Sedgwick, however, never accepted Darwin's theory of evolution and natural selection. For example, during most of Cambrian, sea level was so high that an epicontinental sea covered North America except for a series of low islands running southwest-northeast along the elevated middle part of the continent i.
Another type of sponge looked like an ice cream cone-without the ice cream, of course! During its separation from the main Gondwana land mass, Laurentia had a collision with the southern end of what is now South America specifically western Argentinawhich resulted in some crustal deformation and mountain building.
The melting of the Varanger glaciers during the Neoproterozoic also played a role in the flooding of continents. Sponges Sponges grew in Cambrian seas, too. During Cambrian, the breakup of the supercontinent of Gondwana began with the separation of some landmasses including part of Asia and the ancient continents called Baltica and Laurentia i.
Cambrian Explosion Nevertheless, the scale of the Cambrian Explosion is likely exaggerated due to the proliferation of hard-bodied animals that fossilized much more readily than their soft-bodied precursors. You wouldn't have known it to visit the earth's oceans million years ago, but vertebrates, and not invertebrates, were destined to become the dominant animals on the planet, at least in terms of body mass and intelligence.