Аннотация:Sponges played a crucial role in the shaping of Cambrian marine ecosystems,commonly being principal filter feeders among the benthos. While calcified archaeocyathswere main Cambrian reef builders, spiculate and soft sponges were ubiquitous elements ofother level-bottom palaeocommunities. Of them, representatives of the family Protospongiidaepossessing a peculiar regular skeleton of cross-like spicules (stauractines) occurred inthe majority of the Cambrian Lagerstätten worldwide. A find of a Protospongia skeleton inthe middle Cambrian (c. 504–502 million years ago) of the south-eastern Siberian Platformfurther expands data on the global distribution of this genus and the family as a whole andprovides a new information on their specific skeletal morphology.