1 Dry mouth can be a side effect of medical conditions, including SjÃ¶gren's syndrome, HIV/AIDS, Alzheimer's disease, diabetes, anemia, cystic fibrosis, rheumatoid arthritis, hypertension, Parkinson's disease, stroke, and mumps.  Side effect of certain medical treatments.
View full size image. The Cretaceous Period was the last and longest segment of the Mesozoic Era. It lasted approximately 79 million years, from the minor extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous-Paleogene (K-Pg) extinction event dated at 65.5 million years ago.In the early Cretaceous, the continents were in very different positions than they are today.iew full size image. The Cretaceous Period was the last and longest segment of the Mesozoic Era. It lasted approximately 79 million years, from the minor extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous-Paleogene (K-Pg) extinction event dated at 65.5 million years ago.
3. PermianâTriassic extinction event (End Permian): This one occurred right about 251 million years ago. It is the largest extinction event that is currently known. It led to the extinction of â57% of all families, 83% of all genera and 90% to 96% of all species.rdovicianâSilurian extinction event (End Ordovician): It occurred about 450â440 million years ago. It actually consisted of two different events, in total they annihilated 27% of all families, 57% of all genera and 60% to 70% of all known species.