Diversity of small-leafed equisetaleans in Late Carboniferous coal swamps of Euramerica

A group of equisetalean shoots with distinctive small leaves occurs widely in the upper Bashkirian and lower Moscovian coal-bearing deposits of Euramerica. They have often been named Asterophyllites grandis and Asterophyllites charaeformis in the past, but the use of these names is illegitimate for these species. In this study, these shoots have been assigned to five fossil species: Asterophyllites delicatulus , Asterophyllites parvulus , Asterophyllites gracilis , Asterophyllites taylorianum , and Asterophyllites lubnensis . Two of the species are associated with Calamostachys strobili, while the other three are associated with Palaeostachya strobili. The distribution of the shoot species partly reflects differences in elevation and substrate conditions of where the parent plants grew.