Generations of ancient, reclusive bees established their abodes within the tooth sockets of a fossilized mandible, a discovery recently made in a cavern on the Caribbean island of Hispaniola.
This represents an unprecedented observation of ancient bee species colonizing pre-existing cavities within fossilized remains, underscoring the adaptable nature of shelter selection.
Paleontologists surmise that the jawbone originally belonged to a rodent akin to a capybara (Plagiodontia araeum), likely deposited in the cave by a predatory owl that consumed the now-extinct mammal and subsequently discarded its jawbone.
Over elapsed time, the jawbone’s teeth became dislodged and dispersed as the specimen was gradually enveloped by fine clay silt.
Within the vacated spaces, known as dental alveoli, a newly identified species of burrowing bee, Osnidum almontei, fashioned a multi-generational dwelling.
This remarkable finding came to light because the conspicuously smooth interior surface of one of these alveoli captured the attention of paleontologist Lazaro Viñola Lopez during his excavation of fossilized bones at the Florida Museum of Natural History.
“Micro-computed tomography examinations of the host bones reveal evidence of multi-generational occupation of the same cavity, suggesting recurrent usage and a certain degree of commitment to specific nesting sites,” Viñola Lopez and his collaborators articulate in their published scientific paper.
“Nesting fidelity in bees is associated with the consistency or specificity with which a particular bee species or individual chooses and utilizes specific nesting locations or materials.”
Once the researchers recognized the pattern, they identified numerous similar instances of the bees’ nesting cells embedded within bones throughout the sediment, including one found within the mandible of a sloth.
While these may constitute solely trace fossils (ichnofossils) of O. almontei, they nevertheless impart a compelling narrative regarding the bees’ behavioral ecology.
“The nesting cells of Osnidum almontei exhibit a highly opportunistic characteristic, utilizing all available bony chambers within the sedimentary deposit,” the research team reports.
“Furthermore, the substantial density of nests across the deposit indicates that this cave served as a communal nesting aggregation area for this solitary bee species over an extended temporal span.”
