the answer!

Both wombats and koalas have this hard pad of cartilage across their lower back. The wombat uses it to block the entrance to their burrow when a predator tries to get in, the koala leans back on it on a branch.
How can something so odd be used so differently? Mother nature is awesome

[Wylie]

Well that would make some of these postures a little more comfortable.... but!

[KoalaGardens🐨]

@pusspup you mean butt? 😂

[Babs]

Well there you go, a koala fact I didn't know, so interesting

[Gosia]

Wow, learned something new. Thank you

[Fr1da]

wow they do have strong backs !

[Esther Rosenberg]

Ha! thanks for the answer ( finally lol) So interesting.

[Carole Sandford]

Interesting, didn’t know that.

[Diana]

How very interesting and yet rather unusual!

[Mags]

I wish I had that. Cute capture!

[Joanne Diochon]

I think Koala’s would need some kind of padding there, considering the odd positions they get in while sleeping.

[mittens (Marilyn)]

I'm enjoying your interesting information.

[wendy frost]

Very useful part to the body for both of them and quite an amazing fact.

[Beryl Lloyd]

Amazing isn't it , so much to learn , !!

[tony gig]

Wonderful...fav

[Ann H. LeFevre]

How interesting- and who would have guessed that? Fun fact for sure!

[Rick]

Great capture in interesting information.

[Shutterbug]

Fascinating. I never would have guessed that. I’m learning a lot from your series. I think that cartilage must not have any pain nerves in it.

[Lou Ann]

Ah ha! Now I understand how they can perch where they do!

[Desi]

Wow that's incredible. I knew about the wombats having a hard pad of cartilage but had no idea Koalas have one too. So interesting to learn so many little facts