Acta Palaeontologica Polonica
44, 1, 93-115
(1999) Kaim, A. & Niedzwiedzki, R. Abstract. A description of new ammonoid specimens (Acrochordiceras
aff. damesi, cf. Acrochordiceras sp. indet., Discoptychites
cf. dux, Paraceratites cf. trinodosus, cf. Balatonites
sp. indet., Beneckeia buchi) from Lower Muschelkalk (Anisian,
Middle Triassic) of Silesia (southern Poland) is presented. The description is
supplemented with a list of all hitherto found species of ammonoids in
Silesia, which was a southern part of the Germanic Basin during Anisian. Beneckeia
and Noetlingites are typical of epicontinental seas and appear
usually at the early part of transgression. Other ammonoids entered from the
Tethys into epicontinental sea of the Germanic Basin during maxima of
transgressions. Some of them (balatonitids, paraceratitits, bulogitids,
Discoptychites cf. dux, and probably Acrochordiceras aff. damesi)
were successful colonizers which established their own populations in Germanic
Basin and evolved towards morphologies typical for epicontinental seas. Other
(Beyrichites sp., Paraceratites binodosus and ?Trachyceras sp.)
are regarded as unsuccessful immigrants or empty shells drifted post-mortem
from the Tethys.
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