300 Foxes and a Donkey's Jawbone
Statements that the Earth had a uniform equable climate during geological periods are a little misleading. Sediments are assigned to periods based on their flora and fauna, to it's just a little microcosm of circular reasoning.
In real estate it's location, location, location. In Paleodoublespeak its location, location, location. Glossopterids didn't inhabit a savanna ecosystem with arid to semiarid climates, so there aren't any.
The Triassic wasn't rise of the cycadophytes and Ginkgoales, it's the preserved remains of cycadophytes and Ginkgoales because their habitat was destroyed and buried in a world-wide flood. That's Paleodoublespeak.
The Triassic is another microcosm of inductive reductive circular reasoning that we may wryly refer to as an "eddy in the space-time continuum." It's a tip of the hat to Douglas Adams, author of the Hitchhiker's Guide to the Galaxy.