Here's why:
* Kingdoms are a broad taxonomic rank. While classifying organisms into kingdoms is a key part of biology, it's not a specific focus like, for example, "taxonomist" who studies classification in general.
* The concept of kingdoms has evolved. Historically, five kingdoms were common (animals, plants, fungi, protists, and monera). Now, scientists generally use three domains (Archaea, Bacteria, and Eukarya) with further classification within each.
Instead of a specific title, you could describe someone who classifies things into kingdoms as:
* A biologist: This is a general term for someone who studies living things, including their classification.
* A taxonomist: This term refers to someone who studies the classification of organisms.
* A scientist specializing in phylogeny: This refers to someone who studies the evolutionary relationships between organisms, which is closely linked to classification.
Ultimately, the most accurate description would depend on the specific context and the person's area of expertise.
