Skolekodonty i konodonty z obszaru Polski oraz problemy ich systematyki

Hubert Szaniawski

Abstrakt


SCOLECODONTS AND CONODONTS FROM POLAND AND THE PROBLEM OF THEIR SYSTEMATICS

Summary
The scolecodonts and conodonts have several features in common. They represent elements of complex multi-element organs. In the fossil state usually single elements are found which highly complicates their systematics. Two different systematics are used for both scolecodonts and conodonts the parataxonomic svstematics for isolated elements and the taxonomic for the whole apparatuses. In the case of the systematics of the scolecodonts the main difficulty is related to the fact that they usually represent isolated elements of apparatuses consisting of numerous differentiated elements and the homologous elements of entirely different apparatuses are often very similar to one another. The proposition of uniting the systematics of isolated scolecodonts and apparatuses up to generic level, recently made by Kozur (1971), seems premature. According to the present author this will be possible in the future but it should be preceded by extensjve studies on fossil apparatuses and the revision of several collections of isolated scolecodonts. The jaws of polychaetes of the families Glyceridae and Goniadidae are the exception here as they are not united in multi-element apparatus and they may be identified within the frame of the natural systematics. In Poland, the studies were primarily carried out on the whole jaw apparatuses of the polychaetes. Thanks to the introduction of appropriate searching techniques the majority of fossil apparatuses known were described from our country. Nevertheless, the knowledge of the polychaete jaw apparatuses is far from being complete. For example, nothing is known about the apparatuses from the Carboniferous, Cretaceous and Cenozoic of Poland, whereas the Lower Paleozoic apparatuses are relatively well known. The problems encountered in the systematics of conodonts are still more complex as neither systematic position of the conodont-bearing animal nor the function of an organ to which they belonged are known. Besides isolated conodonts and their natural assemblages derived from a single animal, assemblages selected with the use of the statistics are often described under separate names. According to the present author these attempts to reconstruct conodont apparatuses are advisable but a separate systematics, independent of the systematics for single elements, should be used in the descriptions. The experience gained from the studies on scolecodonts shows the limited applicability of the statistic techniques for these purposes. In Poland the conodonts are intensively studied since the end of the sixties. The number of publications is, however relatively high on account of a remarkable importance of the conodonts for the stratigraphy. In PoIand, Ordovician and Devonian conodonts are relatively the best known, whereas single, rather short papers were devoted to the conodonts of the Cambrian, Silurian and Permian. A little is also known about the conodonts of the Carboniferous age.

Pełny tekst:

PDF