Newsademic British English edition 260

29th October 2015 
N e w s a d e m ic .co m ™
 - British English edition 
page 
17
these large herbivores by hunting 
them. Researchers, working at uni­
versities in the USA and UK, now 
think that they know why the Pleis­
tocene herbivores did not destroy 
the ecosystem. The answer, they 
say, is big cats.
A rtis t’s im pression o f a sabre-toothed cat
In the Pleistocene there were 
several big cat-like species. Ex­
amples are large lions, tigers and 
sabre-toothed cats. They were car­
nivores, or meat-eaters. Large hy­
enas were another type o f carnivore. 
The researchers studied the teeth 
o f these animals. From their teeth, 
they worked out body sizes. The 
researchers now think that these an­
cient cat-like creatures were at least 
50% bigger than modern-day tigers, 
African lions and hyenas. They also 
believe that these creatures worked 
together in large prides or packs. By 
doing this, the animals were able to 
successfully hunt and kill much big­
ger herbivores. If true, then these big 
cats (and hyenas) controlled mega­
fauna numbers. This, the researchers 
say, is why there was enough vegeta­
tion for smaller mammals and birds.
During the Pleistocene there 
were a number o f ice ages. Thick ice 
sheets covered large areas o f North 
America, northern Europe and Rus­
sia. The climate became drier, as 
much more water was ‘locked’ up 
in the ice. Many parts o f the world 
now covered by sea were dry land.
All the big cats and megafauna 
in the world (except for Africa) had
died out by the end o f the Pleisto­
cene. It is not known why. Some 
believe that the Earth’s climate be­
came much colder. Then, humans 
hunted any large herbivores that did 
survive to extinction. □
C