Academician Milan Herak's Main Contribution to Palaeontology

Abstract

The main contribut ion of Herak's palaeontologicalresearch carried out over a long period of time, beganduring his early career in the Geological-PalaeontologicalMuseum in Zagreb between 1943 and 1952. Thereforehis first publications concerned the field of palaeontology.Within that scientific discipline Herak made asignificant contribution to the analysis of Triassic calcareollssponges from the "Syconcs" group (HERAK,[943,1944). He investigated and presented the morphological"characters" of five genera, and particularlythose species where, on newly discovered material, herecognized some new features. He also established anew genus and species O/igop/ag/a cal"ll/ca . All previouslyknown forms and their distribution were the subjectof this Herak's paper with special emphasis on thevertical distribution and lithogenesis of the group. Froma lithogenetic point, Herak highlights the genus Amblysip/IOI/el/a, as well as the genera Oligoplagia and H%coc/ia. Herak also drew palaeoecological conclusionsregarding the isolation of their habitat. He was onlyable to attr ibute stratigraphic value to two species:Colospongia dubia (Upper Ladinian) and Amblysiphonella rimorica (Middle Triassic)...