The Great Thesaurus Rex

Come hither and hear my story of creature on the. sad path to its extinction.
This is more than a mere pity, caused it lived its life with great distinction.
This mighty creature was quite heavy, with an outer shell of leather.
But as it evolved, with the leather gone, it was light as a feather.
With the leather went the spine, but never faded in its brilliance....
More recently as their and they're merged into there, it lost much of its resilience.
It taught us sounds that sound the same, but meanings were contrary.
It taught us sounds that mean the same, from the shelves of our library.
But in a world of shortened language, where to and too are for.
We need this creature far more now, than we ever did before.
It made us all quite erudite, but never seem pedantic.
We could give you synonyms for words like truculent and sycophantic.
This was a friend, but like old friendships it may soon sadly fade away.
But like funerals and end of schools, oh how I loathe that day.
Mighty creatures walked this earth called Raptors and Triceratops.
And to give this creature, a name like those, well that clearly was a paradox
But the name might just have been some odd prognostication
For I fear that future generations will suffer because of its cessation.
So just like the mighty Stegosaurus is this creature next?
Of course you know that I speak of, the great Thesaurus Rex.