Glyptagnostus and associated trilobites in the United States

Palmer, Allison R.

doi:10.3133/pp374f

Cited by 54 publications

(65 citation statements)

References 4 publications

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“…Some species, such as Glyptagnostus reticulatus (Angelin, 1851), appear to be genuinely widespread geographically (e.g., Westergård 1947, Palmer 1962, Peng & Robison 2000, although often only in outer shelf and basinal facies (e.g., Robison 1976). However, as discussed below, evidence for broad distributions of many other species is equivocal at best.…”

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The Cambrian (Sunwaptan, Furongian) agnostoid arthropod Lotagnostus Whitehouse, 1936, in Laurentian and Avalonian North America: systematics and biostratigraphic significance.

Westrop¹,

Adrain²,

Landing³

2011

Bull. Geosci.

119

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Restudy of type and other material shows that the Cambrian (Sunwaptan, Furongian) agnostoid arthropod Lotagnostus americanus (Billings, 1860), far from being distributed globally, can be identified with confidence only at its type locality of Quebec. As such, it is ill-suited as an index for international correlation. Lotagnostus obscurus Palmer, 1955, from Nevada is not a synonym of L. americanus and is most similar to other effaced species from Australia. Sclerites from Avalonian Canada are represented by perhaps as many as two species, one of which is L. germanus (Matthew, 1901), and the other is similar to the type species, L. trisectus (Salter, 1864). However, loss of information due to compaction makes L. trisectus difficult to interpret in its type region of Avalonian Britain, and possible occurrences in other areas are therefore questionable at best. At the current state of knowledge, this species name should not be applied outside of Avalonian Britain. Aside from L. obscurus, which may possibly appear in slightly older strata, all Laurentian occurrences are confined to Upper Sunwaptan successions. Most are in the Illaenurus and Prosaukia pyrene zones, although review of material assigned to L. hedini (Troedsson, 1937) in western Newfoundland suggests that this species may occur, albeit questionably, only in the basal Skullrockian Phylacterus saylesi Fauna; indeterminate species occur in the Keithia schucherti Fauna in the latter region. Occurrences in Avalonian Canada are all from the upper Peltura Zone, and are likely somewhat younger (Saukiella junia Subzone and correlatives) than those in Laurentian successions

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confidence: 99%

The Cambrian (Sunwaptan, Furongian) agnostoid arthropod Lotagnostus Whitehouse, 1936, in Laurentian and Avalonian North America: systematics and biostratigraphic significance.

Westrop¹,

Adrain²,

Landing³

2011

Bull. Geosci.

119

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“…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. However, Palmer (1962) DESCRIPTION: Cranidium with low relief, trapezoidal, width at level of palpebral lobes almost equal to total cranidial length; posterior width about 1.5 of total cranidial length. Glabella 68−73% of total cranidial length, forwardly tapering, bluntly terminated anteriorly.…”

Section: Systematic Descriptionsmentioning

confidence: 99%

“…The type species of the genus stated by Jell and Adrain (2003), Conocephalites depressus Shumard, 1861, is not valid as explained earlier by Palmer (1953). REMARKS: Palmer (1953Palmer ( , 1954Palmer ( , 1960Palmer ( , 1962Palmer ( , 1965a discussed the concept of the genus, provided emended diagnoses, and described the Laurentian species. Shergold and Cooper (1985), Shergold and Webers (1992) and Cooper et al (1996) described species from the Furongian of Antarctica.…”

Section: Systematic Descriptionsmentioning

confidence: 99%

“…The specimen is closest to A. subdita Palmer, 1962 from the Steptoean Aphelaspis Zone in Nevada, USA (Palmer 1962(Palmer , 1965a (Ivshin 1955(Ivshin , 1956. Species assigned to Olentella are listed in Shergold et al (1976Shergold et al ( , 2000 and Romanenko (1988).…”

Section: Systematic Descriptionsmentioning

confidence: 99%

“…However, Glyptagnostus reticulatus sensu lato is a species composed of at least two morphotypes, the weakly reticulated G. reticulatus angelini (Resser, 1938) and the strongly reticulated G. reticulatus reticulatus (Angelin, 1851). The two taxa are regarded either as valid (Palmer 1962) or invalid subspecies, with the two morphotypes intergrading into one another (Pratt 1992). On a global scale, the weakly reticulated morphotype always precedes the strongly reticulated one (Peng et al 2004).…”

Section: Systematic Descriptionsmentioning

confidence: 99%

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

Żylińska¹,

Weidner²,

Ahlgren³

et al. 2015

Acta Geologica Polonica

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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.

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East-Gondwana/Laurentia trilobite connections—What do they tell us?

Palmer

2005

Geosci J

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Glyptagnostus and associated trilobites in the United States

Cited by 54 publications

References 4 publications

The Cambrian (Sunwaptan, Furongian) agnostoid arthropod Lotagnostus Whitehouse, 1936, in Laurentian and Avalonian North America: systematics and biostratigraphic significance.

The Cambrian (Sunwaptan, Furongian) agnostoid arthropod Lotagnostus Whitehouse, 1936, in Laurentian and Avalonian North America: systematics and biostratigraphic significance.

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

East-Gondwana/Laurentia trilobite connections—What do they tell us?

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