Galloping kangaroos!

When the Riversleigh treasure trove of fossils was discovered in 1976 in northern Queensland, Australia, few could have conceived of, and fewer would have predicted, the wondrous wildlife it would reveal, not to mention the lush rainforest world in which they lived. The freshwater limestone deposits from which the relics have been gouged, blasted, and chiseled were laid down between about 25 and 15 million years ago (over forty million years later than dinosaurs), a grassless period of time in Australia. In recent decades an entire catalog of fascinating creatures which munched on fruits, leaves, invertebrates and each other - but not grass - has come to light. Included in the line-up are "box-headed" crocodiles that may have climbed trees, 800 pound birds, toothed platypuses (the living species has no teeth), dozens of bat species, and pouched marsupials galore. The marsupials include bandicoots, possums, kangaroos, koalas, diprotodontids (wombats), marsupial "lions", and some difficult-to-place creatures given names such as Thingodonta and Weirdodonta by playful bearded paleontologists. All are now extinct. One of the remarkable facts uncovered is that these creatures did not all live at the same time. As Kear and others put it,

The vast quantities of material discovered thus far indicate several stratigraphically distinct local faunas of freshwater fish, amphibians, reptiles, birds, and mammals (Journal of Paleontology, Nov/Dec 2007, p. 1147).

In simple terms, they are saying that different assemblages of creatures lived at different times! Wow! What a concept. But hey, in this blog I'm not trying to give you an exhaustive record of what lived when. Rather, I want to look at one recently-revealed illustration of another amazing fact about

the ancient kinds - though most can be put in the same general grab bag as living species, they nevertheless differed markedly from living analogues.

Enter, stage left, Nambaroo gillespieae, a "kangaroo" whose near-complete skeleton was found in the 1990s but the description of which was not published until the latest issue of the Journal of Paleontology. In brief, Nambaroo differs considerably from the stereotypical modern "hopper" in the way it moved. Skeletal features suggest it was able to climb trees or at least to negotiate uneven terrain, albeit clumsily; though not revolutionary inasmuch as even today some species of tree kangaroo do the same, the ancientness of Nambaroo suggests that back in those days climbing was normal and hopping awaited the future for its heyday.

Though the authors appropriately emphasize that they intend to speak only of Nambaroo's "possible locomotory habits" - as distinct from jumping up and down and making a loud noise about the revolutionary nature of this roo's locomotion - those who read their paper and interview one or other of the authors all seem to agree that this was a roo with a difference. Its forelegs suggest it tore off leaves or fruit from trees; its hind legs suggest that, instead of hopping along on two legs like today's more respectable species, Nambaroo felt more at home using all four legs and that its locomotion could better be described as involving bounding or galloping than hopping. In short, Nambaroo was designed for a different environment than today's roos are. Rather than providing the least semblance of evidence for descent by modification, this ancient species illustrates yet again the limitlessness of the Father of all mankind for originality of thought and powers of creation. What a god is the One True God.