Mistretta Brittany A, Giovas Christina M, Weksler Marcelo, Turvey Samuel T
Department of Anthropology, University of Florida, Gainesville, FL 32611, USA Environmental Archaeology Program, Florida Museum of Natural History, FL 32611, USA.
Zootaxa. 2021 Apr 7;4951(3):zootaxa.4951.3.2. doi: 10.11646/zootaxa.4951.3.2.
The Lesser Antillean island chain in the eastern Caribbean formerly supported a diverse rodent fauna including multiple endemic genera of oryzomyine rice rats. The Caribbean rice rats are now all extinct, with most island populations known only from Holocene palaeontological and zooarchaeological material and with many remaining taxonomically undescribed. Rice rat material is reported from several pre-Columbian Ceramic Age (late Holocene) archaeological sites on the Grenada Bank, including sites on Grenada and Carriacou, but the taxonomic identity and diversity of the Grenada Bank rice rats has remained uncertain. We provide a morphology-based description of rice rats from Grenada and Carriacou, and analyze their phylogenetic and biogeographical affinities to other Caribbean and mainland Neotropical oryzomyines. We recognize two taxa from the Grenada Bank: we describe the new species Megalomys camerhogne from Pearls (Grenada), representing the largest-bodied member of the extinct endemic Caribbean genus Megalomys, and we refer smaller-bodied oryzomyine material from Pearls and Sabazan (Carriacou) to the widespread extant Neotropical species Zygodontomys brevicauda. Body size variation within Megalomys correlates with island bank area and might thus reflect historical rather than modern biogeography. Zygodontomys specimens from the Grenada Bank fall within the upper end of size variation in extant populations and may constitute an example of 'island gigantism', but it is possible that occurrence of this widespread species on the Grenada Bank might reflect prehistoric human-mediated translocation. We predict further endemic Caribbean rice rat taxa remain to be discovered, including a possible species of Megalomys on the neighbouring island of St. Vincent.
东加勒比海的小安的列斯群岛曾经拥有丰富多样的啮齿动物群，包括多个稻鼠属的特有属。加勒比稻鼠现已全部灭绝，大多数岛屿种群仅见于全新世古生物学和动物考古学材料，且许多仍未得到分类描述。在格林纳达浅滩的几个前哥伦布时期陶瓷时代（晚全新世）考古遗址中发现了稻鼠材料，包括格林纳达和卡里亚库的遗址，但格林纳达浅滩稻鼠的分类身份和多样性仍不确定。我们对来自格林纳达和卡里亚库的稻鼠进行了基于形态学的描述，并分析了它们与其他加勒比和新大陆热带稻鼠的系统发育和生物地理亲缘关系。我们识别出格林纳达浅滩的两个分类单元：我们描述了来自珍珠岛（格林纳达）的新物种卡梅霍格巨稻鼠，它是已灭绝的特有加勒比巨稻鼠属中体型最大的成员，我们将来自珍珠岛和萨巴赞（卡里亚库）的体型较小的稻鼠材料归为广泛分布的现存新大陆热带物种短尾稻鼠。巨稻鼠属内的体型变化与岛屿浅滩面积相关，因此可能反映的是历史而非现代生物地理学。来自格林纳达浅滩的短尾稻鼠标本处于现存种群体型变化的上限，可能是“岛屿巨型化”的一个例子，但这个广泛分布的物种出现在格林纳达浅滩也有可能反映了史前人类介导的迁移。我们预测仍有待发现更多加勒比特有稻鼠分类单元，包括在邻近的圣文森特岛上可能存在的巨稻鼠物种。
