The Cretaceous-Tertiary extinction event, or the K-T event, is the name given to the die-off of the dinosaurs and other species that took place some 65.5 million years ago. For many years, paleontologists believed this event was caused by climate and geological changes that interrupted the dinosaurs’ food supply. However, in the 1980s, father-and-son scientists Luis (1911-88) and Walter Alvarez (1940-) discovered in the geological record a distinct layer of iridium–an element found in abundance only in space–that corresponds to the precise time the dinosaurs died. This suggests that a comet, asteroid or meteor impact event may have caused the extinction of the dinosaurs. In the 1990s, scientists located the massive Chicxulub Crater at the tip of Mexico’s Yucatán Peninsula, which dates to the period in question.
Dinosaurs roamed the earth for 160 million years until their sudden demise some 65.5 million years ago, in an event now known as the Cretaceous-Tertiary, or K-T, extinction event. (“K” is the abbreviation for Cretaceous, which is associated with the German word “Kreidezeit.”) Besides dinosaurs, many other species of mammals, amphibians and plants died out at the same time. Over the years, paleontologists have proposed several theories for this extensive die-off. One early theory was that small mammals ate dinosaur eggs, thereby reducing the dinosaur population until it became unsustainable. Another theory was that dinosaurs’ bodies became too big to be operated by their small brains. Some scientists believed a great plague decimated the dinosaur population and then spread to the animals that feasted on their carcasses. Starvation was another possibility: Large dinosaurs required vast amounts of food and could have stripped bare all the vegetation in their habitat. But many of these theories are easily dismissed. If dinosaurs’ brains were too small to be adaptive, they would not have flourished for 160 million years. Also, plants do not have brains nor do they suffer from the same diseases as animals, so their simultaneous extinction makes these theories less plausible.
Answer:
Nubian traders supplied Egypt with animal skins, ivory, ostrich feathers, and beautiful woods from the African interior. Nubia traded gold from its desert mines for Egyptian wheat.
#3 is Martin Luther King Jr. and Robert F. Kennedy. As a result, they left the nation in political turmoil.
The result is not unusual since the probability that p is
equal to or more extreme than the sample proportion is greater than 5% (153/300
= 0.51). Thus, it is not unusual for a wrong call to be made in an election if
exit polling alone is considered.
Answer:
caviling at
Explanation:
The word "caviling" means making unnecessary objections or complaints. In order words it means to raise trivial and irritating objections.
In the context, hardly anyone blamed others for their deeds. But Thaddeus astonished his coworkers or colleagues when he began to cavil at or make objection at their most unimportant mistakes.
Hence the answer is -- "caviling at".
