Warburton Natalie M, Prideaux Gavin J
Centre for Climate-Impacted Terrestrial Ecosystems, Harry Butler Research Institute, Murdoch University, Australia.
Department of Earth and Planetary Sciences, Western Australian Museum, Kew Street, Welshpool, WA, Australia.
R Soc Open Sci. 2021 Mar 24;8(3):202216. doi: 10.1098/rsos.202216.
The macropodine kangaroo, , was first described in 1989 from a Pleistocene deposit within Mammoth Cave, southwestern Australia, on the basis of a few partial dentaries and maxilla fragments. Here, we recognize within the Pleistocene assemblages of the Thylacoleo Caves, south-central Australia, where it is represented by several cranial specimens and two near-complete skeletons, a probable male and female. We reallocate this species to the hitherto monotypic genus . differs from all other macropodid species by having a highly unusual pocket within the wall of the nasal cavity. It is distinguished from by having a longer, narrower rostrum, a taller occiput and a deeper jugal. is closest to in overall cranial morphology but is smaller and less robust. In most postcranial attributes, also resembles , including general limb robustness and the atypical ratio of 14 thoracic to five lumbar vertebrae. It is distinguished by the high mobility of its glenohumeral joints, the development of muscle attachment sites for strong adduction and mobility of the forelimb, and large, robust manual and pedal digits with strongly recurved distal phalanges. These adaptations resemble those of tree-kangaroos more than ground-dwelling macropodines. We interpret this to imply that was semiarboreal, with a propensity to climb and move slowly through trees. This is the first evidence for the secondary adoption of a climbing habit within crown macropodines.
大袋鼠科袋鼠于1989年首次根据澳大利亚西南部猛犸象洞穴内更新世沉积物中的几块部分齿骨和上颌骨碎片被描述。在此，我们在澳大利亚中南部袋狮洞穴的更新世组合中识别出了它，在那里有几个颅骨标本和两具近乎完整的骨骼代表它，可能是一雄一雌。我们将这个物种重新归类到迄今单型的属中。该物种与所有其他大袋鼠科物种的不同之处在于鼻腔壁内有一个非常不寻常的腔室。它与……的区别在于有一个更长、更窄的吻部、更高的枕骨和更深的颧骨。在整体颅骨形态上，它与……最接近，但体型较小且不那么粗壮。在大多数颅后特征方面，它也与……相似，包括一般肢体的粗壮程度以及14个胸椎与5个腰椎的非典型比例。它的特征在于其肩肱关节的高灵活性、用于前肢强力内收和活动的肌肉附着点的发育，以及大而粗壮的手和脚指，远端指骨强烈弯曲。这些适应性特征与树袋鼠的更相似，而不是与地栖大袋鼠科动物的相似。我们认为这意味着它是半树栖的，有攀爬和在树上缓慢移动的倾向。这是有袋类动物中次生采用攀爬习性的首个证据。
