No land animals (vertebrates) existed 440 million years ago. Lots of sea life, though. Bugs also started to appear about that time. Some scientists speculate a hypernova explosion may have caused a mass extinction of most of the life on Earth 440 million years ago.
Centipedes appeared around 420 million years ago, they are one of the first terrestrial animals.
about 420 million years ago
To write 420 million in numbers, you start with the numeral 420 and add six zeros to represent the millions. Therefore, 420 million is written as 420,000,000.
420 million can be written as 420,000,000 in digits.
420 million years ago
Your answer is only about the name, so no. The mountain is 420 million years old
thay were around when there were dinosrs
100 years = 1 century so 420 years = 4.2 centuries.
$420 million
4 420 000
$420 million
Bony fish first appeared on Earth around 420 million years ago during the Silurian period. They evolved from earlier jawless fish and quickly diversified into various forms, becoming one of the most successful groups of vertebrates in the oceans.