Thread by @chumblebiome

NEXT UP: 3rd seeded Dimetrodon limbatus vs 2nd seeded Amebelodon fricki!!! #2018MMM

Hand-claps for @MarcKissel who wrote this amazing BATTLE OF THE DONS!!! #2018MMM (I'm just the messenger tonight)

Dimetrodon has already defeated Aegyptopithecus zeuxis & devoured Pseudaelurus quadridentatus, while Amebelodon has out-competed Deinogalerix koenigswald & scared off Homo floresiensis #2018MMM

Dimetrodon was an apex predator. Their powerful teeth & jaws made them a fearful predator. The distinctive dorsal sail is made up of the elongated part of the spinous process of the back bone (you can feel your own spinous process along the back of your spine) #2018MMM

The tips of the bone of Dimetrodon's sail curve irregularly "like the fingernails of the senescent Howard Hughes" Rega et al. 2012 (bioone.org/doi/full/10.31…) #BestAnalogyEver #2018MMM

Remember, if you learn nothing else about the lovely Dimetrodon, know that it was <not> a dinosaur. While they are not-quite-mammals, you are more closely related to Dimetrodon than Dimetrodon was to a T. Rex! #2018MMM

As we've mentioned before, Amebelodon (named in 1927) is known to be a distant relative of the modern elephant. This order of elephant-like creatures, Proboscidea, originated in Africa pnas.org/content/21/6/4… #2018MMM

Proboscidea migrated out of Africa & "through all the continents and climates of the globe except Australia" potentially because of overpopulation. In each new climate, they adapted in new ways, which resulted in much diversity & specialization jstor.org/stable/pdf/137… #2018MMM

Amebelodon's ancestors were the shovel-tuskers Phiomia osborni of the Middle Oligocene of Egypt, which were the most ancient & one of the most highly specialized of 3 distinct phyla of mastodonts which frequented shallow lake borders (Osborn 1934) #2018MMM

Our battle takes place in the Ash Hollow Formation of Nebraska (goo.gl/tKQvuY), where many Amebelodon fricki bones have been found. Some specimens had lower jaws (AKA, mandibles) & tusks (AKA incisors) that were ~2m long (Osborn 1936)! archive.org/details/probos… #2018MMM

It is unknown how big Amebelodon fricki were, but the bodies of some members of the genus were as big as 3 m long & 3 m tall #2018MMM

Amebelodon occupied a mosaic, but mostly dry, environment & used its tusks to scrape bark. Its trunk was probably much like an modern elephant wired.com/2011/04/anothe… #2018MMM

Dimetrodon is looking for its own food. Recent work suggests that they fed in shallow waters hunting sharks (Dimetrodon teeth have been found embedded in shark fossils! livescience.com/48387-permian-…) #2018MMM

Dimetrodon, having wandered into the Amebelodon's environment is not really sure what to do. But he spots a baby Amebelodon which looks like an easy meal & potential #carnage #2018MMM

Dimetrodon tries to bite the the not-quite-elephant. Its serreated teeth were adapted to tearing flesh nature.com/ncomms/2014/14… @kirstisaur #2018MMM

Amebelodon, noticing what the definitely-not-a-dinosaur Dimetrodon is up to, rushes toward it to protect the baby #2018MMM

Modern elephants will protect babies from predators #2018MMM