Rozwój poglądów na przynależność systematyczną niektórych rodzajów rodziny Anomalinidae Cushman

Eugenia Gawor-Biedowa



The representatives of the family Anomalinidae Cushman 1927 are characterized by both vast geographical distribution and wide stratigraphic range. They become the subject of extensive studies since the XIX c. They were usually described under various generic names, and when Reuss (1862) proposed the family Rotaliidae, several genera of trochospirally coiled forms were placed m this family. The family Anomalinidae was proposed by Cushman (1927) for the forms with aperture equatorial and sometimes extending on test walls. The latter family, as interpreted by Cushman, also comparised some highly specialized forms with modified aperture. The family Anomalinidae is genetically related to the family Rotaliidae Ehrenberg. According to Cushman (1948), the transitional link is represented by the genus Discorbis, and particularly by its representatives with chitinous lining at early ontogenic stages and traces of agglutinated layer. However, some typical representatives of Anomalinidae, as e.g. the genus Gavelinella, were placed in the family Rotaliidae even by Cushman. Some subsequent authors rejected the family Anomalinidae (see e.g. Galloway, 1933, Glaessner, 1945; Brotzen, 1942) whereas others accepted it with some modifications (e.g. Vassilenko, 1954, 1959; Loeblich and Tappen, 1964). According to the present author, the genera placed by Loeblich and Tappan (1964) in the subfamily Anomalininae of the family Anomalinidae should be separated in two subfamilies because of differences in location of the lateral part of the aperture. The forms with interiomarginal-equatorial aperture extending on the ventral side, those with the aperture situated on ventral side, as well as those with aperture terminal but related with ventral side during the ontogeny, should be left in the subfamily Anomalininae. The forms with the aperture extending on the dorsal side, and their allies with a modified aperture, should be placed in a new subfamily. The rich assemblage of foraminifers from, the Upper Albian-Lower Turonian of the Polish Lowland was assigned to the family of Anomalinidae after a detailed analysis of the position of embryonic chamber in the test, the mode of test coiling, degree of evolutness of the test, location and course of lateral part of the aperture, and microstructure of test wall.

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