What are preons and why are they no longer part of physics?

[dimension10]

Can anyone please tell me what are preons. I searched wikipedia, google scholar and many other sites but all I got is that they occupy 0 space and that that they are older than the standard model itself!

 

[tom.stoer]

Afaik there is no common accepted preon model that is able to reproduce the known particles, account for their masses, quantum numbers and interactions. Preon models were considered due to the fact that there are now many fundamental particles (6 quarks, 6 leptons, the W, Z, photon and gluon gauge bosons, perhaps 1 Higgs) and that one would like to reduce this large number to a smaller set of fundamental objects.