FIRST RECORD OF THE INVERTEBRATE ICHNOFOSSIL HAMIPES FROM THE LOWER PERMIAN OF NEW MEXICO

New Mexico’s Early Permian vertebrate track record has received considerable attention over the last decade and is now recognized as a global standard. However, its Early Permian invertebrate ichnofaunas are less well known and have been relatively understudied. Here, we document an occurrence of Hamipes , an invertebrate ichnotaxon that has previously been unreported from New Mexico. The specimen (NMMNH P-32661) is from New Mexico Museum of Natural History locality 1339, which is in the upper part of the Sangre de Cristo Formation (Wolfcampian) of San Miguel County, New Mexico. A diverse vertebrate ichnofauna is present, dominated by typical Early Permian ichnogenera such as Dromopus and Batrachichnus . An invertebrate ichnofauna is also present, consisting of ichnogenera such as Paleohelcura and Dendroidichnites . The paleoenvironment is interpreted as a sheet-flood deposit on an extensive floodplain. transect of the state. The southernmost ichnoassemblage, centered near Las Cruces, is found in coastal tidal flat facies of the Robledo Mountains Formation that show periodic freshwater influence. This diverse ichnoassemblage is distinct in having four arthropod ichnotaxa, including Tonganoxichnus robledoensis , which are known only from their type localities within the Robledo Mountains Formation. Another ichnoassemblage, from the central part of the state around the Lucero uplift and Socorro, is low in ichnodiversity. It is found in transitional brackish waterinfluenced facies low in the Abo Formation. The characteristic ichnotaxon within this ichnoassemblage is Palaeophycus , an infaunal burrow attributed to polychaete makers. Another ichnoassemblage occurs in the northern part of the state, near Villanueva in San Miguel County. It is found within floodplain facies of the Sangre de Cristo Formation that were far inland during Wolfcampian time. The ichnodiversity of this arthropod-dominated ichnoassemblage is less than that of the southern ichnoassemblage. However, it may contain different ichnotaxa in addition to Hamipes . Continued investigation is needed to further determine the compositional similarities and differences between these ichnoassemblages.