The Prehistoric Marsupial Thread

Adam Khor

In Spain, so the article is in Spanish: http://www.icp.cat/index.php/es/sala-de-prensa/noticies-icp/808-castello-marsupial

Its name is Amphiperatherium and wasn´t too different from modern day American opossums.

Rubecula

Brilliant find Adam, thank you for that.

Galvasean

Cute lil' bugger.

Adam Khor

According to this study, the giant sthenurine kangaroos such as Procoptodon or Sthenurus moved by walking bipedally, like humans or theropod dinosaurs, rather than hopping (although they may have hopped when in a hurry)

Really weird.

http://www.csmonitor.com/Science/2014/1016/Huge-prehistoric-kangaroo-was-more-the-sauntering-type-say-scientists

Rubecula

Not sure but I think there must be an upper size (weight) limit to hopping. Partly due to structural strength, and possibly due to diminishing returns. But enjoyable read Adam.

Adam Khor

http://www.dailymail.co.uk/sciencetech/article-3462010/Not-skippy-Fossils-tiny-ancient-kangaroo-couldn-t-hop-Australia.html

Adam Khor

http://www.sci-news.com/paleontology/malleodectidae-extinct-family-snail-eating-marsupials-03902.html

Adam Khor

Microleo, a diminutive marsupial lion from Miocene Australia?

The remains are really measly but if correctly interpreted, it would be a marsupial lion about the size of a squirrel

http://www.sci-news.com/paleontology/microleo-attenboroughi-new-species-marsupial-lion-04126.html

Adam Khor

Rather than holding prey with its claws and killing with its teeth, it may have done it the other way around:

http://www.sci-news.com/paleontology/marsupial-lion-thylacoleo-carnifex-hunting-style-04116.html

Capt'n Midnight

The team proposed that this unique elbow joint, in combination with the huge ‘dew claw’ on a mobile thumb, would have allowed the marsupial lion to use that claw to kill its prey.

So it's a bit like a velociraptor then ?

Adam Khor

Somewhat, although the most popular theory on Velociraptor's MO right now has it using its claws to pin prey to the ground and starting to eat it alive, no previous killing needed. Not sure If I buy it though; even If it did happen (even precisi n killers like big cats will sometimes skip the killing part, I suposse If they're really hungry), the fact that the Fighting Dinos specimen was found in the act of stabbing the Protoceratops' throat could be indicative of expert precision killing. Also, I think a study on Deinonychus found that its feet could grasp with a relative strenght comparable to a modern owl, which means they wouldn't have trouble crushing small prey and puncturing the vitals of larger ones.

Adam Khor

http://theconversation.com/a-new-species-of-marsupial-lion-tells-us-about-australias-past-88633

Close relative to the much larger and more famous Thylacoleo carnifex.

Adam Khor

http://theconversation.com/a-new-species-of-marsupial-lion-tells-us-about-australias-past-88633

Close relative to the much larger and more famous Thylacoleo carnifex.

Adam Khor

Complete Thylacoleo skeleton reveals anatomy, lifestyle.

Among the interesting parts is that its tail could support its weight in a tripodal stance, and that its back feet were rather like those of possums and allowed it to climb- but also meant it could probably not chase after prey at speed like a big cat would. Most certainly an ambush hunter and scavenger.
The study also suggests its gait would've been similar to that of the unrelated Tasmanian devil, today's largest carnivorous marsupial.

https://phys.org/news/2018-12-first-ever-skeleton-thylacoleo-australia-extinct.html

http://blogs.discovermagazine.com/deadthings/2018/12/12/thylacoleo/#.XBMiSK6Z21s

Adam Khor

Cute marsupial had ferocious fossil relative

https://phys.org/news/2019-08-cute-marsupial-fierce-fossil-relative.html

Adam Khor

Giant short-faced kangaroo Simosthenurus likened to giant panda- had very powerful bite to chew on hard food.

https://www.newsweek.com/prehistoric-giant-kangaroo-powerful-bite-1458750

These simulations indicated that the cheekbones of S. occidentalis supported large muscles that prevented dislocation of the jaw when the animal used its powerful bite.

"Interestingly, the short-faced kangaroo models were found to have a much higher risk of injury than the koala models during biting at the back teeth," Mitchell said. "This is because its teeth were much larger and extended farther back towards the jaw joints. This greatly increased how hard the animal could bite, but also increased the risk of jaw dislocation when biting."

"However, I found that an enlargement of a muscle located on the inner surface of its immense cheekbones would help to reduce this risk," he said. This muscle is also enlarged in the giant panda, another similarly sized animal that feeds on thick, resistant vegetation such as bamboo.

Furthermore, the scientist found that the bones of the front and roof of the skull provided sufficient structural support to resist the twisting forces that would have been generated during these bites.
This finding supports previous suggestions about short-faced kangaroos that the toughest, thickest vegetation that it could have eaten, such as the woody twigs and branches of trees and shrubs, may have been fed directly to its premolars and molars to be crushed or otherwise broken apart. Such actions would appear similar to how giant pandas crush bamboo," he said.

This is one of the so called sthenurine kangaroos, which include some of the largest ever to live, including the 3 m tall Procoptodon goliah, and notorious for being apparently able to walk and run bipedally, rather than moving about by hopping. Some of their limb adaptations are actually very much like those developed by our hominin ancestors for more efficient walking.

Adam Khor

Prehistoric "marsupial tapir" Palorchestes was huge, weirder than thought.

https://www.science20.com/news_staff/palorchestes_azael_wombat_ancestor_weighed_2000_lbs-241770

Adam Khor

New Australian "lion" discovered.

This tiny relative of Thylacoleo was the size of a house cat and had strong, sharp teeth able to "slice through bone".

https://www.dailymercury.com.au/news/new-australian-lion-discovered/3955500/

Adam Khor

Paper discusses several megafaunal species from Pleistocene Australia.

Most notably, a newly discovered kangaroo likely to be the largest ever found, even bigger than previous champion Procoptodon goliah, the so called giant-short faced kangaroo. Unlike the short-faced, apparently unable to hop Procoptodon, this was a macropodine and a member of genus Macropus, so it would've looked and behaved more like a typical roo.

https://www.nature.com/articles/s41467-020-15785-w

Adam Khor

New study challenges the old idea that Thylacosmilus was a sabertoothed killer. Analysis of the dentition, jaw and neck musculature, wear of the teeth and other aspects of its anatomy suggest it was poorly equipped to process meat and bone, let alone actively hunt other large animals; instead, they suggest it may have specialized on scavenging carcasses, using the powerful pulling motion of the neck (as suggested by its anatomy, which would allow for this but not for downwards stabbing as in sabercats), to open and disembowel the carcass, and a powerful tongue and palate to suck the soft innards (which could explain the lack of frontal teeth).

https://peerj.com/articles/9346/?fbclid=IwAR2bcj-NEYMoSCaSU6ZBpMvuTquGZ06dC_vZCbfszIaPajB1PY78crSd630

Adam Khor

Bear-sized wombat remains found in Australia:

http://www.sci-news.com/paleontology/mukupirna-nambensis-08578.html?fbclid=IwAR3Vn-QjloWNtdC-t0RZH2WFIIev_pLZ_XdehSULDlBZIbVMwu3039xHMg4

Adam Khor

Eomakhaira, a new sparassodontid (relative to the strange, "sabertoothed", apparently suction feeding Thylacosmilus, but with intermediate traits between it and the less derived borhyaenids.

http://digitallibrary.amnh.org/handle/2246/7235



It was apparently a rather small-sized animal.

Adam Khor

Study of the humeri of several extinct kangaroos suggests sthenurines (the "short-faced kangaroos" of Pliocene-Pleistocene Australia, some of which reached enormous size) lacked adaptations to bear weight on their forelimbs, suggesting they did not move about quadrupedally (or "pentapedally") as modern kangaroos do at lower speeds, instead walking bipedally. This fits the idea that these kangaroos did not hop, but instead walked and run- which seems to be supported by a potential sthenurine trackway.

https://link.springer.com/article/10.1007/s10914-019-09494-5



The study also finds that the "giant wallaby" Protemnodon could move about quadrupedally at all speeds. At least one Protemnodon species, P. tumbuna, had been previously suggested to have been a quadruped, hopping around much like a rabbit rather than bipedally.