The Early Miocene sites of Napak (Uganda), which have been prospected by the Uganda Palaeontology Expedition since 1985, have yielded abundant fossil remains, including a rich and diverse rodent fauna. Ever since the work of Lavocat (1973) on the East African Miocene rodents, which focused mainly on the Kenyan remains (but included some material from Napak discovered by Bishop during the 1950s and 1960s), few studies have been made on the Ugandan specimens. This lack provides motivation for further study of Napak micro-mammals, especially the abundant rodents, which were collected at five sites, Napak IV, V, XV, XXX and XXXI. The fossils described here are attributed to six species representing four families: Afrocricetodontidae (Afrocricetodon songhori, Protarsomys macinnesi), Myophiomyidae (Myophiomys arambourgi), Kenyamyidae (Simonimys genovefae, Kenyamys mariae) and Sciuridae (Vulcanisciurus africanus). Comparison of the dentition of extant and extinct taxa allows us to propose dietary hypotheses (granivory, herbivory and omnivory) for these rodents. In addition, the fossil rodents associated with other fauna from the same localities suggest a more-or-less dense forest environment with clearings, and the probable presence of a humid climate at the time of deposition.

1985年以来，乌干达古生物学考察队对纳帕克（乌干达）的中新世早期遗址进行了考古发现，产生了丰富的化石遗骸，其中包括丰富多样的啮齿动物。自从Lavocat（1973）在东非中新世啮齿动物上开展工作以来，该工作主要集中在肯尼亚的遗骸上（但其中包括Bishop在1950年代和1960年代发现的Napak的一些材料），但对乌干达标本的研究很少。这种缺乏为进一步研究Napak微型哺乳动物，尤其是大量啮齿动物提供了动力，Napak微型哺乳动物是在Napak IV，V，XV，XXX和XXXI五个地点收集的。这里描述的化石归因于代表四个科的六个物种：非洲A科（Afrocricetodon songhori，Protarsomys macinnesi），Myophiomysae（Myophiomys arambourgi），Kenyamyidae（Simonimys genovefae，Kenyamys mariae）和Sciuridae（Vulcanisciurus africanus）。比较现存和灭绝类群的牙列，使我们能够为这些啮齿动物提出饮食假说（食草，食草和杂食动物）。此外，与来自相同地区的其他动物相关的化石啮齿动物表明，森林环境或多或少带有空地，并且在沉积时可能存在潮湿的气候。