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1

Visean and Bashkirian ammonoids from Central Iran

Hairapetian V., Korn D., Bahrami A.

Acta Geologica Polonica

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2006

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Vol. 56, no. 3

229-240

EN

Two successions of Carboniferous sedimentary rocks in Central Iran yielded ammonoid assemblages from one horizon each. In the Ramsheh section, a siltstone with Neoglyphioceras yazdii n. sp. and Dombarites can be assigned to the latest Visean. The assemblage from the Shesh Angosht Mountain is more diverse with species of the genera Proshumardites, Eumorphoceras, Homoceras, Glaphyrites, Syngastrioceras, and Dombarocanites. This is the first time that the co-occurrence of the genera Eumorphoceras and Homoceras has been recorded. This fauna contains elements of the South Urals and Central Asian occurrences of Bashkirian ammonoids and suggests close palaeobiogeographic relationships.

2

Age, distribution, and phylogeny of the peculiar Late Devonian ammonoid Soliclymenia

Korn D., Niedźwiedzki R., Posieczek J.

Acta Geologica Polonica

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2005

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Vol. 55, no. 2

99-108

EN

New records of the triangularly coiled Soliclymenia paradoxa (MUNSTER, 1839) from Dzikowiec (Sudetes, Poland) allow the study of intraspecific variability. It can be demonstrated that at least three species within the genus Soliclymenia can be separated. The genus has a limited stratigraphic distribution within the .Wocklumeria Stufe. of the Late Devonian, but a wide geographic range within the tropical seas.

3

The mid-Famennian ammonoid succession in the Rhenish Mountains: the "annulata Event" reconsidered

Korn D.

Geological Quarterly

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2004

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Vol. 48, No 3

245--252

EN

The mid-Late Devonian pelagic sedimentary successions of the Rhenish Mountains and other regions show a double black shale horizon called the annulata Black Shale. It marks, at the species level, a prominent faunal turnover of ammonoids from the Prolobites delphinus Zone into the Platyclymenia annulata Zone. An analysis of ammonoid genera distribution, phylogenetic relationships, andmorphospace occupation demonstrates that the "annulata Event" does not correspond to a crisis of the group and does not fulfill the criteria of a major biotic event.

4

Morphometric evolution and phylogeny of Palaeozoic ammonoids. Early and Middle Devonian

Korn D.

Acta Geologica Polonica

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2001

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Vol. 51, nr 3

193-215

EN

A combination of methods from cladistics and stratophenetic analyses is used for a reconstruction of Early and Middle Devonian ammonoid phylogeny. The analyses are based mainly on principal characters such as conch geometry (coiling form, whorl expansion rate, whorl cross-section shape), septal geometry (form of septa, number, position, and shapes of lobes), and ornament (growth lines and ribs); a new classification scheme of the ancient ammonoid order Agoniatitida is proposed. It is subdivided into four suborders: Agoniatitina (paraphyletic), Gephuroceratina (monophyletic), Anarcestina (paraphyletic), and Pharciceratina (monophyletic). Morphometric analysis shows the unfolding of several morphological trends, such as the modification of coiling parameters, among the Early and Middle Devonian ammonoids. Two major independent lineages can be recognised in the phylogeny of the Middle Devonian ammonoids, the first represents the agoniatids in which the Gephuroceratina is nested, the second are the anarcestids which gave rise to the Pharciceratina. The new families Latanarcestidae, Tamaritidae, Atlantoceratidae, and Taouzitidae, as well as the new genera Taouzites, Croyites and Meragoniatites are introduced.

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Depositional setting of the Devonian/Carboniferous biohermal Bol'shaya Nadota Carbonate Complex, Subpolar Urals

Skompski S., Paszkowski M., Krobicki M., Kokovin K., Korn D., Tomaś A., Wrzołek T.

Acta Geologica Polonica

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2001

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Vol. 51, nr 3

217-235

EN

Multi-stage development of carbonate buildups has been recognised in the Bol'shaya Nadota Carbonate Complex, in the vicinity of the town of Inta (Subpolar Urals). The growth of typical stromatoporoid-coral bioherms, characteristic of the Middle-Late Devonian stage, was terminated by the appearance of the shallow water oolitic facies, most probably at the beginning of the Famennian. During the Visean stage the carbonate platform was reconstructed, but algarbrachiopod-coral bioherms were characterized by relatively small dimensiones and an interfingering with organodetrital-oolitic facies. Sporadically, the inter-mound facies is represented by goniatite-bivalve coquinas with two new goniatite species: Goniatites olysya sp.nov. and Lusitanoceras kusinae sp.nov. The persistence of biohermal sedimentation in the Bol'shaya Nadota area is most probably caused by the specific position of the region on the boundary of two sedimentary-structural units: Lemva and Elets Zones, which corresponded to a basinal and a tectonically-active elevated part of a platform margin respectively. The overall biotic composition of the Carboniferous bioherms from Bol'shaya Nadota, situated in the northern periphery of Laurussia, falls generally within the diversity spectrum of Lower Carboniferous mounds described from the southern margin of the continent.

6

Mantle expansion upon the conch in the Late Devonian ammonoid Erfoudites

Korn D.

Acta Geologica Polonica

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2000

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Vol. 50, no. 1

21-27

EN

Specimens of the Late Devonian ammonoid species Erfoudites rugosus sp. nov. from the Rhenish Massif of Germany show an additional wrinkled structure that covers the body chamber ornament. The pattern closely resembles the dorsal wrinkle layer known from many ammonoids; the course af the wrinkles is radial, partially following the growth line course. This wrinkle structure is interpreted as resulting from a secretion of the mantle, which expanded ventrally or dorsally over the conch.

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Devonian conodont and ammonoid succession of the eastern Tafilalt (Ouidane Chebbi section), Anti-Atlas, Morocco

Belka Z., Klug Ch., Kaufmann B., Korn D., Döring S., Feist R., Wendt J.

Acta Geologica Polonica

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1999

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Vol. 49, no. 1

1-23

EN

Devonian conodonts and ammonoids occurring in association in the Ouidane Chebbi section of the eastern Tafilalt (Anti-Atlas, Morocco) are described and analysed in terms of stratigraphy. The excellently exposed sequence spans the entire Devonian; it includes open-marine carbonates and shales deposited outside the tropical realm. Except for its Middle Devonian part, the Ouidance Chebbi section is not condensed. Although the sequence was only sampled in a preliminary fashion, most of it lithological units have been dated with some precision. The study is an attempt to enhance the precision in the correlation between the Devonian conodont and ammonoid sequences. Graphic correlation method was used for estimating the precise position of the zonal and stage boundaries for the Middle and Upper Devonian intervals. The stratigraphy of the Lower Devonian at Ouidane Chebbi is still poorly defined. The Eifelian/Givetian boundary is well constrained, especially by both conodonts and ammonoids. It occurs within the uppermost part of the Kacak Event-Level, a characteristic shale horizon that beginsin the ensensis Zone and ranges into the hemiansatus Zone. Biostratigraphic indications from conodonts show that the top of the Pharciceras limestone unit is located within the norrisi Zone and the Givetian/Frasnian boundary should be placed within the characteristic black styliolinites level of the Frasne Event. The onset of the Kellwasser facies falls within the Zone 12 (winchelli Zone) of the Frasnian and it extends into the rhomboidea Zone. The combined evidence from ammonoid and trilobite data suggests that the marine deposition persisted at Ouidane Chebbi at least up to the time of the Upper praesulcata Zone.