Belgium and Germany) are described systematically for the first time. The material comprises specimens from the Jalhay (Solwaster Member) and Ottré (Les Plattes Member) formations of Tremadocian and Floian ages, respectively. The Solwaster Member yielded a relatively diverse assemblage of nine species of lingulide (e.g. Lingulella lata, Lithobolus sp., Broeggeria sp.) and acrotretide (Acrotreta? sp.) whereas only one siphonotretide species (Celdobolus sp.) is recognised from the base of the Les Plattes Member where it is associated with conodonts of the Paroistodus proteus Zone. The assemblage from the Solwaster Member, although not abundant, is much more diverse than that of the contemporaneous Chevlipont Formation in the Brabant Massif (Thyle Valley, Belgium). Some of the taxa identified in the Stavelot–Venn Massif represent some of the youngest occurrences and first occurrences documented in Avalonia.

The Lower Ordovician Brachiopod Syntrophla sp., cf. S. arethusa (Billings 1862) from South Catcher Pond, Northeastern Newfoundland

Canadian Journal of Earth Sciences ◽

10.1139/e73-040 ◽

1973 ◽

Vol 10 (3) ◽

pp. 427-430 ◽

Cited By ~ 2

Author(s):

A. J. Boucot

Keyword(s):

North American ◽

Volcanic Rocks ◽

Lower Ordovician ◽

The Lower Ordovician North American Province brachiopod genus Syntrophia is recognized for the first time from northern Newfoundland. It occurs together with other Lower Ordovician fossils (trilobites and conodonts) in a limestone lens interbedded with volcanic rocks that may belong to the Lush's Bight Group.

Jujuyaspis borealis and associated trilobites and conodonts from the Lower Ordovician of Texas and Utah

10.1017/s0022336000028249 ◽

1987 ◽

Vol 61 (1) ◽

pp. 112-121 ◽

Cited By ~ 9

Author(s):

James H. Stitt ◽

James F. Miller

Keyword(s):

United States ◽

South America ◽

North American ◽

The United States ◽

International Agreement ◽

Lower Ordovician ◽

Central Texas ◽

North And South America ◽

First Time ◽

North And South

Jujuyaspis borealis is reported from earliest Ordovician (North American usage) limestones in central Texas and western Utah, the first time this species has been recognized in the United States. Jujuyaspis is a widespread olenid trilobite that occurs near the base of the Tremadoc Series in a variety of lithologies in North and South America, Europe, and Asia. When international agreement is reached on the exact horizon at or near the base of the Tremadoc Series that is to be used as the Cambrian–Ordovician boundary, Jujuyaspis will likely prove to be a very useful taxon for recognition of the boundary interval.

Stratigraphic framework for the CambrianOrdovician rift and passive margin successions from southern Quebec to western Newfoundland

Canadian Journal of Earth Sciences ◽

10.1139/e02-078 ◽

2003 ◽

Vol 40 (2) ◽

pp. 177-205 ◽

Cited By ~ 46

Author(s):

Denis Lavoie ◽

Elliott Burden ◽

Daniel Lebel

Keyword(s):

Sea Level ◽

Continental Margin ◽

Passive Margin ◽

Early Cambrian ◽

Sea Level Fluctuations ◽

Late Cambrian ◽

Head Groups ◽

Stratigraphic Framework ◽

Lower Ordovician ◽

The Taconian Humber Zone stretches from western Newfoundland to southern Quebec. The Early Cambrian slope succession in Newfoundland is found in the Curling Group, whereas in Quebec, various units were deposited during that first time slice. Biostratigraphic data allow correlation of the Curling Group with the Labrador Group in Newfoundland and with the newly time-constrained slope succession in Quebec. The end of the riftdrift transition is marked by a sea-level lowstand at the end of the Early Cambrian. The Middle Cambrian to latest Early Ordovician passive margin history recorded five cyclic sea-level fluctuations. Three of these cycles are recorded in the shallow-marine Middle to Late Cambrian platform (Port au Port Group) and slope sediments preserved in the Cow Head and Northern Head groups in Newfoundland. The biostratigraphic information assists correlation with Cambrian passive margin units in Quebec. Major sea-level lowstands are recognized along the continental margin in earlymiddle Late Cambrian (Steptoan) and in late Late Cambrian (Sunwaptan). Even if the Quebec succession can be tied with its Newfoundland correlative, some significant differences in the nature of Upper Cambrian slope conglomerates argue for a tectonic control on the depth of erosion of the Cambrian continental margin. The Lower Ordovician record of the passive margin consists of two depositional cycles (TremadocianArenigian) separated by a sea-level lowstand. This last event is well expressed in platform succession and is also recognized in conglomerate units found in the slope succession.

Recognition of Macluritella (Gastropoda) from the Upper Cambrian of Missouri and Nevada

10.1017/s0022336000028183 ◽

1987 ◽

Vol 61 (1) ◽

pp. 56-61 ◽

Cited By ~ 6

Author(s):

Ellis L. Yochelson ◽

B. L. Stinchcomb

Keyword(s):

Upper Cambrian ◽

Lower Ordovician ◽

Open-coiled euomphalacean gastropods have been identified for the first time in the Upper Cambrian Eminence Dolomite of Missouri. These gastropods have a triangular whorl profile and are conspecific with Hyolithes walcotti described from the Upper Cambrian of Nevada. That species is questionably reassigned to the gastropod genus Macluritella, hitherto known only from the Lower Ordovician of Colorado.

Late Cambrian conulariids from Wisconsin and Minnesota

10.1017/s0022336000033035 ◽

2000 ◽

Vol 74 (5) ◽

pp. 828-838 ◽

Cited By ~ 18

Author(s):

Nigel C. Hughes ◽

Gerald O. Gunderson ◽

Michael J. Weedon

Keyword(s):

Cross Sections ◽

Lower Cambrian ◽

New Genus ◽

Mississippi Valley ◽

Upper Cambrian ◽

Late Cambrian ◽

Lower Ordovician ◽

Two New Species ◽

First Time ◽

Taxonomic Evaluation

Several localities within the heterolithic facies of the St. Lawrence Formation (Upper Cambrian) of Wisconsin and Minnesota yield specimens with phosphatic exoskeletons, quadrate cross sections composed of four equidimensional faces each bearing a midline, and possible holdfast attachment during life. These specimens are here referred to the order Conulariida, class Scyphozoa. Their fine, tuberculate surface ornament and serially invaginated midline structure serve to define a new genus, Baccaconularia, to which two new species, B. robinsoni and B. meyeri, are assigned. Conularia cambria Walcott 1890, also from the Cambrian of the northern Mississippi Valley and long dismissed as a misidentified trilobite fragment, is illustrated photographically for the first time. This species occurs in rocks stratigraphically beneath the St. Lawrence Formation. Specimens assigned to this species by Walcott are conulariids, but lack features now considered diagnostic of either Conularia or Baccaconularia. Walcott's material is insufficient to permit detailed taxonomic evaluation, and we isolate this name to this material, pending the collection of additional, better preserved specimens. Together, Baccaconularia and Conularia cambria contain the oldest large conulariids, and these narrow a stratigraphic gap between other large conulariids known from the Lower Ordovician onwards, and smaller fossils with conulariid affinities known only from Lower Cambrian rocks.

Cruziana: A stratigraphically useful trace fossil

Geological Magazine ◽

10.1017/s001675680005439x ◽

1968 ◽

Vol 105 (4) ◽

pp. 360-364 ◽

Cited By ~ 18

Author(s):

T. P. Crimes

Keyword(s):

Trace Fossil ◽

British Isles ◽

Upper Cambrian ◽

North Wales ◽

Lower Ordovician ◽

New Localities ◽

Area North ◽

SUMMARYCruziana semiplicata (Salter) is recorded, generally in abundance, from previously known and new localities within Upper Cambrian (Ffestiniog) sediments in Snowdonia, and the Portmadoc area, North Wales. C. furcifera (D'Orb) is recorded for the first time in the British Isles from four localities within Lower Ordovician (Arenig) sediments on St. Tudwal's Peninsula, North Wales.It is shown that each of these species is of limited but different range, and it is suggested that they could be useful in distinguishing between otherwise unfossiliferous Cambrian and Ordovician strata.

Jujuyaspis and associated trilobites from the Mungok Formation (Lower Ordovician), Yongwol, Korea

10.1017/s0022336000017595 ◽

2000 ◽

Vol 74 (6) ◽

pp. 1031-1042 ◽

Cited By ~ 10

Author(s):

Dong Hee Kim ◽

Duck K. Choi

Keyword(s):

North America ◽

South America ◽

North China ◽

Lower Ordovician ◽

America South ◽

Mungok Formation ◽

The trilobite genus Jujuyaspis Kobayashi, 1936, an index fossil of earliest Ordovician age, is recorded from the Yosimuraspis Zone of the Mungok Formation (Lower Ordovician) for the first time in Korea. The Yosimuraspis Zone comprises Yosimuraspis vulgaris Kobayashi, 1960; Jujuyaspis sinensis Zhou in Chen et al., 1980; Elkanaspis jilinensis Qian in Chen et al 1985; and pilekid genus and species indeterminate. Closely comparable faunas to the Yosimuraspis Zone are well represented in North China. The occurrence of Jujuyaspis allows the correlation of the Yosimuraspis Zone with the earliest Ordovician faunas of North America, South America, and Scandinavia, and suggests that the Cambrian-Ordovician boundary in Korea be placed at the base of the Yosimuraspis Zone.

The upper Tremadocian (Lower Ordovician) graptolite Ancoragraptus from Yiyang, South China

10.1666/12-146 ◽

2013 ◽

Vol 87 (6) ◽

pp. 1129-1135 ◽

Cited By ~ 1

Author(s):

Wang Wenhui ◽

Feng Hongzhen ◽

Li Lixia ◽

Chen Wenjian

Keyword(s):

Literature Review ◽

South China ◽

Global Scale ◽

High Potential ◽

Hunan Province ◽

Lower Upper ◽

Lower Ordovician ◽

Discovery of well-preserved specimens from the Nanba section in Yiyang, Hunan Province, in combination with a literature review, enabled us to re-evaluate and revise the graptolite genus Ancoragraptus. This is a genus of biradiate, multiramous anisograptids with horizontal to reclined rhabdosomes and free lower part of the metasicula and slightly isolated autothecal apertures. According to the revised definition, two species are included in Ancoragraptus, i.e., Ancoragraptus bulmani (Spjeldnæs, 1963) and Ancoragraptus psigraptoides Cho, Kim, and Jin, 2009. It is the first time that A. bulmani has been reported from China. The occurrences of Ancoragraptus reported worldwide are reviewed in the present study and found to be restricted to the lower upper Tremadocian. The restriction of Ancoragraptus in stratigraphical distribution makes it a taxon with a high potential for precise biostratigraphical correlation at both regional and global scale.

Dianulites Eichwald, 1829: An unusual Ordovician bryozoan with a high-magnesium calcite skeleton

10.1017/s0022336000027529 ◽

1999 ◽

Vol 73 (1) ◽

pp. 38-48 ◽

Cited By ~ 22

Author(s):

Paul D. Taylor ◽

Mark A. Wilson

Keyword(s):

Type Species ◽

Growth Form ◽

Rugose Corals ◽

Lower Ordovician ◽

Magnesium Calcite ◽

Ultrathin Sections ◽

High Magnesium Calcite ◽

Living Tissues ◽

First Time ◽

Benthic Animals

The ‘granular’ wall microstructure of the Ordovician stenolaemate bryozoan Dianulites Eichwald, 1829, has been studied using ultrathin sections, scanning electron microscopy (SEM), analytical SEM, and cathodoluminescence. The timing of recrystallization and the presence of microdolomite inclusions in the skeletal walls implies that the original skeleton consisted of high-magnesium calcite (HMC). Although found in some modern cheilostomes, HMC has not been recorded in living stenolaemate bryozoans, but appears to have also been present in Nicholsonella and a few other Ordovician genera traditionally assigned to the trepostomes or cystoporates. The Russian type species of Dianulites, D. fastigiatus Eichwald, 1829, is revised and recorded for the first time in North America from the Fillmore Formation (Lower Ordovician) of Utah. Unusually among bryozoans, D. fastigiatus has turbinate, cone- or horn-shaped colonies, straight to slightly curved, with zooids opening on the flat, broad end of the cone; the sides of the cone comprise calcified exterior walls. This growth-form resembles some solitary rugose corals and other benthic animals thought to have lived with all but their tops buried in soft sediment. Such an interpretation is supported in Dianulites by the scarcity of epibionts on the exterior walls of the cone and by the occurrence of specimens comprising stacks of subcolonies, suggesting periods of partial burial of the living tissues by sediment.

First Middle Ordovician conodont record related to key graptolites from the western Puna, Argentina: perspectives for an integrated biostratigraphy and correlation of the Central Andean Basin

Andean geology ◽

10.5027/andgeov47n1-3261 ◽

2020 ◽

Vol 47 (1) ◽

pp. 144 ◽

Cited By ~ 1

Author(s):

Blanca A. Toro ◽

Susana E. Heredia ◽

Nexxys C. Herrera Sánchez ◽

Florencia Moreno

Keyword(s):

High Resolution ◽

South China ◽

Middle Portion ◽

Middle Ordovician ◽

Lower Ordovician ◽

Conodont Fauna ◽

First Time ◽

Overlying Strata

Recent biostratigraphic studies on the western argentine Puna recorded the Middle Ordovician conodont Baltoniodus cf. B. navis (Lindström) for first time, related to key graptolite taxa of the Central Andean Basin. The analyzed material comes from the lower and middle thirds of the turbidite succession exposed at the Huaytiquina section, Salta Province, which was previously assigned to the “Coquena” Formation. The conodont fauna was recovered from the calcareous sandstone beds intercalated in the middle portion of this unit, and it is composed by species of the genera Baltoniodus, Gothodus, Trapezognathus, Drepanoistodus, Drepanodus, and Protopanderodus, among others. The conodont association indicates a middle Dapingian (Dp2) age, linking the conodonts of the Argentine Puna with those from Baltoscandinavia and South China. The conodont productive levels also contain graptolites assignable to Tetragraptus bigsbyi (Hall) and Isograptus sp. They are located overlying strata bearing Azygograptus lapworthi Nicholson and underlying deposits with Xiphograptus lofuensis (Lee). The graptolite associations are indicating a Dapingian age (Dp1-Dp2) for the lower and middle portions of the “Coquena” Formation. The current findings from the western Puna, as well as the record of Azygograptus lapworthi related to the early Dapingian (Dp1) index conodont Baltoniodus triangularis in the Argentine Cordillera Oriental, are suggesting that a high-resolution correlation between both geomorphological regions is possible. This also documents that the Cordillera Oriental as well as the Puna were connected parts of the Central Andean Basin, during the interval from the Lower Ordovician (Floian) to the Middle Ordovician (Dapingian), instead of corresponding to the source and infill sectors of the basin, respectively. Furthermore, the regional and global correlations are discussed, and the potential of the Ordovician successions of the Argentine Puna for future advances on conodont-graptolite high-resolution biostratigraphy is highlighted.