Kirschvink evaded the real problem. Once the disparity exists, it is not difficult to explain the great diversity. We creationists explain the present diversity after the Flood based on basic animal kinds taken aboard the ark. Rapid diversification took place after the Flood when the animals returned to the land. Billions of dead things buried in rock layers laid down by water all over the earth.
Many evolutionists regard the Bible as myth and allegory.
Strange that after all these years, scientists who rejected catastrophe and embraced uniformitarian geology, sometimes for no better reason than to deny the Bible, are now embracing a catastrophic scenario to explain geology and evolution. This is strange because creationism teaches that the world's geological features and species diversification happened in a few thousand years. The difference is evolutionists believe these things took place in sudden spurts, each separated by millions of years. Creationists speculate that the Flood produced the fossil segregation patterns, e.g., trilobites in the Cambrian, dinosaurs in the Jurassic, etc. Evolutionists note five major periods of mass extinction in the fossil record.