MILIOLIDAE - Acta Palaeontologica Polonica

16 EWA LUCZKOWSKA
Sigmoilopsis foeda, Pyrgo amphiconica and Pyrgoella ventruosa. In other
regions, e.g. in the Bochnia-Gd6w area and in the Holy-Cross Mts, the
Miliolidae of this zone are still poorer in species and represented only by
small numbers of Cycloforina suturalis and Sigmoilinita tenuis.
Upper Tortonian
Zone with Neobulimina longa. - Between the Lower Tortonian zone
with Uvigerina costai and Upper Tortonian zone with Neobulimina longa
there was a period of formation of chemical deposits, in which no microfauna
developed. Its slow development occurs after this period, but the
Miliolidae do not playa major role yet. The microfaunaI assemblages
of this zone are composed partly of the species existing earlier in the zone
with Uvigerina costai and partly of new species. This is not the case with
the Miliolidae, among which the species known from the Lower Tortonian,
like Quinqueloculina regularis, Sigmoilinita tenuis, Pyrgo inornata and
P. truncata, are still observed.
Zone with Hanzawaia crassiseptata. - It come to a great development
of the Upper Tortonian microfauna in this zone, at which there also appear
a number of new miliolid species. In the coastal region the boundary
between the two zones of the Upper Tortonian is not sharp, there being
transitions between them or a direct succession of a great development
of the benthonic microfauna, comprising new species, after the period of
formation of chemical deposits. The Miliolidae develop more abundantly
than previously and, although the species of the lower zone of the Upper
Tortonian still persist among them, a few species not encountered before
appear as well. The Miliolidae from Gliwice Stare in Upper Silesia make
a typical example. The most characteristic species of this assemblage are:
Quinqueloculina buchiana QS and MS, Q. parakneriana QS and MS,
Q. regularis, Q. pygmaea and Q. spondiungeriana - as relicts of the Lower
Tortonian forms; Cycloforina contorta, C. gracilis, C. lachesis, C. lucida
(a group of related forms, characterized by a rough surface with short
incised lines and a tendency to carinate peripheries of the chambers) and
C. suturata; a group of several species of the genus Hauerina, i.e.
H. aspergilla, H. compressa, H. plana, H. podolica, H. tumida and Pseudohauerina
ornatissima, of which only P. ornatissima and H. tumida were
recorded from lower layers; Sigmoilopsis foeda, Siphonaperta granulata,
S. mediterranensis, Miliolinella selene, M. valvularis, Affinetrina gualtieriana,
A. planciana, Biloculinella labiata, Pyrgo clypeata, P. inornata,
P. lunula, P. truncata, Pyrgoella controversa, P. globiformis, P. ventruosa,
Sinuloculina consobrina, S. microdon, S. nitens, Triloculina angularis,
T. eggeri, Sigmoilinita tenuis and Nummoloculina contraria, out of which
Cycloforina suturata, Siphonaperta granulata, Affinetrina gualtierana,