Horsetails are one of the most ancient plant groups still alive today. These segmented, reed-like plants first emerged over 300 million years ago and once formed tree-sized giants that dominated Carboniferous forests long before the rise of dinosaurs. The lone surviving genus, Equisetum, is now confined to wet forests and swamps, and has remained remarkably unchanged since at least the Early Jurassic.

Equisetites is a closely related genus of fossil horsetails that ranged from the Carboniferous through to the end of the Cretaceous. While some species closely resembled modern horsetails, others bore multiple cone-like reproductive structures (strobili) on lateral branches, rather than a single cone at the tip of fertile shoots. Many were also significantly larger, with a jointed, bamboo-like growth habit.

During the Mesozoic, Equisetites likely thrived in shallow, still-water environments, forming dense, water-reed-like thickets along the edges of lakes, wetlands, and floodplains.