Learning with Granny!
Prehistoric Facts
After the visit to the science festival and all the
excitement of 'The First African in Space', Granny carries on with her story of TIME...
(you can catch up on the story if you visit the links to the left)
"There are not many stars out tonight, please
would you carry on and tell us about what happened on Earth after the dinosaurs
became extinct" asked Terry.
Granny had her 'Time chart' in front of her. It was
proving most useful in explaining this difficult subject to the children - but
even she found the huge time span hard to grasp. She pointed to the tiny bit
still to do before reaching the present time on Earth.
'The next era is the Cenozoic Era' she began 'and is
called 'the Age of Mammals' - it started 65 million years ago and is divided
into two periods - The Tertiary and The Quaternary.
The Tertiary period is divided into five shorter
periods - the first being The Paleacene Epoch - from 65 to 54 million years ago.
At this time the weather was warm and moist. India, Asia and Europe had not
joined yet. Australia was still part of Antarctica, and North America was
attached to Europe in the North. Although big animals like dinosaurs had
disappeared, there were lots of mammals, rodents , primates (early monkeys) and
large flying birds. Flowering plants were doing well and new species were
developing all the time. In the  sea,
sharks were surviving and so were many types of creatures with shells and all
sorts of fish.' Granny continued as everyone listened 'The second period in the
Tertiary Period of the Cenozoic Era is the Eocene Epoch from 54 to 38 million
years ago. North America separated from Europe..' (click
on the image to the right to see the shifting continents).
'The movement of the continents caused the Pyrenees Mountains to rise. This
range of mountains is between France and Spain.
Lee interupted 'The Fleas that tease in the high Pyrenees' he quoted from
Hilaire Belloc's poem Tarentella. 'That's right said Granny. Remind me to tell
you about the wonderful ice age artifacts from the caves there when we get to
that point in time, but lets get back to the Eocene epoch.
There were whales in the sea all round the world and an
early type of horse made its appearance on land - much smaller than the ones we
have now. There were rodents, bats, elephants and lemurs with pointed snouts and
long tails.
During the next period, the
Oligocene Epoch from 38 to 26 million years ago, Australia finally 'cut its
ties' with Antarctia. India  collided
with Asia - forcing the edges of the land up into a huge mountain range called
the Himalayas. The weather got cooler. Grass and trees covered the land and
there were many early types of grazing animals. Also dogs, rats, pigs, and giant
sloths. Granny stopped for a break to look at a picture of some prehistoric
animals. (Click on the image to the right...)
In the fourth period - The Miocene period from 26 to 7
million years ags, Africa moved up to Europe. This formed The Alps. Sea levels
were low because water was frozen in ice sheets in Antartica. Sabre-tooth
cats/tigers as well as monkeys and apes were about. Elephants started to leave
Africa and go to Eurasia. Cats, cattle, giraffe and pigs moved about too. There
was plenty of grass on all the continents for the animals and marsupials could
be found in Australia'
'Granny what's a marsupial?' asked Terry 'I know a kangaroo is one - but I'm not
sure why'. 'I know' said Lee 'can I tell her?' 'Sure - go ahead' pleased that
someone else could do the talking. 'It's a mammal that's born before its ready
to live outside the mother, so it goes into a special pouch where it feeds from
the mother and is protected until it's fully developed and can come out.' he
concluded. 'We saw them at the zoo' said Margie sitting up straight to deliver
her piece.
'The Pliocene Epoch is the last of the Tertiary period
-from 7 million to 2 million years ago. By this time all the continents were in
the positions they are in now. North and South America were joined - so sea life
between the Atlantic and the Pacific oceans could no longer mix as easily. An
ice sheet appeared in the Arctic predicting the forthcoming Ice Age. The weather
was getting cooler.
Most mammals we know today were about. Rats arrived in Australia and, what are
believed to be human ancestors, appeared in Africa' Granny stopped when Lee
repeated 'Human ancestors appeared in Africa?' 'Yes, answered Granny,
scientists, anthropologists, paleoanthropologists - most people who study the
early inhabitants of Earth -sincerely believe that Africa is where human life
began - they call it 'the Cradle of Humanity'.
'Now I feel as if I am learning things I've always
wanted to know - wow this is getting interesting' said Vinny, moving up closer
to the book Granny had open on her lap.
'Show them this picture of the man digging up the big
fossil Gran' he went on turning the book around. 'That's
like the man we saw at the  science
festival' cried Ann excitedly. 'I remember that - I didn't like the
noise of the little electric drill he used' said Margie. 'That was very
interesting' remarked Lee 'he had to do it so carefully and slowly so as not to
damage the fossil buried in the rock. (click on the image to the right...)
Going back to what Vinny said about learning -
education is not just learning to read and write, it's also what you get from
mixing with people of different races and from different parts of the world and
seeing how they live, hearing them talk about what they know and think and
trying to understand their background, their history and their beliefs.
Granny went on 'What we are talking and learning about, can all be read in lots
of detail in wonderful books from the library. If you find it interesting, you
must go and read up on the subjects in more detail.'
'Don't think that people started walking about in
Africa at this time' went on Granny going back to the story 'The fossil remains
of these early manlike creatures did, however, show a slight 'breakaway' from
the line of apes - gorillas and chimpanzees. About 7 million years ago, some of
these ape-like creatures began to walk upright. By doing this they were able to
change their way of gathering food. The position of their bones changed, they
developed muscles in different places and their internal organs altered. They
were called Primates. Their ancestors were the size of a mouse and lived in
trees and ate fruit, insects and bird's eggs.
Much later they developed long fingers and toes to help
them cling to twigs and branches. Their eyes faced the front so they could see
better as they leapt fom tree to tree. We call these creatures Pro simians
(meaning before the simians or apes).
By the Pliocene Epoch, ape like animals lived in the trees in Europe, India and
Africa. Their faces were flat with human-like teeth and jaw. They were called Ramapithecus
and they might have been an ancestor of humans.
Three million years ago, much of the forests died out due to the weather
becoming drier. The ground was open and an ape called Australopithecus
was seen. One of the first was called Australopithecus afarensis.'
Turning to Lee, who had raised his eyebrows Granny said
'Don't worry about the long names - they are on the chart and you will get used
to seeing them later when you've heard them more often and know the meanings'.
'It's like the dinosaurs' said Vinny 'you always say them wrong and we have to
tell you how to pronounce them'. 'That's right - when you are interested in a
subject, you really make an effort to learn it correctly. Now let's go on'.
'This little 'A afarensis' was no bigger than a monkey like we see down
near the dam. He could walk upright and had a big brain. He could use his hands
for doing lots of things now that they were not needed for running and climbing.
Australopithecus split at this time into two groups. The first 'A robustus'
ate just seeds and nuts - this gorilla-like ape has stayed much the same until
today.
The second called 'A africanus' ate meat and
plants and hunted in groups, guarding their kill from intruders. This behaviour
showed the first signs of belonging to a group and doing things, not just for
themselves, but to benefit others.' Granny stood up and stretched 'Now I think
its time for this group to march off to bed'.
'Margie won't be doing any marching - she's fast asleep' said Terry.
Fossils in Focus
Studying fossils can be great fun
You'll find out about life since time begun.
Great big dinosaurs - long gone from Earth
Pre-historic mammals that first gave birth.
--------
Discover that eggs held lots of strange things
Before one revealed a creature with wings.
Read of huge great flightless birds
And grazing animals that moved in herds.
--------
Of an early horse - no bigger than a dog
And the value to the world of a slimy frog.
You will find many reasons to debate
Why early animals chose to migrate.
--------
You'll learn how evidence can be seen
Of human ancestors on the fossil scene
Then you'll go on to read of Early Men
As we forge on ahead and meet Homo sapien
--------
Jenny Marais 2002
Interesting books that Granny Jenny can recommend
are:-
1) 'Prehistoric Animals' by Rupert Matthews. pub. by
Pick 'n Pay.
2) 'Prehistoric Life - Questions and Answers' by Juri van den Heever pub. New
Holland.
3) 'Prehistoric Life and Evolution' By Dougal Dixon. pub by Prentice Hall.
4) 'The Practical Fossil Finder' by Steve Parker. pub by Fact On File.
Go back to Granny's 'Birth
of Earth' chart at
to look at the overall picture to see how far we have come/travelled..
If you would like to e-mail Granny
your questions and ideas please do so at granny@scienceinafrica.co.za
Until Next Month, Happy Reading!
Granny Jenny
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