Learning with Granny!
The Dinosaurs At Last!
We hope you are still with us as Granny and the children continue on the next
leg of their 'Journey through Time'. If you missed out on the first two parts in
this series, simply enter here for Part 1 and here for
Part 2.
Vinny is very keen to get on with the trip forward in Time and hear about the
dinosaurs. He asks - 'Granny, when did the dinosaurs come to Earth? I know they
lived in the Jurassic time.'
'Well they are in the Mesozoic Era that we will talk about next' said Granny.
'This era is divided into three parts the Triassic, the Jurassic and the
Cretaceous periods.
The Triassic, which starts 225 MYA and ends 193 MYA saw abundant life in the
sea, on land and in the air. Reptiles, including the ancestors of dinosaurs and
mammals walked the Earth. The weather was warm and the sea reptiles like
ichthyosaurs, which had snouts and bodies shaped like dolphins, as well as
plesiosaurs who looked like big turtles with long necks and flippers were found
in the oceans. They used to feed on squid-like creatures which were abundant.
Strange creatures called coelophysis roamed amongst the cycads and palm trees on
the land.'
'We'll never remember the names of all those creatures' complained Terry 'I'm
going to draw some pictures of the ones that lived in the  sea'. 'That's an
excellent idea' said Granny 'maybe you can do a map of the world as it was at
the time and show where some of the pre-historic animals are believed to have
lived'. Enter the picture to the right to see the
whole picture Vinny drew.
'In the second period, the Jurassic which extends from 193 MYA to 136 MYA ,
South America and Africa were drifting apart and the Atlantic Ocean was being
formed. One way we know about the continents drifting is because fossil evidence
of the same, or similar life forms have been found on the different lands. We
also see the descendants of those pre-historic creatures today.
The rhea and our very own ostrich, as well as the emu from New Zealand all look
as if they had the same ancestor. They look different now because of the climate
and the environment they have lived in.' Granny continued...
'The weather was very warm and this encouraged flowering plants to develop.
There were many different types of dinosaurs, crocodiles, lizards, turtles,
pre-historic birds as well as flies with their wonderful complex eyes.'
Granny realised how difficult the subject was becoming and said. 'We can only
do a very small amount on each section here, but you can read it all up in more
detail in books from the library if you find it interesting.' (Granny invites
anyone to write to her for some suggestions at granny@scienceinafrica.co.za)
Lee was anxious to get out of the Jurassic and into the very last time period
in the Mesozoic Era..so he was pleased when Granny went on.
'The third and final period in the Mesozic era lasted from 136 MYA to 65 MYA
and is called the Cretaceous . The land masses began to move towards their
present positions. The weather was mild and a lot of the land was flooded. There
were many dinosaurs ranging from small ones like Lesothosaurus, who stood less
than 1m. high and lived in Africa, to huge ones like Tyrannosaurs, who was about
15 m high and lived in North America.. There were gulls and wading birds
too..'... 'Are they the ostrich's ancestors' asked Margie 'yes and if you look
at many of our birds today, you will see that they have a similar shape to some
of the dinosaur types of creatures that roamed the Earth all those many millions
of years ago.'
Granny went on 'Five reptile groups became extinct at the end of the
Cretaceous period ending off the Mesozoic rather sadly. The dinosaurs, the
pterosaurs, ichthyosaurs all....' - she stopped to look at Margie who had been
listening closely 'Does that mean they died Granny?' 'Yes it does - some people
say that an asteroid - which is like a star or a small planet -went off its
course and crashed to Earth, making so much dust that the sun couldn't get
through, causing the plants, the animals, birds and a lot of the sea life to
die.'
Granny heard sniffing and asked Margie what was wrong. . 'I'm sad' wailed
Margie.'becuase I don't believe the story - the dinosaurs aren't dead. I saw
them in the movie!'
Granny and the others couldn't help laughing.
'Don't laugh at her' said Grandpa from his chair across the room 'I'll take you
to the museum tomorrow and you can see how people have built up the fossil bones
of dinosaurs and made them look just like they did when they lived on the Earth.
Those ones you saw in the movie Margie were made by clever artists who designed
them on computers and passed their ideas on to the sculptors who brought them to
life for the camera '.
'Will we see tricetops?' asked Vinny 'he's my favourite.' 'Yes, and tyrannosaurs
Rex and lots of other 'sauropods' I'm sure.' said Grandpa.
The Museum.
Margie was facsinated with the entrance to the museum. She flung her arms
around a big marble column. It felt smooth and cool. 'Mind you dont knock it
down like Samson' joked Lee. The attendant at the door gave them a warning
glance and made a mental note to keep an eye on this 'unruly' bunch as they
scattered in different directions into a spacious room filled with unbelievable
things.
Granny, Terry and Ann looked at a mammoth in a glass case, while Lee and Vinny
stared at the skeleton of a dinosaur. Margie looked at the glass cased lining
the walls containing hundreds of tiny fossils. Grandpa came and picked Margie up
'See the skeleton' he said.  Margie smiled and nodded' 'well the bones are copies
of the real ones that have been found. When we go on to the next room, we'll see
how all the pre-historic animals have been made from the bones of dinosaurs like
this one' Grandpa put Margie down and she looked up at him and asked 'Why has
the baby elephant got so much hair?' 'Come on Granny help me out here I'm not
into dead animals' said Grandpa. See some of the
creatures they saw at the museum by clicking on the picture above.
'He's a baby mammoth and his sort were the ancestors of our elephants '
explained Granny 'he was probably found encased in ice, just as he is, in a cold
part of the world ,where he had been since his death thousands of years ago when
the whole of the North of the Earth was covered with ice and snow and many of
the animals had a thick coat of fur to protect them from the icy cold weather.'
'How did he die Granny?' asked Ann. 'A number of things might have killed him -
he might have been attacked by an Ice Age lion or rhino, or he might have been
killed in a Mammoth hunt by the early men who were around then, or he might have
just died because his mother had been killed in a hunt and he couldn't find food
or keep warm without her.' explained Granny. 'but we won't 'meet' him until much
later in the first part of the Quartenary period.
'Come on girls' said Grandpa taking Ann and Margie's hands in his, 'that's
enough sad tales for the day - lets go and see some 'smiling' dinosaurs next
door.'
 The boys had gone on ahead 'Wow!' exclaimed Vinny as they approached the huge
glass display cabinet containing some pre-historic animals that roamed the Earth
in the Triassic, Jurassic and Cretaceous periods - 'Dinosaurs for Africa!'...
'Not just for Africa - but for America, Europe, Australia as well' gasped Lee.
'Now we're really back in the 'Mesozoic Era'. Click
on the picture to the right to see and amazing view of creatures from this
period.
The children spent ages taking in all the different animals, sea life and
flying creatures to be seen. 'I've found Triceratops!' shouted Vinny. Granny put
her finger to her lips as the eagle eyed attendant entered the hall. He decided
to put himself at the door to this display. Granny walked over to where the
children had grouped themselves in front of the creatures from the Cretaceous
era.. 'I know we're all excited to be here - but let's not get too noisy'.
As they were leaving the museum a few hours later, Grandpa said 'I'm tired of
being inside on such a beautiful day - lets go and take a look at some nice
LIVING animals'.
'Where?' asked Ann
'I know' said Terry 'at the Zoo.'
"That's a great idea' said Granny as they climbed into the car.'
Next month we join the group at the Zoo where they learn more about life
forms in the Cenozoic Era - which began 65 MYA. Here we'll meet some interesting
LIVE Animals.
This Month's Poem
Window on the Dinosaurs
Dinosaurs existed - this fact is very sound.
We know from the evidence of fossils found.
We can tell from their teeth what they chose to eat
If they lived on plants or hunted for meat
Fossil eggs too, tell a lot when found
As do fossilized footprints exposed in the ground
We're really not sure what colours they were
Or the texture of their skin, or if they had fur
We know some were plodders and others moved fast
And how they inhabited the Earth so vast
Look at the Triassic in 'window one'
You will see Coelophysis out for a run.
In 'window two' you might recognise
Brachiosaurus with his tiny head in the skies
Stegosaurus, the patterned 'roof reptile'
Lived in the Jurassic for a very long while.
Plesiosaurus is out of the water and on land -
To see why the 'fish lizard' Ichthyosaurs lies on the sand.
In the third and last 'window' the Earth was alive
With many strange creatures who did not survive.
Flying reptiles like Pteranodon are seen no more
And our old friend' Triceratops is gone for sure.
We can be very pleased - you will agree
That from Tyrannosaurus we don't have to flee.
Tsintosaurs lived on pine needles and twigs so it's said
A very strange creature with an extension on it's head.
Styracosauruses looked very fierce in the Cretaceous
With a halo of horns, plus one on their faces.
Dinosaurs with strong teeth ate plants in the sun
Iguanodon looked ferocious - but maybe he was fun.
The total demise of the dinosaur
Gave mammals a chance to come to the fore
New forms of plants joined those that survived
Some insects were lost and some new forms arrived.
More is known now of the threats facing life on Earth.
Let's all share concern for the home of our birth.
Jenny Marais Jan.2002.
Next month we join the group at the Zoo where they learn more about life
forms in the Cenozoic Era - which began 65 MYA. Here we'll meet some interesting
LIVE Animals. 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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