中国科学院南京地质古生物研究所机构知识库

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 mCT 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 ear-lier than the fossil record has known up to now. It shows that viviparity was already a relevant reproduc-tive strategy in the Cretaceous, probably increasing the offspring's survival chance in a predator-lurking tropical forest. (c) 2021 The Authors. Published by Elsevier B.V. on behalf of International Association for Gondwana Research. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).