NEW AUSTRALIAN OLIGOCENE TO MIOCENE RINGTAIL POSSUMS (PSEUDOCHEIRIDAE) AND REVISION OF THE GENUS MARLU

Abstract:  Four genera of extinct ringtail possums have been reported from Australian Oligocene to Miocene sediments since 1987. The genus Marlu was described from two species, M. kutjamarpensis and M. praecursor (Woodburne, Tedford and Archer), from the Miocene Kutjamarpu Local Fauna (Leaf Locality) and late Oligocene Wadikali Local Fauna respectively, of northern South Australia. New fossil material referable to this genus has been collected from the Leaf Locality and the Oligocene to Miocene Riversleigh World Heritage Area in northwest Queensland. Three new species, Marlu karya sp. nov. from middle Miocene Riversleigh local faunas and Marlu syke sp. nov. and Marlu ampelos sp. nov. from the Leaf Locality as well as early to middle Miocene Riversleigh local faunas are described. A revision and rediagnosis of the genus and published species are made following the re-examination of referred material in conjunction with the new material. Marlu is characterized by simple dentition and synapomorphies with extant pseudocheirids such as a conjoined postmetacristid and preentocristid on m1 and the loss of the entostylid ridge. New material from middle Miocene Riversleigh deposits has been referred to M. kutjamarpensis , extending the known distribution and age of that species. Re-examination of M. praecursor has revealed the presence of a small m1 entostylid ridge, contributing further to differences between M. praecursor and all other Marlu species and raising the possibility that Marlu is paraphyletic. The new material does not contradict a sister group relationship between ' Marlu ' (excluding M. praecursor ) and the Pliocene–Pleistocene genus Pseudokoala. Homology of the pseudocheirid m1 protostylid identified in species of Paljara , Pildra and Marlu with that observed in extant species is reconsidered. The 'protostylid' of the extinct genera is herein described as the buccal stylid.     

Bark Consumption by the Painted Ringtail (Pseudochirulus forbesi larvatus) in Papua New Guinea1

We documented bark consumption by painted ringtails (Pseudochirulus forbesi) and other arboreal marsupials at Mt. Stolle, Papua New Guinea. Evidence consisted of scratch marks on the boles of trees in conjunction with the removal of all moss and direct sightings of animals eating bark. Only 43 trees ≥10 cm diameter at breast height (DBH) of 19 species showed signs of consumption at the study site; five of these species were confirmed by direct sighting to be consumed by painted ringtails. We sought to determine if bark of these trees contained important dietary minerals. Analyses showed that calcium and potassium, individually and combined, were significantly more abundant in eaten versus uneaten trees of the same species. On average, eaten trees showed 4.7 and 2.2 times the amount of these minerals, respectively, as found in uneaten trees. Adult males were more likely than adult females or juvenile males to be captured at eaten trees than away from them. Two species of Syzygium and one species of Sloanea were highly selected for bark consumption, but not all trees of a species were eaten; rather, particular individuals of these species were preferred. We conclude that bark appears to be an important source of calcium and potassium, and speculate on the relationship between the limited availability of these special trees and the social behavior of painted ringtails.