When seldom life history events serendipitously get documented by exceptional preservation in the fossil record, a unique telescopic opportunity arises for interpreting fossils within their paleoenvironment as well as for understanding ancestral relationships of current life forms. We present a rare glimpse of live birth by a terrestrial mother snail, incidentally, engulfed by amber as she released her young in a tropical forest during the mid-Cretaceous (early Cenomanian). The exceptional finding featuring the preservation of a snail’s 99-million-year-old soft-body together with five neonate shells represents the earliest known fossilized incidence of viviparity in a terrestrial snail. Based on high-resolution photographs and µCT scans, we describe the mother snail as a new species of cyclophoroid, Cretatortulosa gignens sp. nov. Our finding provides remarkable perspectives for interpreting gastropod evolution 80 million years earlier than the fossil record has known up to now. It shows that viviparity was already a relevant reproductive strategy in the Cretaceous, probably increasing the offspring’s survival chance in a predator-lurking tropical forest.