Agnostids from the Upper Cambrian of Västergötland, Sweden

Ahlberg, Per; Ahlgren, John

doi:10.1080/11035899609546247

Cited by 39 publications

(56 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As shown by Ahlberg and Ahlgren (1996) for Västergötland and by Ahlberg and Terfelt (2012) for Scania, several lower Furongian agnostoid species appear at the base of intervals characterizing the onset of new assemblages of the olenid fauna, i.e., Olenus spp. at the base of the Glyptagnostus reticulatus Zone and Parabolina spp.…”

Section: Appearances Of Exotic Trilobites In the Stratigraphic Columnmentioning

confidence: 99%

“…On a global scale, the weakly reticulated morphotype always precedes the strongly reticulated one (Peng et al 2004). In Scandinavia, G. reticulatus is represented by the strongly reticulated morphotype, i.e., G. reticulatus reticulatus, which occurs in the Olenus gibbosus through the Olenus truncatus zones (Ahlberg and Ahlgren 1996). In Laurentian sections, the FAD of Aphelaspis generally falls within beds with the strongly reticulated morphotype of G. reticulatus s.l., and the base of the Olenus Superzone sensu Nielsen et al (2014) can be correlated with the base of the Aphelaspis Zone.…”

Section: Systematic Descriptionsmentioning

confidence: 99%

“…In Scandinavia, the scheme based on olenids has been tied to that based on agnostoid arthropods (Terfelt et al 2008). Global correlation of the Furongian in Baltica with other palaeocontinents is possible through the presence of several intercontinentally distributed agnostoids (Ahlberg and Ahlgren 1996;Ahlberg and Terfelt 2012).…”

Section: Alum Shales and Their Faunal Compo-sitionmentioning

confidence: 99%

“…sp., Hypagnostus sp. and Peratagnostus obsoletus (Kobayashi, 1935), appear in its upper part (Ahlberg and Ahlgren 1996;Ahlberg 2003). So far, no barren interval has been observed at the base of this zone.…”

Section: Appearances Of Exotic Trilobites In the Stratigraphic Columnmentioning

confidence: 99%

“…parvifrons (Linnarsson, 1869) and Agnostus (Homagnostus) obesus (Belt, 1867), whereas phase 3, beginning at the base of the Parabolina brevispina Zone (Text- fig. 3), corresponds to the re-appearance of Agnostus (Homagnostus) obesus, and the ranges of Pseudagnostus cyclopyge (Tullberg, 1880), Tomagnostella orientalis (Lazarenko, 1966), and Agnostus (Homagnostus) ultraobesus Lermontova, 1940 (Ahlberg andAhlgren 1996;Ahlberg and Terfelt 2012).…”

Section: Appearances Of Exotic Trilobites In the Stratigraphic Columnmentioning

confidence: 99%

See 4 more Smart Citations

Exotic trilobites from the uppermost Cambrian Series 3 and lower Furongian of Sweden

Żylińska¹,

Weidner²,

Ahlgren³

et al. 2015

Acta Geologica Polonica

Self Cite

View full text Add to dashboard Cite

ABSTRACT:Żylińska, A., Weidner, T., Ahlgren, J. and Ahlberg, P. 2015. Exotic trilobites from the uppermost Cambrian Series 3 and lower Furongian of Sweden. Acta Geologica Polonica, 65 (1), 21-67. Warszawa.Seventeen taxa of exotic trilobites representing eight families are described from the olenid-and agnostoid-dominated strata of the uppermost Cambrian Series 3 and lower Furongian alum shale facies of Sweden and from glacial erratic boulders of Denmark. Only five taxa are assigned to species level, i.e., Maladioidella abdita (Salter, 1866), Olentella rara (Westergård, 1922), Pedinocephalus peregrinus (Henningsmoen, 1957), Ptychoparia pusilla (Westergård, 1922), and Westergaardella olenorum (Westergård, 1922), whereas the others are left under open nomenclature or remain unrecognized. Most are described for the first time from the Cambrian of Scandinavia. Their affinities point to a strong connection with East Gondwana, Laurentia, Kazakhstania and Siberia. Exotic trilobites appear in the succession directly after periods of very low oxygen concentration in the Alum Shale Sea; their occurrences correspond to the ranges of agnostoid arthropods in the succession and seem to be linked to global transgressive events causing an influx of cool and/or oxygen-depleted waters onto the shelf of the Baltica palaeocontinent.

show abstract

Section: Appearances Of Exotic Trilobites In the Stratigraphic Columnmentioning

confidence: 99%

Section: Systematic Descriptionsmentioning

confidence: 99%

Section: Alum Shales and Their Faunal Compo-sitionmentioning

confidence: 99%

Section: Appearances Of Exotic Trilobites In the Stratigraphic Columnmentioning

confidence: 99%

Section: Appearances Of Exotic Trilobites In the Stratigraphic Columnmentioning

confidence: 99%

See 3 more Smart Citations

Exotic trilobites from the uppermost Cambrian Series 3 and lower Furongian of Sweden

Żylińska¹,

Weidner²,

Ahlgren³

et al. 2015

Acta Geologica Polonica

Self Cite

View full text Add to dashboard Cite

show abstract

Proposed GSSP for the base of Cambrian Stage 9, coinciding with the first appearance of Agnostotes orientalis, at Duibian, Zhejiang, China

Shanchi

Babcock

Zuo

et al. 2009

Sci. China Ser. D-Earth Sci.

View full text Add to dashboard Cite

Exposed in natural outcrops near the Duibian Village, Jiangshan County, Zhejiang Province, China, the Duibian B section is proposed as the boundary stratotype for the base of an unnamed stage termed provisionally Cambrian Stage 9. The proposed position of the GSSP is 108.12 m above the base of the Huayansi Formation, at a horizon coinciding with the first appearance of the cosmopolitan agnostoid trilobite Agnostotes orientalis. This horizon coincides also with the first appearance of the cosmopoli-tan polymerid trilobite Irvingella angustilimbata. The section fulfills all the requirements for a GSSP, and the horizon can be constrained not only by the primary stratigraphic marker (A. orientalis) but also with secondary biostratigraphic, chemostratigraphic, and sequence-stratigraphic correlation tools. The first appearance of A. orientalis is one of the most readily recognizable levels in Cambrian, and can be correlated with precision to all paleocontinents

show abstract