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

remark on the ecology of their Middle Triassic ammonoids, namely that "... Hungarites, Parakellnerites and Aplococeras lived preferentially in shallow waters ... whereas other ammonoid genera and species preferred deeper and/or open sea waters." This idea was not endorsed by the studies made on the Balaton Highland: none of the ceratitid ammonoid genera showed any definite relationship with the paleoenvironment. It has to be borne in mind, however, that active platforms (i.e. really shallow marine environments) were missing in the Balaton Highland in the studied interval; BRACK & RlEBER's observation may be valid in the surroundings of active platforms. In the quantitative approach, the proportions of the strongly ornamented "coronates" and the "sphaerocones" have been counted for three time horizons, i.e. three stratigraphie intervals: (1) Camunum + Pseudohungaricum subzones, (2) Reitzi subzone, (3) Avisianum subzone. These proportions are shown in Tables IL, III. and IV., according to stratigraphie intervals and localities. It is clear from these data that the proportion of the "coronates" is systematically lower in the basin areas than in the pelagic plateaus, whereas the "sphaerocones" show inverse relationship. The proportion of the other forms varies irregularly. The same relationship can be demonstrated diagrammatically on a series of maps (Figs 2, 3 and 4). Table II. CAMUNUM + PSEUDOHUNGARICUM SUBZONES (721 specimens) basin pelagic plateau Felsőörs Vörösberény Szentantalfa Vászoly "coronates" 11 % 25 % 24% 25 % "sphaerocones" 57% 44% 15 % 26% others 32% 31 % 61 % 49% Table III. REITZI SUBZONE (751 specimens) basin pelagic plateau Mencshely Felsőörs Vászoly Szkszabadja "coronates" 10% 14 % 39% 22 % "sphaerocones" 75% 82% 57% 69% others 15% 4% 4% 9%