Comment on “The vertebrates of the Anisian/Ladinian boundary (Middle Triassic) from Bissendorf (NW Germany) and their contribution to the anatomy, palaeoecology, and palaeobiogeography of the Germanic Basin reptiles” by C. Diedrich [Palaeogeography, Palaeoclimatology, Palaeoecology 273 (2009) 1–16]

The Middle Triassic vertebrates are proving to be very important witnesses of the post P/Tr crisis recovery, but also of the palaeobiology and paleogeography. The western Tethys (especially the Monte San Giorgio fossiliferous series) and the Germanic Basin are of particular interest as they show similar vertebrate assemblages in somewhat different environmental patterns and ages. Furthermore, the MSG specimens are usually complete and concentrated in different levels spanning from Late Anisian to Late Ladinian, while vertebrates of the Germanic basin often consist of scattered remains, sometimes gathered in bone-beds. In the last years Diedrich proposed a number of restorations, concerning both organisms and palaeoenvironment. Very often his work does not consider other Authors’ papers, and a few concepts, such as the supposed ‘anatomic convergence’ between a sauropterigyan reptile and a mammal, appear scientifically unsound. In this comment the author points out some uncertain data and unproven conclusions in Diedrich’s paper