Short answers, pulled from the story.
The most complete Tyrannosaurus specimens measured between 12.3 and 12.8 meters in length and stood 3.66 to 3.96 meters tall at the hips. A specimen nicknamed Scotty, located at the Royal Saskatchewan Museum, measured 13 meters in length and was estimated at 8.87 metric tons in body mass, making it the largest known individual.
Barnum Brown, assistant curator of the American Museum of Natural History, found the first partial T. rex skeleton in eastern Wyoming in 1900. He found a second, larger skeleton in the Hell Creek Formation of Montana in 1902. Henry Fairfield Osborn, president of the American Museum, formally named the species Tyrannosaurus rex in 1905.
The Field Museum of Natural History purchased Sue at auction in 1997 for $7.6 million, at the time the most expensive dinosaur skeleton ever sold. That record was later surpassed in 2020 when another specimen, nicknamed Stan, sold for $31.8 million.
Most current evidence points toward an endothermic metabolism similar to modern birds. A 2022 study by Wiemann and colleagues used spectroscopy of lipoxidation signals to show that Tyrannosaurus had a warm-blooded metabolism on par with modern birds and higher than that of mammals. Earlier histological evidence of rapid growth rates in young T. rex, comparable to those of birds and mammals, also supports a high metabolism.
Most paleontologists today accept that Tyrannosaurus was both a predator and a scavenger. As the largest carnivore in its environment, it most likely preyed upon hadrosaurs, juvenile ceratopsians, juvenile ankylosaurs, and possibly sauropods. The question of whether it was primarily a predator or a pure scavenger was one of the longest debates in paleontology.
Speed estimates for T. rex have ranged from roughly 4.5-6.8 m/s to as high as 20 m/s, though the higher end is considered very unlikely. A 2002 study found that speeds above 40 km/h would have required leg muscles making up 40-86% of total body mass. A 2021 study calculated a preferred walking speed of 1.28 m/s based on how the tail swayed during locomotion.