What term is used for the group of similar organisms within a classification that is one rank below Class?

The term used for the group of similar organisms within a classification that is one rank below Class is "Order." In biological classification, the hierarchy is structured as follows: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. Therefore, Order sits directly beneath Class in this system.

For context, while Phylum is a broader category that encompasses multiple Classes, Family and Genus are categories that are more specific and fall beneath Order in the classification hierarchy. This helps in organizing living organisms based on their evolutionary relationships and characteristics, allowing scientists to communicate effectively about biodiversity.