Acrobatidae

Abstract: The feathertail glider (Acrobates pygmaeus) is a mouse-sized marsupial that can cling to and run on smooth vertical panes of glass. To understand this remarkable ability, a comparative histological...

Abstract: The Australasian marsupial order Diprotodontia includes ten extant families that are grouped into the suborders Vombatiformes (koalas and wombats), Macropodiformes (kangaroos and allies), and Phalangeriformes (possums and gliders). We investigated interfamilial relationships using mitochondrial 12S rRNA, valine tRNA, and 16S rRNA gene sequences. Our results support the monophyly of both Vombatiformes and Macropodiformes, but not Phalangeriformes. Among possums and gliders, there was strong support for a petauroid clade that includes Pseudocheiridae (ringtail possums), Petauridae (sugar glider, striped possums), Acrobatidae (feathertail possums), and the monotypic family Tarsipedidae, which is represented by the highly specialized and autapomorphic honey possum (Tarsipes rostratus). Other prior hypotheses for the phylogenetic placement of the honey possum were rejected by statistical tests. The inclusion of the honey possum within Petauroidea suggests that derived ultrastructural features of Tarsipes' spermatozoa evolved independently in Tarsipes versus polyprotodont Australasian marsupials.

Abstract: Acrobates pygmeus is a small arboreal marsupial thought to be restricted to eastern Australia, from southeastern South Australia to the tip of Cape York Peninsula in northern Queensland. Here I discuss the possibility that the species also occurs in New Guinea, based on two poorly-localized museum specimens (in London and Stockholm) supposedly collected from that island. Key words: Feather-tailed glider, Acrobates pygmeus, Acrobatidae, marsupials, New Guinea

Abstract: The Marsupial feathertail glider has a unique set of morphological, anatomical and behavioural features that make it a promising model for study of primate evolution. Among them it has many locomotor adaptations to arboreal life, such as diagonal gait of movements, gliding, fast climbing and running along branches. These ecological and behavioural specialisations could result in differences in anatomy of the brain systems involved in their integration. It is well acknowledged that dopaminergic neurons are involved in motor control, motivation and cognition. Due to the fact that there are no data on morphological organisation of dopaminergic system in the midbrain of this species, we decided to investigate it using immunohistochemical and quantitative methods. Our study showed that the general distribution and characteristics of the dopaminergic cells within midbrain nuclei of the pygmy acrobat is similar to that in other species, but it lack the substantia nigra compact part — ventral tier and “tail” of the substantia nigra subnuclei. This study provides the first description of the dopaminergic cells and nuclei in the midbrain of the feathertail glider and we hope it will start interest in the neurobiology of this species.