Scientific databases must be able to efficiently run subset retrievals of multi-dimensional data sets. If the data sets are very large significant retrieval speedups can be obtained via parallelism. In this paper we present a new parallel distributed shared nothing R-tree architecture. To the best of our knowledge this is the first significant experimental study demonstrating practical application of parallel R-trees in a shared nothing environment. We argue that our new architecture is better than those proposed in the past and provide experimental results demonstrating actual speedups for several synthetic and real data sets. In addition, we conduct experimental studies to investigate the effect of several declustering strategies and communication parameters.