1996/04/01 by Leonard R. Brand, Jon Kramer · 1 citation
Earth and Planetary Sciences · #Paleontology and Evolutionary Biology #Evolution and Paleontology Studies #Geological formations and processes #Geology #Paleontology #Permian #Vertebrate #Front (military) #Trace fossil #Invertebrate #Structural basin #Oceanography #Ecology #Biology
paper · doi:10.1080/10420949609380129
openalex publication_date 1996/04/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
The only fossils in the Permian Coconino Sandstone of northern Arizona are abundant fossil trackways. A slab of Coconino Sandstone contains underprints of both vertebrate and invertebrate animals, exposed at two levels separated by a 1–2 mm layer of sand. The underprints on the lower level are deeper and much more distinct than the same trackway exposed on the higher level. The tracks on the upper level were partly infilled by the fine sand, which does not contain clays or other material that could provide cohesive‐ness. The trackways on this upper level also appear to be underprints, but formed closer to the surface. Many other fossil trackways in the Coconino Sandstone are probably also underprints, since they closely resemble the documented underprints. The mechanics of underprint formation may also explain the origin of some tracks that are very deep, with steep sides that even overhang the front of the track.