How useful is the study of the nature of body cavity and coelom in the classification of animals?

The nature of body cavity and coelom is essential in classification because it influences organ development, physiological complexity, and evolutionary advancement; acoelomates lack a body cavity, pseudocoelomates have an unlined body cavity, and true coelomates possess a cavity fully lined with mesoderm, enabling the development of complex organ systems, efficient nutrient transport, and effective locomotion, thus making coelom type a key feature in differentiating major animal groups.