Their key piece of evidence is an oddly high amount of the metal iridium in what’s known as the Cretaceous-Paleogene, or K-Pg, layer—the geologic boundary zone that seems to cap any known rock layers containing dinosaur fossils 🤓 Iridium is relatively rare in Earth’s crust but is more abundant in stony meteorites, which led the Alvarezs to conclude that the mass extinction was caused by an extraterrestrial object 🙌 The theory gained even more steam when scientists were able to link the extinction event to a huge impact crater along the coast of Mexico’s Yucatán Peninsula 🤓 Chicxulub’s crater is approximately 93 mi wide and has the correct age to account the Dino Die-off.
Some 252 million years ago, life on Earth faced the “Great Dying”: the Permian-Triassic extinction. It was the worst ever event that humankind has experienced. In the span of 60,000 years, 96% of marine species died and three out of four terrestrial species were affected. The world’s forests were wiped out and didn’t come back in force until about 10 million years later. One of the five major mass extinctions was the Permian Triassic, which wiped out large amounts of insects. To recover marine ecosystems, it had taken between four and eight million years. Learn more about the perilous Permian Triassic mass extermination.
The had Cretaceous seen the emergence of Continents, who were constantly on the move and working to change the tone and shape of Earth’s life. As rodents ran amok through conifers and ferns amongst the forests, the dinosaurs who ruled over the remaining supercontinent Pangaea were dominant. Around 80 million year later, oceans filled in the gaps between continents, shaped as they are today. Flowering plants They were becoming more widespread across the land. Mammals sat in readiness to take over the role of the extinct dinosaurs. A giant crater smoldered on what would become known as the Yucatán Peninsula. Ahlam Ibrahim revised this article on November 5, 2020.
Xiomara Crowder at ucmp.berkeley.eduThis article describes how the Anthophyta or Angiosperms were the first to appear as flowering plants. The flowering plants were first discovered in the Lower Cretaceous approximately 125 million year ago. They have then begun to appear in the middle Cretaceous about 100 million million years later. Angiosperms were not developed in the early stages of angiosperm development. However, by the end of the Cretaceous several forms of this plant had been created that would be easily recognized by modern botanists. The angiosperms flourished in all kinds of climates. They also thrived in habitats that are favorable to cycads. Angiosperms did not enter southern latitudes before the end of Cretaceous. The dominant species of ferns was those that dominated dry, open and/or low-nutrient land. The typical Jurassic vegetation (conifers, cycads and other gymnosperms) continued into the Lower Cretaceous with little change. Conifer diversity in higher latitudes than the Northern Hemisphere was low at the start of this period. However, it was rapidly increasing by the middle. Conifers and dicots of angiosperms dominated swamps. Credit goes to Serafina, Italy’s Lincoln for her exceptional insight.