MILIOLIDAE - Acta Palaeontologica Polonica

24 EWA LUCZKOWSKA
resembling the contemporary species Q. lamarckiana, whose ancestral
form it probably is, is the most numerous. The occurrence of abundant
large and flat massiline forms of Quinqueloculina is also characteristic.
Assemblages of this type indicate the conditions of an inner shelf zone,
a depth not exceeding 50-80 m and warm water. The great variety of
species (38) suggests normal salinity.
An assemblage of the same type is observed at Benczyn in the southern
coastal zone and, consequently, the environment was probably similar.
The miliolid assemblages of the same age found at Iwkowa, Zegocina,
Przecisz6w, Brzozowa and other localities are also a similar type.
The salt clays at Wieliczka are younger than those at Korytnica and
the miliolids met with in them point to a somewhat different environment.
The main feature of the Wieliczka assemblage is the occurrence of a large
number of specimens against a reduced number of species (24) compared
with the assemblages from Karsy and Korytnica. The abundance of
specimens of Quinqueloculina akneriana QS and Q. triangularis QS comes
to the fore; the massiline forms of these species are rare, instead the
specimens of Pyrgo and Pyrgoella are considerably more numerous and
larger. Biloculinella and Nummoloculina appear as well, and at the same
time the number of quinqueloculine and triloculine species decreases. This
suggests deeper water, below 100 m, and judging by the vertical distribution
of Biloculinella and Nummoloculina in the Adriatic Sea the depths
may have been about 200-250 m. A decrease in the number of species
indicates a distance from the coast or a change in the chemical composition
of water.
In the Upper Tortonian the connection with the Vienna Basin through
the Moravian Gate was broken but that with the Ukraine and Moldavia
persisted. The sea assumed characters of a bay, occupying approximately
the same area as in the Lower Tortonian, but was shallower and with
a belt of arenaceous and calcareo-detritic littoral deposits, especially in its
north-eastern part. Its salinity, however, did not deviate much from the
normal, which is evidenced by the richness of genera and species.
Gliwice Stare is a typical locality in the western part of this bay, with
deposits containing the Upper Tortonian microfauna. Its miliolid assemblage
is, as a rule, the same type as that at Wieliczka, Le. it consists mainly
of members of Quinqueloculina, big specimens of Pyrgo, Nummoloculina
and Biloculinella, but also of a number of forms belonging to other species,
e.g. Cycloforina, Hauerina, Miliolinella, Pyrgoella, Affinetrina (formerly
Triloculina). Except for a few species that they have in common, e.g. Cycloforina
contorta, Quinqueloculina regularis and Q. pygmaea, most of the
species found at Gliwice Stare are absent from Wieliczka. Agglutinating
species, like those of Sigmoilopsis and Siphonaperta, play an important
part among them, and the whole assemblage shows a greater variety of
species (39). All these observations suggest that the depth was smaller