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Re: Did giant kangaroos walk more like dinosaurs?



Understood, of course...


I was looking for a way to sneak an interesting non-dino/non-Mesozoic
paper on the DML,  and intended a bit of a twist on the early
reconstructions of Hadrosaurus and Laelaps [Dryptosaurus] as
kangaroo-like critters....

See

http://ephemeralnewyork.wordpress.com/2014/09/22/the-lost-dinosaurs-buried-under-central-park/


Another link about the new paper with a short video...

https://www.thedodo.com/giant-one-toed-rabbit-faced-sl-765797764.html

On Wed, Oct 15, 2014 at 12:44 PM, Mallison, Heinrich
<Heinrich.Mallison@mfn-berlin.de> wrote:
> Giant cnemial crest, giant tuber calcanei - nope, not really that similar to 
> bipedal dinosaurs (non-avian). Still interesting, as hopping was definitely a 
> no-go for the larger forms :)
>
>
> Dr. Heinrich Mallison
> Museum für Naturkunde - Leibniz Institute
> for Evolution and Biodiversity Science
> Invalidenstrasse 43
> 10115 Berlin
> Germany
> office: +49 (0)30 2093 8975
> cell: +49 (0)179 5429922
> email: heinrich.mallison@gmail.com, heinrich.mallison@mfn-berlin.de
> blog: dinosaurpalaeo.wordpress.com
>
> ________________________________________
> From: owner-DINOSAUR@usc.edu [owner-DINOSAUR@usc.edu] on behalf of Ben 
> Creisler [bcreisler@gmail.com]
> Sent: Wednesday, October 15, 2014 9:11 PM
> To: dinosaur@usc.edu; VRTPALEO@usc.edu
> Subject: Did giant kangaroos walk more like dinosaurs?
>
> Ben Creisler
> bcreisler@gmail.com
>
> New in PLoS ONE. The illustration looks a bit like a bipedal dinosaur
> except for the pronated forelimbs...
>
> Christine M. Janis, Karalyn Buttrill &  Borja Figueirido (2014)
> Locomotion in Extinct Giant Kangaroos: Were Sthenurines Hop-Less Monsters?
> PLoS ONE 9(10): e109888.
> doi:10.1371/journal.pone.0109888
>
> http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0109888
>
>
> Sthenurine kangaroos (Marsupialia, Diprotodontia, Macropodoidea) were
> an extinct subfamily within the family Macropodidae (kangaroos and
> rat-kangaroos). These “short-faced browsers” first appeared in the
> middle Miocene, and radiated in the Plio-Pleistocene into a diversity
> of mostly large-bodied forms, more robust than extant forms in their
> build. The largest (Procoptodon goliah) had an estimated body mass of
> 240 kg, almost three times the size of the largest living kangaroos,
> and there is speculation whether a kangaroo of this size would be
> biomechanically capable of hopping locomotion. Previously described
> aspects of sthenurine anatomy (specialized forelimbs, rigid lumbar
> spine) would limit their ability to perform the characteristic
> kangaroo pentapedal walking (using the tail as a fifth limb), an
> essential gait at slower speeds as slow hopping is energetically
> unfeasible. Analysis of limb bone measurements of sthenurines in
> comparison with extant macropodoids shows a number of anatomical
> differences, especially in the large species. The scaling of long bone
> robusticity indicates that sthenurines are following the “normal”
> allometric trend for macropodoids, while the large extant kangaroos
> are relatively gracile. Other morphological differences are indicative
> of adaptations for a novel type of locomotor behavior in sthenurines:
> they lacked many specialized features for rapid hopping, and they also
> had anatomy indicative of supporting their body with an upright trunk
> (e.g., dorsally tipped ischiae), and of supporting their weight on one
> leg at a time (e.g., larger hips and knees, stabilized ankle joint).
> We propose that sthenurines adopted a bipedal striding gait (a gait
> occasionally observed in extant tree-kangaroos): in the smaller and
> earlier forms, this gait may have been employed as an alternative to
> pentapedal locomotion at slower speeds, while in the larger
> Pleistocene forms this gait may have enabled them to evolve to body
> sizes where hopping was no longer a feasible form of more rapid
> locomotion.
>
> News story:
> http://phys.org/news/2014-10-extinct-giant-kangaroos-hop-less.html