The estimate comes from studies of well-preserved T rex fossils – 32 of them, with enough material to determine they were adults.
Titanosaurs, thought to have been among the largest animals to walk the Earth, may have lived longer ago than previously thought.
Dinosaurs were not particularly diverse: there are only some 1,500 known species, compared to tens of thousands of modern mammalian and bird species.
Comet from solar system's edge triggered a winter that killed the dinosaurs 66 mn-years-ago: Harvard study
These long-period comets take about 200 years to orbit the Sun and we can expect similar impacts every 250 million to 750 million years.
It seems that crocodiles arrived at a body plan that was very efficient and versatile enough that they did not need to change or evolve in order to survive.
The reconstruction and analysis show that Earth's climate can be grouped into discrete states, based on changing greenhouse gas levels and growth of polar ice sheets.
The geologists believe that they might even find fossilised dinosaur eggs when they conduct a further excavation.
While birds, crocodilians and many dinosaurs laid hard-shelled eggs, the Antarctic egg had a soft, parchment-like shell.
Asteroid that killed dinosaurs hit Earth at 60 degrees, maximising the amount of climate-changing gases that entered the atmosphere
It released sulphur in the air and started a “nuclear winter” that not only wiped out dinosaurs but caused 75 percent of life on Earth to go extinct.
Asteroid, climate change is not responsible for the mass extinction that took place 215 million years ago
This mass extinction is termed as the Adamanian-Revueltian turnover, which saw a “decline in diversity among crocodylian-line archosaurs and the extinction of several taxa”.
During this period, there were mass extinctions, especially in oceans, caused by gases from the lava that flowed onto land.
Around 66 million years ago, a mass die-off called Cretaceous–Paleogene extinction event, put an end to the reign of dinosaurs.
Mammals had lived in the large shadow of the dinosaurs, never getting bigger than a small dog until the mass extinction.
Researchers based their theory by using thermal imaging to examine alligators in a Florida zoo.
The duck-billed dinosaur, that weighed almost as much as an Asian elephant, is believed to be a nine-year-old adult dinosaur.
The fossilized bird was found in a lump of amber and lived 99 million years ago in mangroves.
The Vespersaurus lived 90 million years ago and is in the same family as the Velociraptor.
The discovery is likely to fuel the debate over how birds & dinosaurs developed the ability to flap their wings.
The discovery gives researchers a peek into tyrannosaurs evolution before they took over the planet.
Humans are prove to be ultimate generalists owing more to technology than evolution.