The animal kingdom is divided into about 30 phyla. The nine largest phyla contain the majority of species.
One phyla, the arthropods, which includes insects and spiders, constitutes about 75 percent of all known animal species. More than 900,000 arthropods have been described, and according to some estimates there may be more than five million more.
The number of known species for all animals other than arthropods is about 250,000.
The largest group within the phyla of arthropods and the most diverse class in all kingdoms, is insects. Over 750,000 have been described. Some suppose that there are perhaps as many as three million different species of insects in the world.
The most diverse family of insect is beetles, with over 375,000 types identified.
Other large families of insects include butterflies and moths (more than 100,000 species), bees and wasps (more than 20,000 species), and ants (about 10,000 species).
With over 30,000 known species, spiders, which are not insects, constitute one of the large families of other kinds of arthropods.
Only two other phyla within the animal kingdom, the roundworms and the mollusks, are known to contain more than 100,000 species. All other phyla generally have far less.
The dominant phyla on the planet, the vertebrates, consists of less than 50,000 known species. The number of fish species is estimated to be more than 20,000, bird species number approximately 8,700, reptiles about 6,000, mammals about 4,500, and amphibians about 2,500.
Within mammals, the rodents are the most varied order, with 34 families and more than 1,700 species.
How many species are known to currently exist in the world.
|Spiders and scorpions||102,248|
|Flowering plants (angiosperms)||281,821|
|Ferns and horsetails||12,000|
|Red and green algae||10,134|