Carcinosomatoidea is an extinct superfamily of eurypterids, an extinct group of cheliceratearthropods commonly known as "sea scorpions". It is one of the superfamilies classified as part of the suborder Eurypterina.
Some carcinosomatoid genera have been suggested to have been fully marine as opposed to living in near-shore brackish or hypersaline environments.[2]
The Carcinosomatoidea have a poorly resolved internal phylogeny, though can be easily recognised by scorpion-like appearance and heavily spinose appendages. Numerous characteristics support a close relationship to the Eurypteroidea.[2]