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EVENTS IN THE CONODONT HISTORY DURING THE SILURIAN IN ESTONIA

1993; Estonian Academy Publishers; Volume: 42; Issue: 2 Linguagem: Inglês

10.3176/geol.1993.2.03

1736-7913

Peep Männik, V Viira,

Ancient and Medieval Archaeology Studies

The evaluation of events in the Silurian conodont history is based on the stratigraphic distribution о! all conodont species (including unpublished new ones) recognized in Estonia.The diversity of conodont species is the highest in the upper Llandovery and lowermost Wenlock (Velise Formation and lower Mustjala Member).In the main part of the Wenlock and in the upper Silurian the species diversity is below the average, except the Sauvere and Himmiste beds of the Paadla Stage, where the number of species is somewhat higher.The greatest declinesin conodont diversity occurred in Mohkkiila, Mustjala, and Uduvere times.These disappearances coincide with the Sandvika, amorphognathoides resp.Ireviken, and siluricus resp.Lau extinction events by Jeppsson (1987Jeppsson ( , 1993)).The total and per taxon rate charts show the same tendencies although in some intervals the per taxon rate tends to over-emphasize the appearances and disappearances.The greatest innovations in the conodont evolution are noted in the Juuru and Ada- vere