Fossil fungi and arthropod body parts are present in one of 27 unhatched eggs in a turtle egg clutch from the Lower Cretaceous (Albian) Liangtoutang Formation, Zhejiang Province, China. The fossil fungal structures include branching septate hyphae, conidiophores supporting multiple phialides, and chains of up to five basipetal conidia (asexual spores). The morphology of the fossil fungus is similar to extant taxa within the genus Penicillium (order Eurotiales), making it the first reported intact Early Cretaceous asexual ascomycete and the earliest record of a presumed intact Penicillium. Biomineralization, a physiologic response to calcium-rich microenvironments, occurs in some extant fungi and may have facilitated detailed preservation of the fossil specimen. This rare evidence of fungal-animal association provides clues to clutch-related paleoecological interactions. The fungus-bearing egg occurs on the clutch periphery, whereas adjacent and more distant eggs show no evidence of fungal invasion. We suggest that the fungi were opportunistic contaminants invading after the egg was compromised, and the fungus failed to spread to adjacent eggs prior to burial and fossilization.