Walking trails of the giant terrestrial arthropodArthropleurafrom the Upper Carboniferous of Kentucky

Arthropleurids were terrestrial, millipede-like arthropods. The genus Arthropleura Jordan from the Upper Carboniferous reached an enormous size of 2 m or more in length (Hahn et al., 1986). Occurrences are rare and the chronologic and paleogeographic distribution of Arthropleura coincides with the tropical Euramerican floral belt of the Carboniferous (Rolfe, 1969). The Carboniferous was a time of high atmospheric O2 levels (35%) compared to the current 21%, which may have favored the development of large terrestrial arthropods of this time (Dudley, 1998; Graham et al., 1997; Berner, 2001). Body fossils of Arthropleura range from the Visean to Early Permian (Rolfe, 1969; Schneider and Barthel, 1997), while trackways have been reported from the Visean (Pearson, 1992) to Stephanian (Langiaux and Sotty, 1977; Castro, 1997; Fig. 1). Arthropleura fragments have been described from Ohio, Pennsylvania, Illinois, and Nova Scotia. Only four Arthropleura trackway sites have been described from North America (New Mexico, Kansas, Nova Scotia, and New Brunswick ). Trackways provide information about size and locomotion that is not discernable from fragmentary body fossils. Figure 1 —Stratigraphic distribution and age for Arthropleura body and trace fossils. Numbered references in table: 1—Pearson (1992); 2—Briggs et al. (1979); 3—Ferguson (1966, 1975); 4—Briggs et al. (1984); 5—Briggs et al. (1984), Ryan (1986), McDonald and Gibling (2001); 6—Hunt et al. (2004); 7— Mangano et al. (2002) 8-Langiaux and Sotty (1977); 9—Castro (1997); 10—Rolfe and Ingham (1967); 11—Waterlot (1934, 1935), Guthoerl (1935, 1936); Rolfe (1969), Becker and Engel (1984); 12—Richardson (1959); 13—Hannibal (1997), Easterday (2001); 14—Proctor, 1998; 15—Schneider and Barthel (1997) The specimens of this study are well-preserved …