Question

how the methods of animal classification changed over the time? Short answer

Answer 1

These organisms didn't fit into theclassification system of the time. The system had to be changed to incorporate this new group or organisms. ... Changes to theclassification system have meant that the classification of some species of organisms has changed too.

HOPE IT HELPS

Answer 2

The answer is that the criteria of classification change with the improved understanding of organisms around us. During the time of Aristotle, not much was known about the living organisms. So, he classified them as he observed. Plants were classified into herbs, shrubs and trees; very much like what’s taught to a second grade student. Animals as Enaima and Anaima based on the presence or absence of RBCs. After him, Carolus Linnaeus tried his hand over classification. He came up with the 2 kingdom classification: Plants and Animals. He considered only a set of morphological and physiological criteria to decide the kingdom to which an organism belongs. It includes presence of cell wall, mode of nutrition, contractile vacuole, locomotion and others. Based on these criteria, he included widely differing organisms into a single kingdom, for example, fungi, bacteria, algae, and higher plants were included into plant kingdom just because they have cell wall as a common aspect.

Our understanding of organisms around us is improving day by day and the system of classification will also change further in pace with the improvement in technology.

HOPE IT HELPS :-)