Cambrian period

Geochronological data;
Eon: Phanerozoic.
Era: Paleozoic.
Climate;
Oxygen level: 21%
CO2 level: 7-9%
Average temperature: 25 °C.
You appeared in the Cambrian period. There is nothing on land, not even plants.
Overall, the climate was warm and equable, with little temperature difference between the equator and the poles. High levels of carbon dioxide in the atmosphere contributed to the greenhouse effect.
The ocean looked crystal clear, bluish-green.

Living organisms (Small part):
Trilobites are one of the most prominent groups of arthropods, closely related to crustaceans. They reached their peak in the Cambrian.
During this period, everyone was not intelligent and could not speak.
Archaeocyathids are sponge-like animals with a porous calcareous skeleton. They built early reefs.
Brachiopods (resembling bivalves in appearance, but belonging to a different group) - in the Cambrian, inarticulate forms predominated.
Mollusks - at the beginning of the period there were monoplacophorans and gastropods, in the middle - bivalves, in the late period - cephalopods (nautiloids were just beginning to form).
Radiodonts (such as Anomalocaris) were large swimming animals that included predators, gatherers, and filter feeders.
Opabinia (with five eyes and a long proboscis), Hallucigenia (with spines and thin limbs).
Early chordates—for example, Haikouichthys and Pikaia—show early chordate characteristics. Some forms (such as Myllocunmingia) are considered among the oldest vertebrates or their close relatives.
Plants are mainly algae (blue-green, green, red).
Annelids (annelids) - their ancient representatives, such as Zhangjiagoivermis, already had a segmented body and paired limbs.
Priapulids were marine worms that burrowed into the sand and filtered plankton.
Ostracods are crustaceans with a calcareous shell.
Priapulids are marine worms that have remained virtually unchanged since the Cambrian period.
Radiodonts were large swimming predators, such as Anomalocaris, that possessed grasping appendages.
Vaptiya is an arthropod with a bivalve carapace and a swimming abdomen.
During the Cambrian period, days lasted approximately 20.5 hours. Even at night, the water remained warm.