Early Permian Ichnofossils from the northern Caballo Mountains, Sierra County, New Mexico

An extensive ichnofossil assemblage is reported from ripple-laminated sandstones ~ 20 m and ~45m above the base of the Abo Formation, near Lone Mountain in the northern Caballo Mountains (Sierra County,New Mexico). This assemblage is of early Wolfcampian age and derived from sheetflood sandstones depositedon a broad floodplain with no direct marine influence on sedimentation. Invertebrate ichnofossils are assignedto Permichnium sp., Stiaria intermedia and cf. Tonganoxichnus robledoensis, and several problematic inverte-brate ichnofossils are unassigned. The tetrapod ichnofossils are assigned to Batrachichnus salamandroides, Dromopus lacertoides, cf. Gilmoreichnus hermitanus and Dimetropus nicolasi. Tonganoxichnus, Batrachichnus and Dromopus are the most common ichnofossils, and the relatively low ichnodiversity distinguishes the Caballoichnoassemblage from that of the Robledo Mountains Formation in the Robledo Mountains. The differencesbetween the Caballo and Robledo Mountains ichnoassemblages are not age related, but most likely reflectpaleoenvironmental differences along a north-south transect from tidal flat (Robledo Mountains) to inland flood-plain (Caballo).