Contrary to some rumors and some skepticism, the archaeology and radiocarbon chronology appear to support only Neanderthals as the material authors of the first "mode 4" stone industry of Western Europe: the Châtelperronian.
They still allow for it, and especially the novel behavior of production and use of durable ornaments (on bone mostly), to have been influenced by the penetration of Homo sapiens.
Jean-Jacques Hublin et al., Radiocarbon dates from the Grotte du Renne and Saint-Césaire support a Neandertal origin for the Châtelperronian. PNAS 2012. Open access → LINK 
The transition from the Middle Paleolithic (MP) to Upper Paleolithic (UP) is marked by the replacement of late Neandertals by modern humans in Europe between 50,000 and 40,000 y ago. Châtelperronian (CP) artifact assemblages found in central France and northern Spain date to this time period. So far, it is the only such assemblage type that has yielded Neandertal remains directly associated with UP style artifacts. CP assemblages also include body ornaments, otherwise virtually unknown in the Neandertal world. However, it has been argued that instead of the CP being manufactured by Neandertals, site formation processes and layer admixture resulted in the chance association of Neanderthal remains, CP assemblages, and body ornaments. Here, we report a series of accelerator mass spectrometry radiocarbon dates on ultrafiltered bone collagen extracted from 40 well-preserved bone fragments from the late Mousterian, CP, and Protoaurignacian layers at the Grotte du Renne site (at Arcy-sur-Cure, France). Our radiocarbon results are inconsistent with the admixture hypothesis. Further, we report a direct date on the Neandertal CP skeleton from Saint-Césaire (France). This date corroborates the assignment of CP assemblages to the latest Neandertals of western Europe. Importantly, our results establish that the production of body ornaments in the CP postdates the arrival of modern humans in neighboring regions of Europe. This new behavior could therefore have been the result of cultural diffusion from modern to Neandertal groups.
Importantly, it is also confirmed that Grotte-du-Renne (Arcy-sur-Cure, Burgundy) is one of the last Chatelperronian, and therefore surely Neanderthal, pockets in Western Europe, co-existing with Aurignacian North-East and South-West of it, what is suggestive of this latter culture, probably the first settlement by Homo sapiens, expanding to SW Europe via Italy rather than Germany.
Finally, according to our results, the CP Neandertals of the Grotte du Renne, Saint-Césaire, and Les Cottés clearly postdate the earliest likely modern humans remains documented in western Europe (43) and largely overlap in time with the early Aurignacian in the Swabian area (44) and in southwestern France (42).
|Fig. S1. Geographical distribution of the Châtelperronian assemblages and location of the three main Châtelperronian sites discussed in the text.|
Hat tip to Linear Population Model.