■ Around 542 million BC Cambrian explosion

Multicellular animals have emerged explosively. Animals before this are small and less likely to remain as fossils and are less likely to be found. Before the Cambrian explosion, it rapidly grew in size and remained as a fossil.

●●●●●●●
References

Biological evolution from the viewpoint of molecules History of organisms revealed by DNA / Takashi
Miyata The story of Takashi Miyata's evolution (figure only)