Morphobiological study of the brachiopods of the order Chonetida

A comparative morphological study of the brachiopods of the order Chonetida revealed a key part of the development of the shell structures connected with the feeding and respiration organs, such as the lophophore, musculature, and mantle, in the morphological evolution of the group. The general trends revealed in the development are adaptive and were restored based on morphofunctional analysis. Against the background of these trends, the correlative changes of the shell shape and its external ornamentation led to the repeated appearance of homeomorphs, whose similarity cannot be explained by adaptation. The phylogeny of the superfamily Anoplioidea is described as an example.