Understanding the bestiary of the frescoes in the Basilica of St Francis of Assisi, Italy as an <i>ante litteram</i> zoological atlas

From the period of early cave art onwards human beings have always drawn and painted animals. At the end of the Middle Ages, the development of painting techniques allowed animal depictions to be so detailed that not only were morphological and ethological features recognizable, but also an actual taxonomic classification up to the rank of genus or even species became possible. On the assumption that iconographic representations were designed for an immediate and easy identification, an analysis of the animal representations in the frescoes of the Basilica of St Francis of Assisi (Italy) was performed to evaluate the animal species present there. It is considered that these wall paintings create a de facto bestiary. Consequently, this list of species was compared with the Lista rossa IUCN dei vertebrati italiani 2022 [ 2022 IUCN Red List of Italian vertebrates]. This ante litteram zoological atlas underlines that a great number of species common in the 13th–14th centuries, are nowadays considered endangered and in need of protection. This paper shows how a multidisciplinary approach in the fusion of artistic and scientific disciplines can be considered both as a window to the past whilst also supporting the study of zoological biodiversity.