Because nobody has found them or seen them yet
no... there are species still being discovered today
No way. There are over 25 million more species to be discovered.
1.4 million species have been identified so far.
Oxygen was discovered by the very first species on planet Earth.
4000 species known, but over 3million presumed to be living on the earth 4000 species known, but over 3million presumed to be living on the earth
Unknown. They discovered some new species only last month.
There are 800 000 identified species, most of which are insects and invertebrates. However, many new species are continually being discovered, and taking into account the huge areas still unexplored on Earth (eg forests in South America, small islands, and most oceans), the true number of animal species on earth is probably far larger.
Tiger seasons and lime salt
There really isn't a date the Earth was discovered, as humans have known of the existence of the planet since the species was first capable of symbolic thought.
No. Far from it. (An enthusiastic 'ditto')
About 1.2 million===========================There are about 8 million animal species.Just under 2 million different Animals have been described but the real number as estimated to be around about 5 million. Most of the animals on Earth (97%) are invertebrates like Jellyfish, Insects and Arachnids the rest are vertebrates like Amphibians, Fish, Reptiles, Mammals and Birds.About 1,250,000 identified species of animal.Estimates of the total number of species of animals on Earth range from 2 to 30 million.There are between 10 million and 1 billion species of bacteria and archaea.So far, a few million different species have been identified, and the number is growing daily. Estimates for the total number of species on Earth (discovered or otherwise) vary from 10 million to 100 million. Most of the known species (and most likely Kingdom Animalia) are various beetles. Already we have found hundreds of thousands of beetles.
Earth's moon would have been the first moon discovered. Galileo observations identified four of Jupiter's moons - Io, Europa, Ganymede, Callisto - in 1610.
He did not need to discover that as it was already known by the ancient Greeks.