AMPHIBIAN FOOTPRINTS FROM THE MIDCARBONIFEROUS OF NORTHUMBERLAND, ENGLAND - SEDIMENTOLOGICAL CONTEXT, PRESERVATION AND SIGNIFICANCE

A trackway and footprints produced by a large amphibian have been disc overed in Namurian strata on the coast of Northumberland, near Howick, in northeastern England. They occur on a thin layer of mud upon the s urface of a sandstone bed deposited by a small delta on a coastal plai n. They were preserved by subsequent deposition of a thin sandstone fr om the flooding of a nearby channel. Abandonment of the area led to th e growth of plants and the formation of a thin coal seam, so that the footprint sandstone was rootleted to form a seatearth. The Howick foot prints average 18 cm in length and 14 cm in width. The trackway is poo rly preserved and appears to consist of at least five footprints arran ged either side of a groove 0.19 m in width which is interpreted as a body drag trace. The external trackway width is 0.7 m, and the stride is 1.4 m. At Howdiemont Bay 3 km south of Howick Bay, more footprints occur of about the same size, but also poorly preserved, upon the surf ace of a fluvial sandstone. These footprints are some of the earliest occurring in Carboniferous strata in Europe. Although preservation of both sets of footprints is now poor, the Howick footprints can be comp ared to the ichnogenus Baropezia.