sentences:  In particular, the expanded and flattened telson (the most posterior segment of the body) of "Slimonia" is similar to that of the pterygotid eurypterids and is a feature that "Slimonia" and the pterygotids only share with some derived hibbertopterid eurypterids (where the feature convergently evolved).The pterygotid telson was in general slightly larger than that of "Slimonia" and was more slender.The telson spike of "Slimonia" was much longer than any seen in the Pterygotidae (constituting just over half of the total telson length) however, serrated and ending in a fine point.