Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 18. 1996. (Budapest, 1996)

Fig. 1. Location map of the Balaton Highland showing the main features of the Late Anisian to Early Ladinian paleogeography (Fig. 1). This is a necessary basis for demonstrating the distribution of different ammonoid genera or morphotypes in different paleoenvironments. Two submarine highs (shallower areas) and an intervening, deeper basin system can be outlined. The submarine highs were active carbonate platform in the mid-Anisian (Pelsonian) times, then submerged and, in the time interval examined (from the Camunum to the Avisianum subzone), they were pelagic plateaus. In these times the top of the highs must have been below the euphotic zone, between 100 and 200 m water depth, whereas the depth of the basins is estimated at 300-400 m. These difference in the depth of water is expected to be mirrored in the distribution of ammonoids. Fortunately, three of the six sections studied are situated on the former pelagic plateaus (Szentantalfa, Vászoly, Szentkirályszabadja), while the other three (Mencshely, Felsőörs, Vörösberény) fall into the basin areas. This makes a sound basis for a comparison and a study of the environmental distribution. WANG & WESTERMANN (1993) outlined the major morphogroups and habitats of the Triassic ammonoids and gave impressive synthesising bathymétrie diagrams for the Early, Middle and Late Triassic. For the purpose of the present paper, the most important Middle Triassic morphogroups and corresponding habitats (with depth ranges) can be summarized as follows: (1) Planulates + depressed coronates. Morphology: Whorls are evolute, depressed, sometimes with tabulate or carinatesulcate venter, the sculpture is variable. Middle Triassic examples: Ceratiies, Progonoceratites, Reiflingites. Habitat: "platform", with 30-100 m depth range.