Complete and articulated adult and juvenile Psittacosaurus sp. fossils have been found at Shestakovo (Chebula region) in Western Siberia. Although fossils of Psittacosaurus sibiricus have been found at Shestakovo locality before, this is the first time a bone-bed with whole skeletons has been uncovered.
Lopatin et al. (2015) have written a short paper on this new find, and included a rough diagram of how the fossils were preserved (find the paper here (paywalled)).
There's no indication that these Psittacosaurus have been preserved with any proto-feathers, such as those found on some specimens of P. mongoliensis. But the fossils are still being prepared, and as they were preserved in muds and silts, one can hope they will!
Lopatin, A.V., Mashchenko, E.N., Tarasenko, K.K., Podlesnov, A.V., Demidenko, N.V., Kuzmina, E.A. 2015. A unique burial site of Early Cretaceous vertebrates in Western Siberia (the Shestakovo 3 locality, Kemerovo Province, Russia). Doklady Biological Sciences, 462 (1): 148-151. dx.doi.org/10.1134/S0012496615030102.
Osborn, H.F. 1923. Two Lower Cretaceous dinosaurs of Mongolia. American Museum Novitates 95: 1-10.