ECOLOGICAL ANALYSIS OF A MIXED WETLAND-TO-XEROMORPHIC PLANT ASSEMBLAGE AND ASSOCIATED ARTHROPOD DAMAGE IN THE BASHKIRIAN OF NEW ENGLAND, USA

In this work, we investigate patterns in the flora of the Wamsutta formation, which is a rare non-marine-influenced upland site from the Pennsylvanian (Bashkirian) of Massachusetts, along with its associated arthropod damage.

We identified 83 distinct foliage morphotypes in the Wamsutta flora based on unique morphologies observed in specimens or groups of specimens, and a total of 131 morphotaxa (which includes stems, roots, seeds, and reproductive structures). To ensure comprehensive analyses and prevent errors from morphotyping subjectivity, we performed all investigations at both the morphotype and morpho-clade levels.

The flora at the site displays a co-dominance of xeromorphic and mesomorphic-to-hygromorphic elements. Among the xeromorphs are abundant cordaitaleans, as well as noeggerathialeans and, perhaps, other progymnosperms, while the mesomorphic-to-hygromorphic elements consist of sphenopsids, marattialean tree ferns, lycopsids, and medullosan pteridosperms. The case of equitable dominance of the two classes becomes evident as plant remains from both classes could be found on the same slab, and the average state of the macrofossil preservation is similar between the two classes (although there is variation within each class). We, therefore, suggest that these plants occupied the same landscape, and their differentiation was likely due to variations in niches.

We also identified plant-arthropod damage in this flora. While the frequency of damage was rare, we found numerous damage types (DTs) from three distinct functional feeding groups (FFGs) (piercing and sucking, galling, and oviposition). A literature survey shows that these results align with what is known from a coeval Bashkirian site in Ukraine, the only other flora from this time that had reported arthropod damage. Overall, this site provides a unique window into the ecology of the early Pennsylvanian uplands.