伦敦大学学院科学家在《科学进展》发表的一项最新研究指出，鳄鱼及其亲属之所以能在6600万年前导致非鸟类恐龙灭绝的小行星撞击事件中幸存，关键在于其对温暖环境的偏好使其栖息于赤道附近的热带避难所 1。这项由地球科学系博士阿尔菲奥·亚历山德罗·基亚伦扎（Dr. Alfio Alessandro Chiarenza）主导的研究分析了超过7000个化石以及400多个现存和已灭绝物种的记录，并重建了跨越2.45亿年的地球气候和地理模型 1。虽然小行星撞击后阳光减少可能导致全球气温下降，但模拟显示，即使阳光减少5%或10%，赤道附近的温暖区域仍适合鳄鱼亲属生存；尽管若阳光减少15%则不再适宜，但研究者认为这种极端情况发生的可能性较低 1。
研究还探讨了古代鳄类在不同地质时期的适应性演变及现代环境变化带来的威胁。在白垩纪热极事件期间（约9400万年前），部分鳄类分支进化出了耐受更高温度的能力，而在约3400万年前的澳大利亚，一组已灭绝的鳄鱼适应了日益干旱的环境 1。回溯至始新世早期（约5000万年前），当时全球平均气温比今天高约10°C，鳄鱼亲属曾广泛分布至北美、欧洲甚至南极洲等高纬度地区 1。针对当前的保护形势，菲利普·曼尼翁教授（Philip Mannion）指出，道路、农田和城市造成的现代栖息地破碎化限制了物种向适宜温度区域迁移的能力，这对鳄鱼亲属应对气候变化构成了潜在威胁 1
Scientists from University College London (UCL) published findings in Science Advances on October 30, 2026, explaining why crocodiles and their relatives survived the mass extinction event 66 million years ago that wiped out non-avian dinosaurs. 1 The study attributes this survival primarily to the animals’ preference for warm environments, which allowed them to retreat to tropical refuges near the equator when global conditions deteriorated following the asteroid impact. 1 Led by Dr. Alfio Alessandro Chiarenza of UCL Earth Sciences, the research team analyzed more than 7,000 fossils and records from over 400 living and extinct species to reconstruct Earth’s climate and geography across 245 million years. 1
The modeling results indicate that even if sunlight had decreased by 5% or 10% due to the impact’s atmospheric effects, equatorial regions would have remained suitable habitats for crocodylomorphs. 1 While a 15% reduction in sunlight was simulated as making these areas uninhabitable, the researchers note that such an extreme scenario is considered unlikely. 1 In contrast to the severe contraction of suitable habitats for non-avian dinosaurs, the warmth retained at the equator provided a critical sanctuary for crocodile ancestors during the K-Pg extinction event. 1
Beyond the extinction event, the study highlights how ancient climatic shifts shaped crocodile evolution and distribution. 1 During the Early Eocene approximately 50 million years ago, when global temperatures were about 10°C higher than today, crocodile relatives thrived in high-latitude regions including North America, Europe, and Antarctica. 1 Conversely, during the Cretaceous Thermal Maximum around 94 million years ago, certain lineages evolved mechanisms to tolerate even higher temperatures. 1 About 34 million years ago in Australia, a distinct group of now-extinct crocodiles adapted to increasingly arid conditions. 1
Professor Philip Mannion emphasizes that modern environmental changes pose different challenges than those faced by ancient ancestors. 1 He notes that habitat fragmentation caused by roads, farmland, and urban development currently restricts the ability of crocodile species to migrate toward areas with suitable temperatures. 1 This constraint threatens their resilience against contemporary climate change, despite their historical success in surviving major planetary upheavals. 1
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