Hundreds of mummified bees inside their cocoons —from almost three thousand years ago— have been found on the southwest coast of Portugal, in a new paleontological site in Odemira.
The discovery of mummified bees, in which the professor from the Department of Crystallography, Mineralogy and Agricultural Chemistry of the University of Seville, Fernando Munizhas been published in the international magazine Papers in Paleontology.
The study details the appearance of bees “prepared to leave their nests or cells in an exceptional state of preservation”, or mummified, found inside their cocoons. In these, pollen supplies of the type Brassicaceae, that is to say, coming from common herbaceous species, but that demonstrate their particular taste for a single monofloral variety.
The good state of fossilization in which bees have been found is, according to the authors of the publication, “extremely rare”, since normally the skeleton of these insects decomposes quickly. Thus, thanks to the magnificent degree of conservation, the team of researchers has been able to determine the type of bee, its sex and even the contribution of pollen left by the mother when she created the cocoon.
The lack of oxygen and change in temperatures contributed to the existence of mummified bees
Bees are one of the most important groups of pollinating insects and include more than 20,000 species. Approximately three-quarters of all wild bee species nest on the ground and spend much of their life cycle underground, making it easy to preservation of their nesting structures.
In the published article, the researchers describe dense aggregations of thousands of fossil nests found per square meter in southwestern Portugal. These nests or cells have been assigned, mostly to the ichnogenus Palmiraichnus.
The record of this ichnogenus represents a unique opportunity to study in detail the well-preserved architecture of the nests and the possible environmental causes of death and burial that led to the preservation of the specimens 3,000 years ago.
According to the study, although the cause of death of these mummified bees found remains a mystery, oxygen depletion due to a flash flood and the consequent drop in temperatures at night could be plausible causes. The southwest coast of Portugal lived in the Neoglacial interval slightly colder periods and higher precipitation in winter, favorable climatic conditions for the study of these fossils.
“Bees are essential pollinating insects for ecosystems, in such a way that their decline would directly affect biodiversity, that is, the many species of plants and animals that directly or indirectly depend on them, including us human beings. For example, it is known that bees pollinate 70% of the crops people eat and 30% of the livestock feed. Human activities, such as intensive agriculture, the use of pesticides and insecticides and climate change are currently causing one in ten species of bees to be in danger of disappearing in Europe”, Muñiz emphasizes.
“Knowing and interpreting the ecological reasons both for the presence of this population of bees, and for their death and mummification 3,000 years ago, could help to understand and establish resilience strategies in the face of climate change. Like, for example, comparing the ecological imbalances motivated by natural parameters with the current imbalances and the way in which they are affecting the current species of bees”, explains the main author, Carlos Neto de Carvalho.
This article was first published on SYNC