Many of the animals began to die off and became extinct.
paleozoic
Apparently the world heated up and many genera died off.
If you mean animals as in insects (arthropods), they came in around the Devonian period of the Paleozoic era If you mean animals as in fish, amphibians etc then they came in at the same time as the arthropods
The Paleozoic era was an age where Earth's diversity is believed to have greatly multiplied, with ocean animals coming out onto land. Massive forests with primitive plants dominated the earth's surface and dinosaurs possibly roamed around. The Paleozoic era ended with a mass extinction of many of these organisms and life on land was slow to recover.
The one mass of land known as Pangaea was formed In the Era Paleozoic, along with mountains, and land breathing animals.
Plants and animals first reached land during the Silurian period, which is part of the Paleozoic era. This occurred approximately 420 million years ago. These early land organisms played a crucial role in shaping terrestrial ecosystems and paving the way for future life on land.
The colonization of land by plants did not occur during the Cenozoic era as it happened earlier during the Paleozoic era.
Land based animals first became common in the Paleozoic Era. It is the earliest era of the 3 in the Phanerozoic Eon.
The changing geologic condition of the Paleozoic age affected the evolution of animals by leading to the development of land based vertebrates and vascular plants. The largest mass extinction in our planets history happen at the end of the Paleozoic Era.
They had little competition from other land dwellers
During the Paleozoic era, many land and sea animals experienced significant evolutionary changes and diversification. The era saw the emergence of early fish, amphibians, and reptiles, as well as the development of extensive marine ecosystems. However, it ended with the Permian-Triassic extinction event, the largest mass extinction in Earth's history, which wiped out around 90% of marine species and a significant number of terrestrial organisms. This extinction dramatically reshaped the biological landscape and set the stage for the Mesozoic era.
The second era in geological time is the Paleozoic era, which lasted from about 541 million years ago to 252 million years ago. It is known for the evolution of early marine life, the colonization of land by plants and animals, and the formation of the supercontinent Pangaea. Major events during this era include the Cambrian explosion, the colonization of land by plants during the Silurian period, and the mass extinction at the end of the Permian period.