ARCHAEOCALAMITES LAZARII,SP. NOV.: THE RANGE OF ARCHAEOCALAMITACEAE EXTENDED FROM THE LOWERMOST PENNSYLVANIAN TO THE MID-LOWER PERMIAN

Archaeocalamites lazarii, sp. nov., is based on a few vegetative compressions from the mid-Lower Permian Leonard Series near Fulda, north-central Texas. It is a minor component of a rich biota that includes sphenophylls, pteridophylls, conifers, conchostracan crustaceans, eurypterids, arachnids, insects, xenocanth sharks, and coprolites attributed to tetrapods. Biota and sedimentology indicate deposition in a small freshwater body on a deltaic floodplain. Leaves of A. lazarii differ in size and posture from those of the widespread and characteristically Mississippian aggregate species A. radiatus; nonpreservation of rooting and reproductive organs prevents interpretation of its phylogenetic relationship with other equisetaleans. The main significance of A. lazarii is that it extends the recorded stratigraphic range of the Archaeocalamitaceae from the lowermost Pennsylvanian (Namurian B) to the mid-Lower Permian (Artinskian), leaving a hiatus in records of approximately 55 Ma. This Lazarus taxon also occurs with possibly the youngest recorded eurypterid.