part_of part of part of has developmental contribution from has developmental contribution from has potential to develop into has potential to develop into meninx presumptive structure mesenchyme derived from head neural crest future meninx primary meninx A developing mesenchymal capsule that covers the developing brain and spinal cord and is the precursor of the meningeal cluster. In mammals this gives rise to the arachnoid mater, pia mater and dura mater. In cyclostomes and fishes, the future meninx gives rise to a single meningeal layer, the primitive meninx. primordial meninx meninx primitiva primitive meninx meningeal cluster