D?!? Let me know if you get it right
Answer:
The correct answer is option d. "a and b".
Explanation:
Plenty of methods had been developed to estimate the body size of dinosaurs such as the gigantic Sauropods. One of the first estimations that paleontologists used was the Archimedes principle, consisting in dunking the entire skeleton of a Sauropod into a pool of water and measure the water displacement or more precisely small dinosaur models. However this method requires the preservation of almost the entire skeleton. A more used and useful method is to measure the length of the legs from the hip to the foot and using a 2/3's power relationship convert that to a mass. This method is more used since it only requires a couple of leg bones, which are often well preserved.
1.Tyrannosaurus Rex Lived in the Mesozoic Era
2.The largest mass extinction happened in the Paleozoic Era
3.Life exploded for the first time in the Precambrian Era
4.The Chicxulub crater in the Cenozoic Era
Temporary changes would be weather, since it can change at any givin time another example would be tides coming in because they vary by day, or wet sand becoming dry sand!
