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While dinosaurs were ancestrally bipedal, ... at about 215 million years ago, ... some of the longest were the 33.5-meter (110 ft) long Diplodocus hallorum ...
End Triassic: 200 million years ago, 80% of species lost, including all conodonts; End Cretaceous: 66 million years ago, 76% of species lost, including all ammonites, mosasaurs, plesiosaurs, pterosaurs, and nonavian dinosaurs; Smaller extinction events have occurred in the periods between, with some dividing geologic time periods and epochs.
In this scenario, terrestrial and marine communities were stressed by the changes in, and loss of, habitats. Dinosaurs, as the largest vertebrates, were the first affected by environmental changes, and their diversity declined. At the same time, particulate materials from volcanism cooled and dried areas of the globe. Then an impact event ...
The Mesozoic Era [3] is the era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods.It is characterized by the dominance of gymnosperms such as cycads, ginkgoaceae and araucarian conifers, and of archosaurian reptiles such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea.
Birds were therefore the only dinosaur lineage to survive the Cretaceous–Paleogene extinction event approximately 66 million years ago. Dinosaurs can be divided into avian dinosaurs (birds) and non-avian dinosaurs, which are all dinosaurs other than birds. Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs.
The earliest dinosaurs were unremarkable, bit players on a supercontinent crowded with other ancient reptiles when they first evolved around 230 million years ago.
Early long-tailed pterosaurs appeared in the Norian and quickly spread worldwide. Triassic dinosaurs evolved in the Carnian and include early sauropodomorphs and theropods. Most Triassic dinosaurs were small predators and only a few were common, such as Coelophysis, which was 1 to 2 metres (3.3 to 6.6 ft
An international team found dinosaurs had been evolving and expanding, but showed a sudden downturn around 76 million years ago. Dinosaurs were in decline up to 10 million years before asteroid ...