NJG60-1-07
1980
An abnormal cranidium of the trilobite Calyptaulax norvegicus
60
1
87-88

A cranidium of Calyptaulax norvegicus Størmer from upper Ordovician strata in the Hadeland district of the Oslo Region is abnormally developed on one side. This abnormality comprises the development of two additional lobes between the 1p and 2p lobes ljnd of a large area behind the palpebral lobe. It is considered to be a tetatological feature present during the entire post-larval life of the trilobite.

0029-196X
Print