  Many extensions of the Standard Model have to face the problem of new
unsuppressed baryon-number violating interactions. In supersymmetry, the
simplest way to solve this problem is to assume R-parity conservation. As a
result, the lightest supersymmetric particle becomes stable and a
well-motivated dark matter candidate. In this paper, we show that solving the
problem of baryon number violation in non supersymmetric grand unified theories
(GUT's) in warped higher-dimensional spacetime can lead to a stable
Kaluza-Klein particle. This exotic particle has gauge quantum numbers of a
right-handed neutrino, but carries fractional baryon-number and is related to
the top quark within the higher-dimensional GUT. A combination of baryon-number
and SU(3) color ensures its stability. Its relic density can easily be of the
right value for masses in the 10 GeV--few TeV range. An exciting aspect of
these models is that the entire parameter space will be tested at near future
dark matter direct detection experiments. Other exotic GUT partners of the top
quark are also light and can be produced at high energy colliders with
distinctive signatures.
