干旱区生态环境知识资源中心

Twenty-two terrestrial and over 20 marine mammal faunas are currently recognized in the fossil record of Victoria, representing one of the most complete records of mammal evolution in Australia. Although the earliest recorded terrestrial mammals come from the Early Cretaceous, the majority of the faunas are concentrated in the Pliocene and Pleistocene, whereas the marine mammal record spans the Late Oligocene-Holocene. Despite the generally fragmentary nature of the fossil remains, many of the faunas are diverse and offer insights into the changes in palaeoecology and palaeoenvironmental conditions of the region over time. The terrestrial mammal faunas follow the global trend with the appearance of more arid-adapted species in the late Pliocene; however, a number of Pliocene-Pleistocene coastal sites indicate the continued presence of wet forest refugia, with several relict species occurring in the Early Pleistocene. Most of the faunas are well dated, providing a basis for the production of a biostratigraphic framework, essential for the more accurate dating of mammals in Australia. Two new diverse mammal sites, Childers Cove and Portland, are a welcome addition to the Pliocene records of both terrestrial and marine mammals. Marine mammal research is only in its early stages, but the Victorian record is fundamental in understanding the evolution of cetaceans in the southern oceans. The known diversity of species has increased substantially as a result of recent research. Some well-preserved specimens, including complete skulls, have implications for cetacean systematics, including basal mysticetes. However, much more work needs to be focused on the cataloguing, preparation, description and interpretation of the faunas to take full advantage of this excellent record.