Revision of the ? Permian-Triassic Tetrapod Ichnogenus Procolophonichnium Nopcsa 1923 with Description of the New Ichnospecies P. lockleyi

摘要

Procolophonichnium is a globally distributed but rare tetrapod ichnogenus ranging from the ?Late Permian/Early Triassic through the Late Triassic. A Permian age of the holotype from the Karoo of South Africa, as has been proclaimed by some workers, is doubtful. Descriptions lack coordinates of the type locality but suggest instead a position in Lower Triassic strata. Procolophonichnium material from North and South Africa, central Europe, North and South America is re-evaluated. Furthermore, the new ichnospecies Procolophonichnium lockleyi from the Upper Triassic of the Germanic Basin is introduced, based on material with well-preserved trackways that show distinct morphological features, such as an extended heel behind digit V. Five ichnospecies are considered as valid: P. nopcsai (type ichnospecies), P. haarmuehlensis, P. nectouxi (new comb.) and P. polonicum as Procolophonichnium tracks from ?Upper Permian, Lower and Middle Triassic strata, and P. lockleyi ichnosp. nov. from the Upper Triassic. Trackmakers of Procolophonichnium were most likely therapsids based on the digit configuration and the phalangeal formula derived from preserved pads. A prococolophonid affinity, as was generally proclaimed, or the attribution to other groups such as captorhinids, is less probable.