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- New Cambrian vermiform organisms from Burgess Shale-type deposits of the
western United States
Abstract: Foster JR, Sroka SD, Howells TF, Cothren HR, Dehler CM, Hagadorn JW; Vol. 97, issue 3, pages 269 - 288
We report new occurrences of scalidophorans, enteropneusts, and other soft-bodied taxa in several middle Cambrian (Miaolingian) formations of the western United States. Among these are the first occurrence of the tubicolous priapulid worm Selkirkia Walcott, 1911 from the Ophir Formation of Utah and possibly from the Bright Angel Formation of Arizona (both Glossopleura Assemblage Biozone, Wuliuan). We document additional Selkirkia willoughbyi Conway Morris & Robison, 1986, S. columbia Conway Morris, 1977, and possible S. spencei Resser, 1939, from the Drum Mountains Wheeler fauna (Wheeler Formation of Utah; Bolaspidella Zone, Drumian). Selkirkia spencei occurs in the Spence Shale Member of the Langston Formation of Idaho (Wuliuan), from which we also describe more specimens. The enteropneust tube Margaretia Walcott, 1931 is quite common at some levels of the Wheeler Formation in the Drum Mountains of Utah, and new Margaretia specimens are also illustrated from the Wheeler Formation in the House Range and the Spence Shale in the Wellsville Mountains. The Wheeler Formation in the Drum Mountains also contains a Spartobranchus-like enteropneust, other possible enteropneusts, and additional undetermined wormlike organisms gen. et sp. indet. Several other taxonomically enigmatic organisms, burrows, or coprolites also occur in the Wheeler faunas of the Drum Mountains and House Range. These occurrences hint at greater diversity of scalidophorans and enteropneusts in the Wheeler ecosystems than has been previously documented, and extend the geographic distribution of the scalidophorans to the Ophir and possibly the Bright Angel formations in western Laurentia.
- The trilobite Serrodiscus Richter & Richter from Iberia, with systematic
review of the genus and its international correlation through the Cambrian
Series 2.
Abstract: Collantes L, Mayoral E, Liñán E, Gozalo R, Pereira S; Vol. 97, issue 3, pages 289 - 317
Serrodiscus is considered one of the first trilobite genera showing global distribution during the Cambrian and a key component for the international correlation of this period. However, this genus encompasses many poorly documented species, ambiguous diagnoses or characters that depend on taphonomy and deformation based on one single specimen. Thus, in the present work, we carry out a systematic overview of the genus, evaluating the taphonomic and deformational variability of a large number of specimens from the same locality and horizon. In addition, and due to the difficulty of making synonymy decisions, closely related species are grouped into three different groups taking into consideration morphologic, stratigraphic and palaeobiogeographic data: bellimarginatus group, scattered along Avalonian and western Gondwanan margins; speciosus group, extending over the Laurentian domain; and daedalus group, being restricted to eastern Gondwana (Australia), North China and, partially, Siberia. Besides, the regional correlation through the early Cambrian of Iberia is arranged, describing specimens from both Ossa-Morena and Central Iberian zones, with a time interval restricted to the upper Marianian Stage. Regarding the biostratigraphy and palaeobiogeography of the genus, Serrodiscus has been reported from Laurentia, Taconic Allochthon, Greenland, Baltica, western and eastern Avalonia, western Gondwana margin, Siberia, North China and eastern Gondwana, with a temporal distribution along with the Cambrian Series 2.
- Middle Anisian (Bithynian to Illyrian', Middle Triassic) Ammonoidea
from Rüdersdorf (Brandenburg, Germany) with a revision of Beneckeia
Mojsisovics, 1882 and notes on migratory pathways
Abstract: Siegel F, Wiese F, Klug K; Vol. 97, issue 3, pages 319 - 361
Bithynian and Pelsonian (Anisian, Middle Triassic) Ammonoidea are generally rare in the Germanic Basin. Here, we describe ammonoids from the Jena and Rüdersdorf formations (Lower Muschelkalk) of Rüdersdorf (Brandenburg, Germany). This locality is peculiar in its isolated situation and its comparatively high diversity in ammonoids. This outcrop yielded several assemblages encompassing eight species: Balatonites ottonis (Buch, 1849), B. balatonicus (Mojsisovics, 1873), B. egregius (Arthaber, 1896), Beneckeia buchi (Alberti, 1834), Bulogites zoldianus (Mojsisovics, 1882), “Ceratites” antecedens (Beyrich, 1858), Discoptychites dux (Giebel, 1853) and Noetlingites strombecki (Griepenkerl, 1860). When the geographic distribution of these species are compared, it becomes evident that immigrants from the southeast and the southwest met in that region. Such immigrations were only possible during transgressions. Balatonites balatonicus, B. egregius and B. zoldianus are recorded from the area for the first time. Beneckeia is revised with a focus on Ben. buchi, one of the few true endemites of the Germanic Basin, using synchrotron data to describe its early ontogeny. The holotype of “Ceratites” antecedens is figured for the first time and a lectotype for Balatonites egregius is designated.
- New data on conodonts and ostracods of the Katkoyeh Formation (Lower-Upper
Ordovician) at the Banestan Section of East-Central Iran:
biostratigraphical and palaeobiogeographical significance
Abstract: Poursalehi F, Voldman GG, Bahrami A, Salas MJ, Ameri H; Vol. 97, issue 3, pages 363 - 384
Ordovician marine sedimentary sequences occur in several widely separated structural blocks in Iran, along the northern margin of Gondwana. In northern Kerman Province, the Ordovician sedimentary interval is known as the Katkoyeh Formation, which encompasses ˜ 70-300 m of siliciclastic rocks with scarce carbonate and thick pyroclastic beds in its upper part. Previous studies provided several ages for the Katkoyeh Formation, puzzled by the limited number of palaeontological studies, mostly based on spot samples, the presence of regional important stratigraphic gaps, and the inherent structural complexity of the area. In order to adjust the depositional time of the Katkoyeh Formation, a systematic sampling for microfossils was conducted in the Banestan Section, located about 12 km northwest of the city of Zarand, in the vicinity of the Banestan village. Based on the occurrence of important biostratigraphic species, we recorded three conodont intervals in ascending order in the Katkoyeh Formation, namely the Rossodus manitouensis/ Paltodus deltifer Concurrent Range Zone (Tremadocian, Lower Ordovician), the Juanognathus variabilis Range Zone (Floian, Lower Ordovician), and the Icriodella superba Range Zone (Katian-'Hirnantian, Upper Ordovician). The conodont biostratigraphy is discussed and analysed, improving the Ordovician intrabasinal correlation of Iran as well as correlation with distant palaeobiogeographic domains. The Upper Ordovician conodont assemblage is accompanied by two new species of ostracods: Satiellina zarandensis sp. nov. and Ceratopsis persicus sp. nov., both suggesting palaeobiogeographical affinities mainly with Gondwana and peri-Gondwanan regions.
- Early Silurian (mid-Sheinwoodian) palynomorphs from the
Loděnice-Špičatý vrch, Prague Basin, Czech Republic
Abstract: Bek J, Štorch P, Tonarová P, Libertín M; Vol. 97, issue 3, pages 385 - 396
Dispersed spores, cryptospores, scolecodonts, acritarchs, prasinophytes and chitinozoans, dated by graptolites as being middle Sheinwoodian (early Wenlock, ca 432 Ma), are described from the Loděnice-Špičatý vrch locality, Prague Basin, Czech Republic. Palynomorphs were macerated from a specimen (stored in the National Museum, Prague), with fragments of Cooksonia sp. and the zonal index graptolite Monograptus belophorus giving precise stratigraphic position within Monograptus belophorus Biozone. Important is the oldest occurrence of monolete spores. The number of spore taxa indicate that minimally six types of early vascular plants and probably two to three types of cryptosporophytes grew on the Svatý Jan Volcanic Island in the Prague Basin. The ecology of the first cryptospore and trilete spore producers within Sheinwoodian-Přídolí interval is discussed with special focus on first two globally important key events (after Homerian glaciation and during Přídolí) for earliest vascular land plants. The combination of palynological and palaeobotanical records confirms important role of volcanic islands of the Prague Basin for the evolution of early land plants.
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