"Since life began on Earth, several major mass extinctions have significantly exceeded the background extinction rate. The most recent, the Cretaceous–Paleogene extinction event, which occurred approximately 66 million years ago (Ma), was a large-scale mass extinction of animal and plant species in a geologically short period of time."
....just what I said, Dinosaurs! What's to disagree about? Just about every thing else was the result of mismanagement of the environment!
You are so intellectually dishonest. No one could have possibly read that web sight and reached that conclusion.
Cretaceous–Paleogene extinction event (End Cretaceous, K-T extinction, or K-Pg extinction): 66 Ma at the Cretaceous.Maastrichtian-Paleogene.Danian transition interval.[5] The K–T event is now officially called the Cretaceous–Paleogene (or K–Pg) extinction event in place of Cretaceous-Tertiary. About 17% of all families, 50% of all genera[6] and 75% of all species became extinct.[7] In the seas it reduced the percentage of sessile animals to about 33%. All non-avian dinosaurs became extinct during that time.[8] The boundary event was severe with a significant amount of variability in the rate of extinction between and among different clades. Mammals and birds emerged as dominant land vertebrates in the age of new life.
Triassic–Jurassic extinction event (End Triassic): 200 Ma at the Triassic-Jurassic transition. About 23% of all families, 48% of all genera (20% of marine families and 55% of marine genera) and 70% to 75% of all species went extinct.[6] Most non-dinosaurian archosaurs, most therapsids, and most of the large amphibians were eliminated, leaving dinosaurs with little terrestrial competition. Non-dinosaurian archosaurs continued to dominate aquatic environments, while non-archosaurian diapsids continued to dominate marine environments. The Temnospondyl lineage of large amphibians also survived until the Cretaceous in Australia (e.g., Koolasuchus).
Permian–Triassic extinction event (End Permian): 251 Ma at the Permian-Triassic transition. Earth's largest extinction killed 57% of all families, 83% of all genera and 90% to 96% of all species[6] (53% of marine families, 84% of marine genera, about 96% of all marine species and an estimated 70% of land species, including insects).[9] The evidence of plants is less clear, but new taxa became dominant after the extinction.[10] The "Great Dying" had enormous evolutionary significance: on land, it ended the primacy of mammal-like reptiles. The recovery of vertebrates took 30 million years,[11] but the vacant niches created the opportunity for archosaurs to become ascendant. In the seas, the percentage of animals that were sessile dropped from 67% to 50%. The whole late Permian was a difficult time for at least marine life, even before the "Great Dying".
Late Devonian extinction: 375–360 Ma near the Devonian-Carboniferous transition. At the end of the Frasnian Age in the later part(s) of the Devonian Period, a prolonged series of extinctions eliminated about 19% of all families, 50% of all genera[6] and 70% of all species.[citation needed] This extinction event lasted perhaps as long as 20 Ma, and there is evidence for a series of extinction pulses within this period.
Ordovician–Silurian extinction event (End Ordovician or O-S): 450–440 Ma at the Ordovician-Silurian transition. Two events occurred that killed off 27% of all families, 57% of all genera and 60% to 70% of all species.[6] Together they are ranked by many scientists as the second largest of the five major extinctions in Earth's history in terms of percentage of genera that went extinct.
