Comment on the Chu et al., paper 'Lilliput effect in freshwater ostracods during the Permian–Triassic extinction' [Palaeogeography, Palaeoclimatology, Palaeoecology 435 (2015): 38–52]

Chu et al. (2015, Lilliput effect in freshwater ostracods during the Permian–Triassic extinction) reported a sharp decrease of the size of freshwater ostracods through the terrestrial end-Permian extinction (EPE) interval of the Dalongkou Anticline section in Northwest China. The proposed work is however unacceptable because of taxonomic and methodological issues. Most of the identifications are rejected because of too poor preservation and generic misidentifications due to the unawareness of the abundant literature published for years on Permian freshwater ostracods. The proposed analysis of the size of the misidentified genus Darwinula considers the totality of the recovered specimens but is meaningless by ignoring the aspect of the ontogenetic development of ostracods. As a consequence, the observed reduction of size of ostracods could be related to changes in the taphonomic conditions or in the proportions of juveniles under special environmental, which have already been suggested for marine ostracods through the EPE.