Department of Anatomy, Dartmouth Medical School, and Department of Anthropology, Dartmouth College, Hanover, New Hampshire 03755, USA.
J Hum Evol. 2010 Apr;58(4):338-52. doi: 10.1016/j.jhevol.2010.01.005. Epub 2010 Mar 11.
Following human arrival, Madagascar suffered well-documented megafaunal extinctions and widespread deforestation. Although humans are widely considered to be the primary cause of the extinctions, the relative contributions of climate change and human activities to this ecological transformation remain uncertain. Reconstructing the habitats of the giant lemurs of Madagascar can provide key information for understanding the evolutionary mechanisms involved in their extinction. In this study, I present a faunal analysis of the subfossil assemblage from Ankilitelo Cave, southwestern Madagascar. This assemblage documents the latest known occurrence of five species of extinct giant lemur, in association with abundant well-preserved small mammal remains. I compared the small mammal fauna at Ankilitelo with 27 extant Malagasy mammal communities spanning the range of Madagascar's habitat types. Similarities in species composition between modern communities and Ankilitelo were assessed using cluster analysis. Ecological similarities were examined by assigning each species to dietary, locomotor, activity pattern, and body size categories. Multiple discriminant analysis was then used to classify Ankilitelo relative to modern habitat types in Madagascar, based on the ecological structure of the subfossil fauna. Results indicate that the habitat surrounding Ankilitelo during the late Holocene was similar to the succulent woodlands of modern southwestern Madagascar. This suggests that approximately 500yr BP, these semi-arid habitats supported a subfossil lemur community that included the highly-suspensory Palaeopropithecus, and deliberate slow-climber Megaladapis, as well as Archaeolemur, Pachylemur, and Daubentonia robusta. In such environments, these giant lemurs would likely have been highly vulnerable to increasing human pressure in southwestern Madagascar.
人类抵达马达加斯加后，那里的巨型动物经历了有据可查的灭绝和广泛的森林砍伐。尽管人类被广泛认为是灭绝的主要原因，但气候变化和人类活动对这种生态转变的相对贡献仍不确定。重建马达加斯加巨型狐猴的栖息地，可以为理解导致它们灭绝的进化机制提供关键信息。在这项研究中，我对马达加斯加西南部安基利特罗洞的亚化石组合进行了动物群分析。该组合记录了五种已灭绝巨型狐猴的最新已知出现情况，同时还保存了大量完好的小型哺乳动物遗骸。我将安基利特罗的小型哺乳动物群与分布在马达加斯加各种栖息地类型的 27 个现存马达加斯加哺乳动物群落进行了比较。通过聚类分析评估了现代群落与安基利特罗之间的物种组成相似性。通过将每个物种分配到饮食、运动方式、活动模式和体型类别，检查了生态相似性。然后，基于亚化石动物群的生态结构，使用多元判别分析将安基利特罗与现代马达加斯加的栖息地类型进行分类。结果表明，全新世晚期安基利特罗周围的栖息地与现代马达加斯加西南部的肉质林地相似。这表明，大约在 500 年前，这些半干旱栖息地支持着一个亚化石狐猴群落，其中包括高度悬挂的古灵长类动物 Palaeopropithecus 和故意缓慢攀爬的巨型树懒 Megaladapis，以及 Archaeolemur、Pachylemur 和 Daubentonia robusta。在这样的环境中，这些巨型狐猴很可能容易受到马达加斯加西南部人类压力的增加的影响。
