Animals have achieved greater diversification than plants due to reasons :
(i)
They have nervous system to receive stimuli and respond against them
Most of their responses are adaptive for their survival in changing
environment.
(ii) They are mobile and to avoid competition. They show niche specialization.
(iii)
They are subjected to less seasonal and more constant environment.
Plants are fixed and require fewer evolutionary adaptations in order to
obtain their requirement of water, minerals and sunlight or avoid
destruction due to excessive herbivory. All this has resulted in higher
species diversity among animals than plants.