"Many genera of angiosperms became extinct". Their habitat got buried in a world-wide flood. The deposits were subsequently buried so deep that there was no way for the seeds to germinate and reach sunlight.
Angiosperm Mass Extinction
Magnoliaceae, Lauraceae and Juglandaceae
"Angiosperms having affinities with Magnoliaceae, Lauraceae, Juglandaceae". This may seem random but it's nuanced evolution narrative, you just have to know something about the development of Angiosperms.
Angiosperms Rise to Dominance
This is narrative that's designed to establish the evolution premise that the Angiosperms are the most developmentally advanced kinds of plants, and so therefore have the most recent origin.
Heterospory and the Seed Habit
"Heterospory and the seed habit" is scientific smoke and mirrors. It sounds technical, so most folk will probably assume that so long as someone else understands it, then everything's okay.
Diversification of Vascular Plants
"Diversification of vascular plants: all major groups except flowering plants present by end of Devonian". This demonstrates how inductive reasoning is used to account for evidence.