Our friend Will Downs liked to travel; both within the natural and cultural geographies of this world and within the abstract geographies of the past and future. He wanted to go everywhere and pretty much did. Precambrian river gorges, Triassic tribal deserts, Miocene tropical volcanoes, and even densely urban, modern civilizations were all Will’s habitats.
This paper uses our memories of Will as an opportunity to bring together descriptions of fossil material from just three of the places where he worked: Uganda, and the Potwar Plateau and Sulaiman Ranges of Pakistan. While these fossils would ordinarily not have been described together, they do have a commonality. They are early representatives of one of the great mammalian radiations, the Oligocene to Early Miocene radiation of the ruminants. The ruminant radiation gave rise to six modern families with nearly 200 extant species, and it also produced an abundance of extinct species and higher level taxa. However, most of what we know of this radiation is based on taxa from the temperate Oligocene and Miocene of North America, Europe, and central Asia, with little being known of contemporaneous ruminants from tropical southern Asia or Africa, which are now the sites of the greatest species diversity. In this paper we describe fossil material from the Early Miocene of Uganda and the Oligocene through Early Miocene of southern Asia, and, particularly in the case of Pakistan, this adds a new element to our understanding of the evolutionary history of early ruminants.
The material we discuss was collected during fieldwork by several of us during the past 15 years, and in most cases represents species that are poorly known. The fossils represent at least eight species belonging to six major groups. Seven species come from Pakistan and one from Uganda. The scope of the study is limited in two ways. First, we only discuss new material and do not attempt to reanalyze older collections, which in East Africa are quite extensive. Such an undertaking would be too much for the limited time available and is only significant in the case of the East African record. Secondly, with the exception of one species, the taxa discussed in this paper are all members of the Pecora. Tragulids are also very well represented in these collections, perhaps with as many as seven additional species in two genera from the Oligocene and Early Miocene. The material, however, requires a thorough study of the very large and species rich Middle and Late Miocene collections of tragulids from the Potwar Plateau and East Africa. Tragulids are thus not considered here.