Question

Which of the following is the most species-rich taxonomic group among animals?

• A. Mammalia
• B. Insecta
• C. Reptilia
• D. Aves

Answer 1

The correct option is B Insecta

According to the reports by the International Union for Conservation of Nature (2004), more than 1.5 million species of plants and animals have been identified and described by biologists so far.

But the estimates made by Robert May state that only 22% of the existing species on Earth have been described so far and the rest are yet to be identified.

The currently available records on the identified species tells us that more than 70% of all the recorded species are animals and amongst animals, more than 70% of the species belong to the class Insecta. This indicates that out of every 10 animal species on this planet, 7 are insects. This makes the insects the most species-rich taxonomic group.

If we classify the animals into vertebrates and invertebrates, then insects show maximum species diversity amongst invertebrates and fishes (Pisces) show maximum diversity amongst vertebrates, followed by birds (Aves), reptiles (class Reptilia) and mammals (class Mammalia).

But the species diversity of insects is collectively more than all other taxonomic groups in the animal kingdom.