The macropodine kangaroo, Wallabia kitcheneri, 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 W. kitcheneri 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 Congruus. Congruus kitcheneri differs from all other macropodid species by having a highly unusual pocket within the wall of the nasal cavity. It is distinguished from C. congruus by having a longer, narrower rostrum, a taller occiput and a deeper jugal. Congruus is closest to Protemnodon in overall cranial morphology but is smaller and less robust. In most postcranial attributes, Congruus also resembles Protemnodon, 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 C. kitcheneri 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.

大袋鼠袋鼠Wallabia kitcheneri于1989年首次在澳大利亚西南部猛Ma洞内的一个更新世沉积物中被描述出来，其基础是一些局部的牙齿和上颌骨碎片。在这里，我们在澳大利亚中南部的Thylacoleo洞穴的更新世组合中认识到W. kitcheneri，那里有几个颅骨标本和两个接近完整的骨骼，可能是雄性和雌性。我们将这种物种重新分配到迄今为止的单型属Congruus。Congruus kitcheneri与所有其他巨足类动物不同，鼻腔壁上有一个非常不寻常的口袋。有别于C. congruus通过更长，更窄的讲台，更高的枕骨和更深的法齿。Congruus最接近平面袋鼠在整个颅形态，但更小，更坚固。在大多数颅后属性中，Congruus也类似于Protemnodon，包括一般的肢体健壮性和14胸椎与5腰椎的非典型比率。它的特点是其肱肱关节的高活动性，发达的肌肉附着位点，强壮的前肢内收性和活动性以及手腕和足趾大而健壮的远端指骨均弯曲。这些适应措施比树袋鼠更适合于树栖袋鼠，而不是栖于地面的大脚鸟。我们将此解释为暗示C. kitcheneri是半树状的，有攀爬和缓慢穿过树木的倾向。这是在树冠巨足类动物中次生采用攀爬习性的第一个证据。