  The low energy physics of fractional quantum Hall (FQH) states -- a paradigm
of strongly correlated topological phases of matter -- to a large extent is
captured by weakly interacting quasiparticles known as composite fermions
(CFs). In this paper, based on numerical simulations and effective field
theory, we argue that some \emph{high energy} states in the FQH spectra
necessitate a different description based on \emph{parton} quasiparticles. We
show that Jain states at filling factor $\nu{=}n/(2pn\pm1)$ with integers
$n,p{\geq}2$, support two kinds of collective modes: in addition to the
well-known Girvin-MacDonald-Platzman (GMP) mode, they host a high energy
collective mode, which is interpreted as the GMP mode of partons. We elucidate
observable signatures of the parton mode in the dynamics following a geometric
quench. We construct a microscopic wave function for the parton mode, and
demonstrate agreement between its variational energy and exact diagonalization.
Using the parton construction, we derive a field theory of the Jain states and
show that the previously proposed effective theories follow from our approach.
Our results point to partons being "real" quasiparticles which, in a way
reminiscent of quarks, only become observable at sufficiently high energies.
