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.
An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the amount of life on Earth.Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. This extinction event lasted perhaps as long as 20 million years, and there is evidence for a series of extinction pulses within this period. 2  OrdovicianâSilurian extinction events (End Ordovician or O-S): 450â440 Ma at the Ordovician-Silurian transition.