Metatherian origin in the Early Cretaceous
Issue: Vol. 3 No. 3: September 2026
Type: Article
Published: 2026-09-24
Page range: 245-258
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Metatherian origin in the Early Cretaceous
- HAI-BING WANG+−
- YUAN-QING WANG+−
- PDF(6MB)
Institute of Vertebrate Paleontology and Paleoanthropology; Chinese Academy of Sciences; 100044 Beijing; China; Natural History Museum; London; SW7 5HD; United Kingdom; College of Earth and Planetary Sciences; University of Chinese Academy of Sciences; 100049 Beijing; China
Institute of Vertebrate Paleontology and Paleoanthropology; Chinese Academy of Sciences; 100044 Beijing; China; College of Earth and Planetary Sciences; University of Chinese Academy of Sciences; 100049 Beijing; China
mammals metatherians Jehol Biota Early Cretaceous evolution divergence
Abstract
The origin and early divergence of therians remain central questions in mammalian evolutionary history. The timing and mode of divergence between metatherians (the lineage including marsupials and their stem relatives) and eutherians remain poorly understood. The Early Cretaceous fossil record of metatherians remains sparse and is represented mainly by fragmentary dental and mandibular material. Here we describe a new deltatheroidan genus and species (Archetheridium sinense gen. et sp. nov.) based on a partial skeleton from the Early Cretaceous Jehol Biota. This specimen represents the earliest known unequivocal metatherian. The new specimen preserves a distinctive combination of deltatheroidan dental and mandibular features, supporting its deltatheroidan affinity. This discovery indicates that the initial diversification of deltatheroidans and metatherians occurred earlier than previously suggested. The specimen provides new evidence for the early establishment of metatherian dental morphology and faunivorous specialization during the Early Cretaceous. Together with other records of early therians in Asia, this finding supports the hypothesis that Asia may have been a centre of metatherian origin.
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