Zmiany patologiczne u Crassicollaria Remané, 1962 (Tintinnida)

Wiesław Nowak


Pathologic changes in Crassicollaria Remané, 1962 (Tintinnida)

The Berriasian Cieszyn Limestones exposed at Jasienica near Bielsko- -Biala contain a microfossil assemblage comprising several tintinnids species belonging to the genus Crassioollaria Remane, among others: Crassioollaria intermedia (Durand Delga), Cr. ex aff. brevis Remane, Cr. massutiniana (Colom), Cr. parvula Remane , Cr. elongata Now., Cr. posttithonica Now., Calpionella alpina Lorenz , C. elliptica Cadisch, Calpionellopsis simplex (Colom), Calpionellites darderi (Colom), Tintinnopsella carpathica (Murgeanu et Filipescu) , T. longa (Colom), T. batallerii Colom, Remaniella cadischiana (Colom), Stenosemellopsis hispanica (Col o m), which are accompanied by a large number of aberrant forms (see Ta'ble and Fig. 1 in Polish text). The presence of a ring-like callosity or swelling below the base of the flange indicate that these forms belong to the genus Crassioollaria Remane, 1962. The most frequent aberrations comprise: local deformations of the test or of the flange, asymetrical development of the callosity at the base of the flange or its abnormally large dimensions, and general lack of proportion in the various elements of the lorica. These aberrations occurring together in various combinations produce the uniqueness of shape of the individual abnormal forms. Besides shapes of lorica known in various species of the genus Crassioollaria: conical, elliptical, cylindrical, elliptical-cylindrical, wide-elliptical and lanceolate, in the aberrant forms the lorica are narrow-elliptical, wide- and narrow cylindrical, lenticular, club-shaped or wedge-shaped. The flange is straight, concordant with the long axis of the lorica, or arched and widening sidewards. A large majority of the aberrant forms have medium or large length (L = 70— 105 mu), while their width is strikingly small (1 = 15.6—46.8 mpi), and the width o f the aperture reaches a maximum value of 25 mu. Such a large variety of aberrant forms accompanying the Crassioollaria species listed above in the described assemblage of Berriasian age from Jasienica, suggest the possibility of a period of maximum differentiation o f the population related with adaptative radiation. The individual forms show examples of superposition or combination of features characteristic for various species, belonging not only to the Crassicollaria genus. Among others (especially notable are very narrow, strongly elongated lanceolate forms resembling the Neocomian genera Amphorellina, Salpingellina and Coxliellina. Taking into account the nearly complete lack of représentants of the Crassicollaria genus in the youngest Berriasian assemblages (with the exception of very small, poorly developed, single specimens of Cr. parvula Rem.), it is supposed that the aberrant forms described here did never achieve a widespread development and thrived for a relatively short time. Their disappearance was probably coeval with the general regression of the Crassicollaria genus. The example of an assemblage of aberrant forms presented in this paper could be possibly regarded as another confirmation of the thesis well established for various groups of organisms according to which the periods of adaptative radiation are inevitably followed by degeneration and total regression. The appearance of the large number of aberrant forms is regarded by the present author as intimately related with the above processes. The importance of the discussed processes over various geographical areas outside the Carpathians is suggested by the observations on assemblages of aberrant forms published by G. Colom (1948) from the Berriasian of the Baleares, and by R. Zia (1965) from the Berriasian of Toscany.

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