An osteology-based appraisal of the phylogeny and evolution of kangaroos and wallabies (Macropodidae: Marsupialia)

Abstract

Macropodids are the most diverse group of marsupial herbivores ever to have evolved. They have been the subject of more phylogenetic studies than any other marsupial family, yet relationships of several key clades remain uncertain. Two important problem areas have been the position of the merrnine (Lagostrophus fasciatus) and the phylogenetic proximity of tree-kangaroos and rock-wallabies. Our osteological analysis revealed strong support for a plesiomorphic clade (Lagostrophinae subfam. nov.) containing Lagostrophus and Troposodon, which is likely to have originated in the early Miocene. The extinct short-faced kangaroos (Sthenurinae) emerged in the middle Miocene as the sister lineage to a clade containing all other living kangaroos and wallabies (Macropodinae). New Guinea forest wallabies (Dorcopsini trib. nov.) are the most plesiomorphic macropodines; the other two main lineages include tree-kangaroos and rock-wallabies (Dendrolagini), and 'true' kangaroos and wallabies (Macropodini). These phylogenetic outcomes are broadly consistent with the results of recent molecular studies, although conflicts remain over the relative positions of some macropodins (e.g. Setonix, Onychogalea, and Wallabia). Given the presence of derived dendrolagins and macropodins in early Pliocene localities, it is probable that most macropodine genera originated in the late Miocene. Key functional-adaptive trajectories within the craniodental and locomotory systems of the dominant macropodid lineages represent varying responses to the spread of drier, open habitats following the Miocene Climatic Optimum.

Revision of basal macropodids from the Riversleigh World Heritage Area with descriptions of new material of Ganguroo bilamina Cooke, 1997 and a new species

“…In contrast, Prideaux and Warburton (2010), who only included in their analysis Ganguroo bilamina and 'Nowidgee matrix', recovered 'N. matrix' as the sister group to all macropodids (lagostrophines, sthenurines and macropodines), and G. bilamina as the sister group to sthenurines and macropodines with stronger support values (bootstrap = >50%).…”

“…matrix' as the sister group to all macropodids (lagostrophines, sthenurines and macropodines), and G. bilamina as the sister group to sthenurines and macropodines with stronger support values (bootstrap = >50%). It is noteworthy that Prideaux and Warburton (2010) completely rescored G. bilamina and 'N. matrix' based on type material assigned to both species by Cooke (1997a), but they did include postcranials assigned incorrectly to G. bilamina by Kear et al (2001a).…”

“…While the matrix of Prideaux and Warburton (2010) is more recent, they acknowledged that their principle purpose was to investigate the relationship of bilophodont macropodids, and therefore not suitable to analyse more basal forms. They mentioned that their matrix would require an extensive increase in characters and additional outgroups before it could be used for that purpose.…”

Anatomical adaptations of the hind limb musculature of tree-kangaroos for arboreal locomotion (Marsupialia : Macropodinae)

“…Tree-kangaroos evolved during the Late Miocene from a common ancestor with rock-wallabies (Flannery 1989;Prideaux and Warburton 2010). Extinct plesiomorphic treekangaroos Bohra spp.…”

Four mammal fossil calibrations: balancing competing palaeontological and molecular considerations

“…The earlier fossils, although including crown marsupials, do not clearly fit into modern orders (Beck et al, 2008), while many calibrations derived from the latest Oligocene faunas (e.g., Vombatiformes and Phalangeroidea) are expected to substantially postdate the actual divergence times (Meredith et al, 2009, Black et al, 2012. In contrast, records from the latest Oligocene to Early Miocene include numerous 'transitional' macropodoids morphologically close to expectations for the kangaroo-potoroo divergence (Prideaux and Warburton, 2010). Hence, Macropodoidea likely provides one of the most informative calibrations above the family level among Australian marsupials.…”