Anderson noted that P. capensis was larger than the rest of the Petalichnus ichnospecies, as well as the presence of an unusual median drag line for the ichnogenus (although this was not present in all the specimens).

These tracks were located at a low angle with respect to the sometimes present median line, which is believed to be due to the telson ("tail") touching the substrate.

The bilobed marks is thought to be "eight"-shaped due to the long spines of the sixth appendage of an onychopterellid eurypterid, presumably Onychopterella augusti, using a swimming stroke-like motion.

[5] Braddy erected in 1995 P. macdonaldi for Lower Permian trackways found in the Hueco Formation of New Mexico, becoming the youngest species of the ichnogenus.

Due to these characteristics it has been suggested that the producer was Adelophthalmus luceroensis, which has been found in nearby deposits (Madera Formation, central New Mexico).

[6] In 1843, the English geologist and paleontologist William Buckland described the now called BGS GSM 26037 (housed at the British Geological Survey in Nottingham, England) specimen as the result of the repeated impressions of three bony processes of the pectoral fin of an ambulatory (related or adapted to walk) fish, Icthyopatolites.

However, in 1996, Braddy and Lyall I. Anderson recognized the track as clearly that of a moderately large (around 20 cm, 7.9 in long) hexapodous arthropod similar to the eurypterid traits that were described before in other papers, and named it Palmichnium pottsae.

It lacked a median line, but it has been suggested that this is due to the buoyancy of the water surrounding the abdomen of the animal or the active held up of the telson on the substrate without touching it, allowing better locomotion.