Classification of Devonian Nautiloids

Flower, Rousseau H.

doi:10.2307/2421185

Cited by 13 publications

(15 citation statements)

References 2 publications

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“…Only Goldringia valnevenzis Zhuravleva, 1996 is known from the Late Pragian of Novaya Zemlya. However, the major dispersion events of rutoceratoids happened later during the Emsian and Eifelian, when rutoceratoids became widespread within the faunas of the Old World (Rutoceratidae, Ptenoceratidae) and of Eastern American (Rutoceratidae) realms (Flower 1945).…”

Section: Discussionmentioning

confidence: 99%

“…The Pragian Ptenoceras alatum (Barrande, 1865) and Ptyssoceras alienum (Barrande, 1865) were previously assigned to the rutoceratoids by Kummel (1964). Manda (2001) described the oldest known species of Goldringia Flower, 1945, G. gondola Manda, 2001, from the late Pragian Dvorce-Prokop Limestone. Turek (2007) also reported the latter species from the earliest Zlí-chovian (Emsian) strata of the Prague Basin (see Fig.…”

Section: Rutoceratoids In the Pragian Of The Prague Basinmentioning

confidence: 99%

“…We suggest that the mode of coiling and subsequent change in shell symmetry was rapidly changing during evolution and thus does not represent a very important diagnostic character. Hyatt (1883Hyatt ( -1884Hyatt ( , 1894, Flower (1945) and Zhuravleva (1974) overemphasised the taxonomic value of minor differences in the mode of shell coiling and used these differences to establish new genera of rutoceratoids. Turek (2007) noted that the intraspecific variability in shell coiling ranged from gyrocones to very low torticones (both sinistrally or dextrally coiled) in the Pragian Ptenoceras Hyatt, 1894 and the late Emsian Hercoceras Barrande, 1865, and consequently he synonymised some taxa that had been established based on minor differences in coiling.…”

Section: Rutoceratoids In the Pragian Of The Prague Basinmentioning

confidence: 99%

“…Dark lines visible on the abraded surface of the lectotype in the adapical part of the shell were formerly interpreted as colour pattern (Foerste 1930b, Kobluk & Mapes 1989, an opinion later refuted by Turek (1990, in press). Species assigned here to the Pseudorutoceras were previously placed in Goldringia Flower, 1945and Rutoceras Hyatt, 1884(e.g., Flower 1945, Zhuravleva 1974, Manda 2001. These genera differ from Pseudorutoceras in having distinct recurrent collars around the whole shell (e.g., Fig.…”

Section: Systematic Palaeontologymentioning

confidence: 99%

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Revision of the Pragian Rutoceratoidea Hyatt, 1884 (Nautiloidea, Oncocerida) from the Prague Basin

Manda¹,

Turek²

2009

Bull. Geosci.

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Superfamily Rutoceratoidea Hyatt, 1884 (Pragian to Frasnian, Devonian) includes nautiloid cephalopods having exogastric cyrtoceracone or coiled shells with periodic walls or raised growth lines (megastriae) forming ridges, sometimes modified in various ways into collars, frills, or different outgrowths. High disparity and intraspecific variability of the shell form and sculpture of the rutoceratoids are conspicuous among Early Palaeozoic nautiloids. Consequently, rutoceratoids are divided according to different patterns of growth structures into three families. Parauloceratidae fam. nov. (Pragian to Emsian) contains taxa with cyrtoceracone shells and simple recurrent ribs with ventral sinus. Family Hercoceratidae Hyatt, 1884 (Pragian to Givetian) comprises forms with periodically raised ridges with three lobes forming ventrolateral outgrowths during shell growth such as wings, nodes or spines. Family Rutoceratidae Hyatt, 1884 (Pragian to Frasnian) encompases taxa having growth ridges with ventral lobe transforming into undulated frills or distinct periodic collars (megastriae). All of these families had already appeared during early radiation of rutoceratoids in the Pragian. The early radiation of rutoceratoids is, however, adequately recorded only from the Prague Basin. Rutoceratoids become widespread within faunas of Old World and Eastern American realms later during the Emsian and especially Middle Devonian. Three new genera are erected: Parauloceras gen. nov., Otomaroceras gen. nov. and Pseudorutoceras gen. nov. The Pragian Gyroceras annulatum Barrande, 1865 is assigned to the genus Aphyctoceras Zhuravleva, 1974. Rutoceratoids are thus represented by six genera and eight species in the Pragian Stage of the Prague Basin. In addition, variability of shell coiling among rutoceratoids and its significance for their systematics are discussed

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Section: Discussionmentioning

confidence: 99%

Section: Rutoceratoids In the Pragian Of The Prague Basinmentioning

confidence: 99%

Section: Rutoceratoids In the Pragian Of The Prague Basinmentioning

confidence: 99%

Section: Systematic Palaeontologymentioning

confidence: 99%

See 2 more Smart Citations

Revision of the Pragian Rutoceratoidea Hyatt, 1884 (Nautiloidea, Oncocerida) from the Prague Basin

Manda¹,

Turek²

2009

Bull. Geosci.

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“…Cyrtoconic and breviconic nautiloid shells usually show some departure from straightness even in the earliest part of the shell, whereas the shell in Figure 13D does not. Thus, our specimen is most probably a protoconch of a longiconic orthoceratid nautiloid belonging to a species of Michelinoceras, Casteroceras, Arkonoceras, or Geisonoceras, all of which occur in the Middle Devonian rocks of eastern North America [110].…”

Section: Cephalopodsmentioning

confidence: 93%

A Mineralized Alga and Acritarch Dominated Microbiota from the Tully Formation (Givetian) of Pennsylvania, USA

Chamberlain

Brown

2016

Geosciences

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Sphaeromorphic algal cysts, most probably of the prasinophyte Tasmanites, and acanthomorphic acritarch vesicles, most probably Solisphaeridium, occur in a single 20 cm thick bed of micritic limestone in the lower part of the Middle Devonian (Givetian) Tully Formation near Lock Haven, Pennsylvania. Specimens are composed of authigenic calcite and pyrite crystals about 5-10 µm in length. Some specimens are completely calcitic; some contain both pyrite and calcite; and many are composed totally of pyrite. The microfossils are about 80 to 150 µm in diameter. Many show signs of originally containing a flexible wall composed of at least two layers. Some appear to have been enclosed in a mucilaginous sheath or membrane when alive. The acanthomorphic forms have spines that are up to 20 µm in length, expand toward the base, and are circular in cross-section. The microflora occurs with microscopic molluscs, dacryoconarids, the enigmatic Jinonicella, and the oldest zooecia of ctenostome bryozoans known from North America. The microalgal horizon lacks macrofossils although small burrows are present. Microalgae and acritarchs have been preserved via a complex preservational process involving rapid, bacterially-mediated post-mortem mineralization of dead cells. The microfossil horizon, and possibly much of the Tully Formation at Lock Haven with similar lithology, formed in a relatively deep, off-shore basin with reduced oxygen availability in the substrate.

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Orthocone Cephalopoden aus dem deutschen Unterkarbon

Schmidt¹

1956

Paläontol. Z.

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Classification of Devonian Nautiloids

Cited by 13 publications

References 2 publications

Revision of the Pragian Rutoceratoidea Hyatt, 1884 (Nautiloidea, Oncocerida) from the Prague Basin

Revision of the Pragian Rutoceratoidea Hyatt, 1884 (Nautiloidea, Oncocerida) from the Prague Basin

A Mineralized Alga and Acritarch Dominated Microbiota from the Tully Formation (Givetian) of Pennsylvania, USA

Orthocone Cephalopoden aus dem deutschen Unterkarbon

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