The study of primordial non-Gaussianity can explore the particle content of our Universe at the highest energies, inaccessible to particle accelerators. Even when inflation is driven by a single degree of freedom, the excitation of additional particles present during inflation leaves an imprint on correlation functions of primordial curvature perturbations. In particular, the presence of particles with masses of the order of the Hubble parameter during inflation, generates distinct bispectrum and trispectrum of primordial curvature perturbations, shape of which are determined by the mass and spin of the particles. This in turn impacts the clustering statistics of the large-scale structure at late times, which can therefore be used to constrain the characteristics of such particles. In this talk, I will discuss some of our recent works on investigating the potential of upcoming galaxy surveys, such as EUCLID and DESI, in detecting massive and partially massless new inflationary-era particles.