Anomalous occurrence of the Gondwanan winged seed Fraxinopsis in a new Late Triassic (Norian) flora from west Texas, USA

The small Late Triassic flora described here from a new locality in Palo Duro Canyon, west Texas, USA is noteworthy because it includes specimens of a new species of the Gondwanan winged seed Fraxinopsis, F. patharrisiae sp. nov. This is only the second time that Fraxinopsis has been found in Laurasia and thus adds support to the theory that at least limited floral migrations did take place between Gondwana and Laurasia during the Late Triassic. In addition to Fraxinopsis the locality has yielded a new species of the platyspermic seed Samaropsis, S. texensis sp. nov., the remains of the cycadophyte leaf Zamites powellii, and the leafy shoots and pollen and seed cones of Palodurophyton quanahensis gen. et sp. nov., a conifer of unknown relationships that has cheirolepidian-like epidermal features. This flora occurs in the Tecovas Formation in the lower part of the Dockum Group of Late Triassic (Norian) age. The description of the flora contributes to our understanding of the Dockum flora and its distribution in the American southwest and adds to our knowledge of the Late Triassic flora of western Laurentia as well.

Research highlights
► A small previously unknown flora occurs in the Upper Triassic Dockum Group in Texas.
► The flora includes Zamites powellii and new species of Fraxinopsis and Samaropsis.
► A conifer Palodurophyton quanahensis gen et sp. nov. also occurs in the flora.
► Fraxinopsis is further evidence of plant migration between Gondwana and Laurentia.
► This study increases knowledge of the Upper Triassic flora of western Laurentia.