Evolution in
            <i>Monograptus priodon</i>

Lenz, Alfred C.

doi:10.1111/j.1502-3931.1974.tb00902.x

Cited by 7 publications

(4 citation statements)

References 4 publications

(2 reference statements)

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“…The specimens resemble M. jlemingii in the distal width, thecal spacing and morphology. However, the increase in width in the proxim:al end is very slow, similar to that of M. priodon, corresponding to the lowest increase for M. jlemingii as indicated by Lenz (1974). Further, the proximal thecal overlap appears smaller than usual for the species.…”

Section: Monograptus Exiguus Primulusmentioning

confidence: 85%

Silurian graptolites from Washington Land, western North Greenland

Bjerreskov¹

1981

bullggu

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Fifty-six graptolite species and subspecies are described from the Silurian sediments of Washington Land and Hall Land, western North Greenland. The graptolite faunas indicate the following ages and zones: Middle Llandovery, the argenteus and convolutus Zones; Upper Llandovery, the turriculatus and spiralis Zones; probably the Llandovery to Wenlock transition; Lower Wenlock, the riccartonensis Zone; Uppermost Wenlock (?) and Lower Ludlow. The bulk of the graptolite species are well known, but some new minor morphological grades are recognised. Four new species and one new subspecies Pseudoclimacograptus (Clinoclimacograptus)? washingtoni, Plectograptus? intermedius, Monograptus kochi, Monograptus teicherti,– and Monograptus bjerringus schucherti – are erected. P. (C.)? washingtoni and P.? intermedius possess morphological characters which are referable to more than one previously described subgenus and genus. The retiolitid fills a gap in the known record of the retiolitids.

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Section: Monograptus Exiguus Primulusmentioning

confidence: 85%

Silurian graptolites from Washington Land, western North Greenland

Bjerreskov¹

1981

bullggu

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“…When more recent works (Lenz 1974;Gingerich 1976Gingerich , 1977Malmgren & Kennett 1981;Malmgren et a/. 1983;Raup & Crick 1981;Lazarus 1986;Murphy & Cebecioglu 1984,1987Murphy & Springer 1989; and many others) are added to the anecdotal literature pertaining to evolutionary patterns, it becomes apparent that there is an abundant supply of patterns.…”

Section: Methodsmentioning

confidence: 99%

Punctuated stasis and collateral evolution in the Devonian lineage of Monograptus hercynicus

Springer

Murphy

1994

LET

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The changes in the sicula of Early Devonian monograptid graptolite populations show a pattern that is described as punctuated stasis: two longer periods of stasis separated by a transitional population of shorter duration between them. The pattern differs from punctuated equilibrium in that anagenesis is involved rather than cladogenesis. The pattern has been observed in several widely separated areas (Nevada, Thuringia, Poland, Ural Mountains) and is an example of collateral evolution in graptolites. In this case, the collateral morphologic change occurs relatively rapidly in a large, globally distributed taxon. The study permits accurate correlation of the horizon of appearance of Monograptus hercynicus Pemer in the upper delta Zone (conodont zonation) of late Lochkovian age (Devonian) on a global scale. The partial integration of these two biostratigraphies constrains correlations between the shelly, shallow‐water biofacies and the deeper graptolitic biofacies. The pattern of punctuated stasis has been discovered in Lower Devonian strata of central Nevada, where 22 horizons in sequence were sampled. Statistical analyses were performed on 13 characters encompassing measurements of the sicula, thecae, and rhabdosome. Most of these characters do not exhibit sustained trends or punctuated changes. However, sicular width exhibits an abrupt increase over a short stratigraphic interval and is used to classify members of the group into four quantitatively defined morphotypes. This natural perturbation in the pattern of change is used to divide the lineage into paleospecies. This makes the segments of the lineage easy to identify and imparts stability to the classification and precision in biostratigraphy. The variation studies enable the ranges of the morphotypes to be used to further subdivide the stratigraphic record of the late Lochkovian. □Graptolites, Devonian, Lochkovian, evolution, punctuated stasis, biostratigraphy, MONOGRAPTUS, phylogeny.

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“…Urbanek ( 1958 ) described isolated material of M. priodon from glacial erratics from Poland. The material is fragmentary, but better preserved material from successions in Arctic Canada (Lenz 1974 ) shows details of the colony shape. Relief specimens of M. priodon are common in some glacial erratics and make the species one of the most attractive taxa to find (Fig.…”

Section: Silurian Graptolitesmentioning

confidence: 99%

Graptolites from glacial erratics of the Laerheide area, northern Germany

Maletz

Schöning²

2017

PalZ

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Ordovician and Silurian glacial erratics of the Laerheide area (Lower Saxony, north-western Germany) bear well-preserved graptolites. The faunas provide important information on the origin and transport direction of the sediments preserved in a kame, representing the Drenthe stadial of the Saalian glaciation. The faunas even include species not commonly encountered in the successions of mainland Sweden, from where the erratics presumably originated. The most common graptolites are from Upper Ordovician (Sandbian to Katian) limestones and from Katian black shales. More common, however, are greenish limestones, sand- and siltstones, often combined in the term ‘Grünlich-Graues Graptolithengestein’, in which upper Wenlock to Ludlow (upper Silurian) graptolites are common.

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Evolution in Monograptus priodon

Cited by 7 publications

References 4 publications

Silurian graptolites from Washington Land, western North Greenland

Silurian graptolites from Washington Land, western North Greenland

Punctuated stasis and collateral evolution in the Devonian lineage of Monograptus hercynicus

Graptolites from glacial erratics of the Laerheide area, northern Germany

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