"Short-finned" is a term commonly used in the scientific name of certain aquatic animals. However, if you're looking for synonyms for this phrase, you can consider using words like abbreviated, truncated, stunted, or miniaturized. Each term conveys the idea of something being shorter than usual, but with a slightly different connotation. "Abbreviated," for example, suggests a shortening that has been intentional or planned, while "stunted" implies a development that has been hindered or limited. Ultimately, the synonym you choose may depend on the specific context in which you are using it.