Obligatory disclaimer: real life sucks. Today is May 12,
2020, and so far, neither U.S. nor Canada are making much noise about ending
the lockdown/self-isolation/etc. The RF might’ve ended its’ period, for various
reasons, but now that Putin’s press-secretary got the COVID-19, I’ve no idea as
to what this country will do next, or rather – what this country’s president,
aka Vladimir Putin, will do.
…On the other side of the ocean, the Donald is escaping female
journalists – remind me, as to why he was not impeached before? Oh, because no
one in D.C. really wants it: not the Republicans, and not the Democratic
leadership in the person of Ms. Pelosi and co. USA! USA! …When will the
lockdown end?
On the other hand, let us talk about something else. How
about the koala, since we have talked about the kangaroos previously?
Now, the former is just as much a symbol of Australia as the
kangaroos are, but it is very different from them, and I am not just talking
about the obvious.
Take, for example, classification. By most conservative
standards, there are at least 4 to 6 species of ‘true’ kangaroos, and with all
of their cousins, there is a lot more. By contrast, there is only one koala species;
it is the last member of a dynasty of specialized eucalyptus leaf-eaters and
even by the marsupial standards, this beast is a rather dim bulb. Undoubtedly,
it makes up in part for its’ dimwittedness by being so adorably cute, (not
unlike Leo Fitz from AoS), but still. Leo Fitz is also a genius, you know!..
Putting AoS aside for
now, does the koala have any relatives? Aye, they are called the wombats, and you
can see one of them in one of ‘Brave Wilderness’ YouTube videos. The wombats,
(I believe that currently there are two or three species of them), don’t look
too similar to the koala; in fact, they’re its’ opposites in several important
areas – the koala lives in trees, the wombats on the ground, and in burrows;
the koalas are very noticeable, while the wombats aren’t so much; the koala
hides a nasty temper behind its’ plush toy looks, while the wombat is more
placid and can be tamed fairly easily, especially by marsupial standards; but!
Their lifestyles are similar, as both the koala and the wombats are solitary,
asocial herbivores, whereas the kangaroos small and especially big usually live
in family herds instead. Why?
One of the explanations is that the kangaroos are only very
distant relatives of the koala and the wombats; the koala might be the very basic
model of the marsupial evolution that would eventually lead to the modern
wombats, while the kangaroos belong to the second, completely separate branch
of the Diprotodont order, and their closest relatives are the possums.
No, you have read it correctly: the opossums are the shy,
mostly nocturnal, primarily arboreal marsupials of the American tropics, with
just the Virginian opossum living in the North America. The possums that have
no ‘o’ before the ‘p’ are their Australian counterparts – small to smallish
arboreal marsupials that often are active at night rather than during the day.
They do not really look like kangaroos-
-There are tree kangaroos, which look generally like the
rest of the kangaroos, but are usually discussed separately from the rest of
the roo family. Looks like the kangaroos’ evolution also involved an arboreal
stage sometime in the past. Why ‘also’? Because we are coming back to the
koala, which is the most arboreal member of its’ family branch of all the
members there, living and extinct. The latter includes the marsupial lions,
(the Thylacoleo group), and also the Diprotodonts and their relatives – the extinct
rhino-sized wombats. Put otherwise, the wombats, the koala and their extinct
relatives were the ‘robust’ herbivores, while the kangaroos and their
relatives, (including their own extinct giants, such as the Procoptodon), were
the speedy ‘gracile’ ones.
…The marsupial lions, of course, are a group apart, and not
just because they were the koalas’ closest relatives, (in the past, when there
were marsupial lions in Australia, there were also several species of the
koalas as well). They were the most efficient and the largest of carnivorous
marsupials, much more formidable than the Thylacine, (now also extinct, sadly –
at least in the canon), and the Tasmanian devil, (still existing, but clearly
needing human help to survive), and that was during the time when Australia’s
top carnivores were all giant reptiles – Megalania, (self-explanatory by now), Wonambi,
(a giant constrictor snake), Quinkana, (the last of the truly terrestrial
crocodiles of Earth), and so on. Put otherwise, unlike the placental mammals,
who got rid of their competition fairly quickly, by the end of Eocene or so,
the Australian marsupials, (and to a lesser extent – their South American
cousins), had to deal with both the giant flightless birds and the last of
truly giant reptiles; they are now gone for good, but there are gaps in the
Australian ecosystem, and not even the new, introduced, placental species can
repair it, (and as the Thylacine situation shows, it can very easily backfire
instead)…
Well, this is it for now. It’s due to those gaps and
extinctions at the end of the last Ice Age why we have only the kangaroos as authentically
large marsupial herbivores – the koala is too specialized a leaf-eater to
evolve further, (probably), and the wombats aren’t much larger than the modern
badgers are – their giant cousins did all the heavy eating. Ah well, time and
tide wait for no man or beast… See you all soon!
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