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Late Viruan [Caradoc] polychaete jaws from North Estonia and the St.Petersburg region

100%

Hints O.

Acta Palaeontologica Polonica

1998

tom 43

nr 3

471-516

An abundant, diverse and well-preserved fauna of jaw-bearing polychaetes (Annelida, Polychaeta, Eunicida) was recovered from the late Viruan (Caradoc) of eight borehole sections in North Estonia and the St. Petersburg region. Altogether 46 species are encountered. Two new genera, Incisipnon with type species I. incisus (Kielan-Jaworowska, 1966) and Estonioprion with type species E. maennili sp. n., and five new species (Incisiprion edentulus, Polychaetura kielanae, Ramphoprion bialatus, Ramphoprion peterburgensis, Estonioprion maennili) are introduced. In addition 17 new species are described under open nomenclature. The taxonomy is based on jaw apparatuses, fused or reconstructed ones. Many species found in Estonia have been previously described from the erratic boulders of Poland. The studied polychaete fauna was confined to the North Estonian Confacies, a shallow-water carbonate shelf, which constituted favourable habitats for Ordovician polychaete worms. The stratigraphical ranges of many prevalent polychaete species exceed the interval studied. However, a few species seem to be restricted to particular horizons and may be useful for stratigraphy. Polychaete assemblages of certain time intervals, characterized by very steady species composition and relative frequencies of different taxa, were spatially widespread within the North Estonian Confacies. Based on the changes in the assemblages, some stratigraphical levels, like the boundary beds of the Idavere and Jõhvi stages, can be traced within the study area. The jawed polychaete faunas of Baltica and Laurentia probably had several species in common during the Caradoc.

Ordovician polychaeturid polychaetes: Taxonomy, distribution and palaeoecology

63%

Hints O., Eriksson M. E.

Acta Palaeontologica Polonica

2010

tom 55

nr 2

309-320

The fossil polychaete family Polychaeturidae is considered as monogeneric and comprises four species of the genus Pteropelta. Pteropelta, originally established on isolated scolecodonts (the carriers), is revised and the apparatus−based Polychaetura is shown to be a junior synonym of Pteropelta. In addition to Pteropelta gladiata and Pteropelta kielanae, Pteropelta hubertisp. nov., and Pteropelta sp. A are herein described from the Upper Ordovician of Estonia and Sweden. Polychaeturids include some of the most common and characteristic scolecodont−bearing polychaetes in the Ordovician of Baltoscandia. They first appeared in the early Darriwilian (Mid Ordovician), flourished in the Late Ordovician and disappeared in the early Silurian. The distribution patterns of individual polychaeturid species infer regional biostratigraphical potential. Polychaeturids were geographically widespread during the Ordovician and have been recorded from at least three palaeocontinents.

Ograniczanie wyników

2 Acta Palaeontologica Polonica

2 Hints O.

1 Eriksson M. E.

1 2010

1 1998

Wyniki wyszukiwania

Late Viruan [Caradoc] polychaete jaws from North Estonia and the St.Petersburg region

Ordovician polychaeturid polychaetes: Taxonomy, distribution and palaeoecology