Late in Precambrian time
Silurian
The first mammals appeared during the Cretaceous Period.
the animals come on earth because god put them there
before time even started when mesopotamians were alive.
Animals have been around since the beginning of time. Jellyfish were one of the first living organisms that are made up of more than one cell. The first animal lived during the time of the dinosaurs, around the same time as the t-rex.
Scientists believe that animals evolved from single-celled organisms in the oceans around 600 million years ago, making them the first to appear. Plants, on the other hand, evolved from ancient algae and appeared on land around 450 million years ago.
Millions of years ago, possibly in the cretaceous period. None is entirely sure.
What year did the key first appear?
The first plants with spores, which indicates that they were land plants, appeared in the Middle Ordovician period, about 470 million years ago. First records of tetrapods, or land animals, show up in the fossil record around 370 million years ago.
Freckles are inherited. They first appear in childhood and if you are going to have them, they usually all appear by your 21st birthday.
Pascal's tiangle first appear in the year 1653.
Erm...skin is an organ, not an organism, first of all, and multicelled as well.