Berlese's Primitive Oribatid Mites Author van der Hammen, L. text Zoologische Verhandelingen 1959 40 1 93 http://www.repository.naturalis.nl/document/148866 journal article ORI111 0DC6B575-3CB3-41C1-A3EC-850520AE4487 PTEROCHTHONIIDAE Grandjean, 1950 Among the Enarthronota Pterochthonius angelus is remarkable by its exceptional habitus, whilst many of its characters must be regarded as unique and primitive. It is impossible to classify the species in one of the above-mentioned families, so that Grandjean (1950) created a separate family Pterochthoniidae .