👉 Ceratothoa is a genus of ancient plants that were common in the Amazon rainforest during the Palaeozoic era, around 54 million years ago (Ma). These plants were characterized by their large leaves and spines, which provided them with protection against herbivores. The genus was named after the Greek word "cerato," meaning "thin" or "short," as they were thought to have been adapted for a short lifespan in the forest environment.