Abstrakt
Dendroids have palaeoecological potential but are underrated in general. The present study is focused on the interval from the Floian to the earliest Sandbian (Klabava, Šárka and Dobrotivá formations) in the Ordovician of the Prague Basin (Czech Republic).
It is based especially on the new datasets of all dendroid graptolites from the Šárka and Dobrotivá formations at our disposal combined with the data of the overall biodiversity in the studied interval. The analysis of diversity illustrates that there is a remarkable contrast in the studied period: dendroids declined when other groups flourished and the diversity in the Prague Basin reached the first of the two Ordovician maxima coeval with the GOBE.
The patterns of those shifts seem to be primarily influenced by local environmental changes, i.e. ecologically controlled in the Prague Basin. The decline of dendroid graptolites was apparently caused by the disappearance of habitats, represented by proper substrate in the oxygenated environment, due to a gradual but continuing sea level rise.
Our case study resulted in the distribution model providing a general example of local factors masking those global and exemplifying a significance of differentiation between global and local causes of the GOBE.