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2015/02/13

MONTESSORI THE GREAT LESSONS : The Devonian Period



 The Coming of Life



 The Devonian Period

  The name comes from a part 
of England called Devon where the
 first fossils of this period was found.



This period includes the Age of the Fish.
Since they had no enemies they developed and
increased tremendously. This is not the fish we
know today - they had no skeletons but a type
of external armor or shell. In this period the 
oceans receded and seas were formed between
the different land masses. Animals and plants
remained in the muddy bottoms and had to
learn how to live in their new surroundings.


The algae grew longer and covered themselves
with little leaves. Then the swamp lands began
to dry up and the plants had to put down roots
in order to keep themselves upright
and to go in search of water.


  The armored fish began to disappear and
vertebrate fish began to appear. These fish
developed vertebral column and began to race
swiftly through the seas. Some fish learned
to live out of water for short periods of time, 
transforming their swim bladders into lungs.


 These lung-fish were called Dipnoides
  (dual respiration) and exist today. 
Fish with ribbed fins  appeared;
also the first land scorpions;  while
marine scorpions disappeared.


    Dinosaur graphics
  Pinegreenwoods Montessori