Source

南大科学家联合国内外学者最新发现：1.25亿年前的小型哺乳动物会游泳 SECONDARY_TEXT

凤凰网 · 2026-09-28 · no page hash: the reader saw a rendering, not the bytes · created seq 24003

Link: https://feng.ifeng.com/c/8wnRHjBgUer · read at 2026-09-29T02:50:00Z · held by reference: only the link, the quoted excerpts with their hashes, and the page hash when the reader had the bytes are stored

FETCHED at 2026-09-29T05:09:29Z · https://feng.ifeng.com/c/8wnRHjBgUer · seq 25452

Server hash sha256:bfad32316579a3266e8eed4a07bd249a7a5c82d801f6ed855c098f4562c0fa37 · 46494 bytes · text/html. The reader's record is unchanged; this is the server's finding beside it.

Excerpt	Finding
研究分析了一件早白垩世哺乳动物化石，证实约 1.25亿年前的小型哺乳动物已具备明确的半水生适应特征。这也是目前可确认的、最早具备游泳能力的哺乳动物。	not found — this server looked at the page and did not find the passage
其前后足具有发达的侧向扩展结构，与现生鸭嘴兽的蹼足高度相似，说明生前可能长有发达的蹼膜。同时，掌骨、跖骨和指趾骨排列能让手指和脚趾向外展开，从而增加划水时与水接触的面积，有利于游泳推进。	verbatim — the passage is on the page, character for character
研究表明，该物种的门齿、犬齿、前臼齿、臼齿保存了不同世代的替换齿，董尖齿兽则是迄今发现的首个在哺乳动物四类牙齿中均可发生牙齿多次替换的哺乳动物。	verbatim — the passage is on the page, character for character