The thin "tissue paper" protective layer over the brain is the
The answer is pia mater a lot referred to as basically the pia, is the subtle inmost layer of the meninges, the membranes adjacent to the brain and spinal cord. Pia mater is Medieval Latin meaning "tender mother". The two meningeal membranes are the arachnoid mater and the dura mater.
then that particular organisms become extinct.