Charmonium tetraquarks and pentaquarks or an additional quark?

Most of the exotic hadrons discovered over the last 20 years fit into the quark model as normal mesons and baryons if the existence of a seventh flavor of quark is hypothesized. If the quark has a mass of $\sim$2.9 GeV, a charge of $-\tfrac{1}{3}$, and light-scalar-mediated decays to other quarks and $c\bar{c}$, then it is able to reproduce the mass, spin, parity, production and decay modes of most observed exotic hadrons. Predictions are made for additional hadrons as well as new production and decay modes for observed exotic hadrons.