Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Gondolella

Sortuj według:

Ogranicz wyniki do:

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Gradual evolution of conodontophorids in the Polish Triassic

100%

Dzik J., Trammer J.

Acta Palaeontologica Polonica

1980

tom 25

nr 1

A monospecific continuum of populations of the conodont genus Gondolella occurs in a 23 m thick limestone set at the Anisian/Ladinian boundary in the southwest margin of the Holy Cross Mts, Poland. The change in distribution of morphological characteristics of the platform element is gradual and consists in an increase in contribution of morphologically juvenile stages to the fossil populations. Purely ecological interpretation of this trend as a continuous change in population dynamics is refuted. The trend reflects a true evolution. The other elements of the apparatus Gondotella do not undergo any significant changes, except possibly for the pl element ("Enantiognathus"). Time span separating fossil populations with non-overlapping standard-deviation ranges of diagnostic features sets actually the limit to recognition of temporal subspecies. This is also the limit to precision of biostratigraphic zonation based upon temporal taxa. It is here proposed to introduce a nomenclatorial difference between temporal and geographical (or biological) subspecies by insertion of a dash between specific and subspecific names.

Ograniczanie wyników

1 Acta Palaeontologica Polonica

1 Dzik J.

1 Trammer J.

1 1980

Wyniki wyszukiwania

Gradual evolution of conodontophorids in the Polish Triassic