Mineral crisis as evolutionary driver: the Carnian Pluvial Episode, mammalian orotate-mediated magnesium transport, and lithium orotate as a contemporary footprint

We propose that a coordinated transport infrastructure present in modern mammals — comprising the SLC2A9 (GLUT9) facilitative transporter and the SLC22A12 (URAT1) organic anion exchanger — arose during the Carnian Pluvial Episode (~234-232 Ma) under selection for maternal magnesium delivery to offspring, and that the same infrastructure accounts for the distinctive pharmacokinetics of lithium orotate observed in modern mammals.