Probably few people think about what happens in the famous Altamira Cave beyond the question of the cave paintings. What happened there can be described as "modern" when we understand that life is measured on a different scale, although its occupation almost 40,000 years ago, and its decoration more than 13,000 years ago, may seem distant to us. The men and women who lived there coexisted with other forms of life that have gone unnoticed until very recently. The protagonists of our story are, in addition to these people and their paintings, some microorganisms called fungi, and a small animal with six legs but no wings (it cannot therefore be considered an insect) called springtails. The relationship between them may not be obvious, but there is a network of facts that connects them. We will talk about them in a moment.

Caves are interesting places. On the one hand they offer shelter to some animals, but on the other hand their conditions do not favor life: there is no light, and therefore no plants, its temperature is leave and uncomfortable for most organisms, and consequently there is no food to take advantage of. But some leaves or branches dragged by the water, or the excrements of some animal, can serve as an appetizer, and then the vital network begins, because that initial "organicsubject " is food for one of our first protagonists: the fungus. This activity, of degradation because something that has form ceases to have it, allows the growth of the fungus in the form of mycelium, thin white filaments, and finally the spores appear, which serve as seeds. The fungus becomes food for another organism, the springtail, which ingests both the mycelium and the spores, feeding on the former and depositing the unaltered spores together with its excrement at the end of the digestive process. In turn, the springtails will be preyed upon by other animals, such as spiders or pseudoscorpions in the caves, which would be the equivalent of the great predator of the savannah feeding on the gazelles (these would be the springtails in the caves). The cave therefore, like any other habitat, has its own community of inhabitants, present in them for more than those 40,000 years of our prehistoric painters.

A few days ago it was published in Zookeys[1] that a new species of springtail lived in Altamira. It has become clear that "nothing new", but until now no one had given it a name. It has been a long time since the activity of speleology, which in its beginnings allowed the discovery of the Altamira paintings, turned its eyes towards the living part of the caves. Since then, hundreds of species have been "discovered" (more than 200 in the caves of the Iberian Peninsula alone), and entomologists and zoologists are the scientists in charge of doing so. On this occasion, specimens captured in the year 2000 have been subjected to a rigorous examination, based on being compared with all the species previously described, and all over the world! What is looked at is their coloration (some have repeating patterns of spots), their issue eyes (springtails have a maximum of eight, but those that live in caves usually lose some or all of them), the length of their antennae (the longer they are, the greater their capacity to "smell", since in insects the antennae serve as the organ of smell), or the length of their nails (in caves they are longer, so that the animal can walk on water). This has taken many years, and until now we have not been sure that, indeed, the Altamira specimens deserved to have their own name: Pseudosinellaaltamirensis, which in Latin means "the Pseudosinella of Altamira".

One last question remains to be studied: whether the animals that inhabit the caves may have played a role in the degradation of some of the paintings. 13,000 years ago, to color their paintings, cave dwellers used pigments taken from minerals such as hematite, limonite or gypsum, and to make them moldable, they added charcoal and other organic substances such as grease or resin. And they applied them with animal hair or branches. Some of these materials can serve as food for fungi. If the conditions for their growth are right, and the springtails deposit spores on them, the paints could be damaged. To know the answer, a rigorous research must be carried out, and once again scientists will be taking the baton.

[1]Baquero E, Jordana R, Labrada L, Luque CG (2020) A new species of Pseudosinella Schäffer, 1897 (Collembola, Entomobryidae) from Altamira Caves (Cantabria, Spain). ZooKeys 989: 39-54 . https://doi.org/10.3897/zookeys.989.52361.