Rare Fossilized Egg Reveals Secrets of Ancient Mammal Ancestors
罕見化石蛋揭示古代哺乳動物祖先的秘密
A groundbreaking discovery published in the journal PLOS One has unveiled a 250-million-year-old fossilized egg, providing the first definitive evidence that ancient mammal ancestors were egg-layers.
一項發表於《PLOS One》期刊的突破性發現揭示了一顆二點五億年前的化石蛋，提供了古老哺乳動物祖先為卵生動物的首個確鑿證據。
The specimen, containing a curled-up embryo of the tusked, pig-like Lystrosaurus, was found in South Africa’s Karoo Basin.
該標本在南非的卡魯盆地（ㄎㄚㄌㄨㄆㄣˊㄉㄧˋ）發現，內部含有捲曲的長牙、外貌像豬的李氏獸（ㄌㄧˇㄕˋㄕㄡˋ）胚胎。
Because these ancient creatures likely produced soft-shelled, leathery eggs, the fossils rarely survived decay, leaving scientists puzzled for over 150 years.
由於這些古老生物產下的蛋可能具有柔軟的革質蛋殼，化石難以保存，讓科學家困惑了一百五十多年。
Using advanced synchrotron X-ray CT scanning, researchers finally peered inside the fossil to confirm its contents.
研究人員利用先進的同步輻射（ㄊㄨㄥˊㄅㄨˋㄈㄨˊㄕㄜˋ）X射線斷層掃描技術，終於窺探化石內部並確認了其內容物。
This discovery settles a long-standing debate, proving that early mammalian ancestors relied on oviparous reproduction.
這項發現解決了長久以來的爭論，證實早期哺乳動物祖先依賴卵生進行繁殖。
The Lystrosaurus was a resilient survivor that thrived after the End-Permian extinction.
李氏獸是在二疊紀（ㄦˋㄉㄧㄝˊㄐㄧˋ）末期大滅絕後繁盛的強韌倖存者。
These eggs helped embryos resist drying out in harsh, arid conditions and produced precocial hatchlings, which could fend for themselves shortly after birth.
這些蛋幫助胚胎在嚴酷、乾燥的環境中抵抗乾涸，並能孵化出早熟的幼體，使其出生後不久就能自給自足，進而減少對親代持續照顧的需求。
Beyond identifying reproductive traits, this study offers fresh perspectives on how species build resilience during environmental crises, drawing parallels to modern biodiversity challenges.
