Excavations at Kanapoi in north-western Kenya have yielded the most numerically abundant and taxonomically diverse early Pliocene (4.19 Ma) terrestrial small mammal assemblage known from Kenya. A minimum of 15 species are reported, including soricids, sengis, leporids, and rodents: all taxa are referable to extant genera, with the exception of the murine rodent, Saidomys. The majority of the terrestrial small mammals are derived from a bone bed at Nzube's Mandible Site, closely associated with the holotype mandible of Australopithecus anamensis. A smaller number were surface-collected or obtained from screening at several other sites, including the Bat Site. Most small mammals from Nzube's Mandible Site and the Bat Site likely represent prey accumulated as regurgitated pellets from owls, in particular barn owls or giant eagle owls. The small mammal fauna is dominated by the spiny mouse, Acomys: the next most commonly recovered taxa are the multimammate mouse, Mastomys, and the African gerbil, Gerbilliscus. Comparisons of the Kanapoi fauna to other eastern African late Miocene-Pliocene (and one Pleistocene) faunas at the generic level suggest the greatest similarity is to Lemudong'o, Kenya, and Omo B and Aramis, Ethiopia. Further similarities with other localities such as Laetoli, Tanzania, and Hadar, Ethiopia, suggest the existence of a corridor for dispersal along the East African Rift Valley between Ethiopia, Kenya, and Tanzania in the early Pliocene. Further comparisons of the relative abundances of individuals in different families (or subfamilies) emphasize the distinctiveness of the Kanapoi small mammal fauna. The Kanapoi fauna is likely derived from a heterogeneous but relatively arid environment.

在肯尼亚西北部的Kanapoi进行的发掘产生了数量最多，分类学上最多样化的早期上新世（4.19 Ma）陆生小型哺乳动物组合，据肯尼亚人所知。据报道，至少有15种，包括茄科类，僧伽虫类，类脂蛋白类和啮齿类：除鼠类啮齿类动物“赛多密斯”外，所有类群均指现存属。大多数陆地上的小型哺乳动物均来自恩祖贝下颌骨部位的骨床，该骨床与南方古猿整形下颌骨密切相关。在其他几个地点，包括蝙蝠场，从地面收集或通过筛选获得的数量较少。来自Nzube下颌骨站点和蝙蝠站点的大多数小型哺乳动物很可能代表从猫头鹰，尤其是谷仓猫头鹰或巨型雕中反刍的颗粒状积累的猎物。小型哺乳动物动物区系由多头老鼠Acomys主导：其次是最常见的分类群，即大型哺乳动物Mastomys和非洲沙鼠Gerbilliscus。。将Kanapoi动物区系与其他东部非洲中新世-上新世（和一个更新世）动物区系进行通用比较，表明最大的相似之处是与肯尼亚的Lemudong'o和埃塞俄比亚的Omo B和Aramis。与其他地方（例如坦桑尼亚的Laetoli和埃塞俄比亚的哈达尔）的进一步相似之处表明，在上新世初期，埃塞俄比亚，肯尼亚和坦桑尼亚之间的东非大裂谷之间存在着一条分散走廊。进一步比较不同家庭（或亚家庭）中个体的相对丰度，强调了Kanapoi小哺乳动物动物区系的独特性。Kanapoi动物区系可能来自异质但相对干旱的环境。