Andy McGrath

See if I can rt this for #FossilFriday – at Goleta, CA

Embiid and terror birds show that even though the new athletic wings/mammals rule the day there is still room for a truly great throwback! (art by @JuliotheArtist, photoshop by me)

You know what else was a throwback? Terror birds! They were some of the top predators of #Cenozoic South America and some reached the USA during the #IceAge. Terror birds were a reminder of when theropod dinosaurs like T. rex and Allosaurus were top predators!

Starting with #NBA center @JoelEmbiid. This 7-footer is one of the current favorites for MVP and has led the #Sixers to the East's best record. Embiid dominates in the post averaging nearly 30 points and 11 rebounds per game! He's a throwback to when bigs ruled the game.

I've decided to try something new that I'm going to tentatively call #FossilAthletes. Every week(?) I'll share an athlete and say which fossil species they remind me of. Simple concept that at the very least should lead to some funny Photoshops! #scicomm

Quote this tweet with a picture of you and a fossil, and copy/paste this text. Keep it going

#FossilFriday and #DarwinDay at the same time! (I'm for sure the first to notice this). Darwin collected the holotypes of many South American #fossilmammals on his voyage including #Macrauchenia and #Megatherium (pics from Fernicola et al. 2009)

Perimys was a distant relative of modern #chinchillas that likely spent much of its time underground in burrows. Like many subterranean #rodents it had large auditory bullae (those round structures on the left of the skull) to help it hear vibrations in the earth. #FossilFriday

Glyptodonts like this #Miocene Metopotoxus were giant #armadillo relatives (right is front in these pics btw). The big bony cheek projections likely anchored lip muscles but I think they protected babies from aggressive cheek-pinching glyptodont grandmas #FossilFriday

Se llama este Paedotherium y sus familiares notoungulados (y el grupo más grande ungulados endémicos), pero unas investigaciones recientes sugieren que Paedotherium vivía como un roedor y evolucionó convergente músculos para masticar como ardillas. (foto de @AMNH)

While we call things like this Paedotherium notoungulates (or more generally South American native UNGULATES), recent research suggests that it lived more like rodents and convergently evolved chewing muscles similar to squirrels! (photo mine from @AMNH) #FossilFriday

No doubt these paintings are an amazing discovery and shed light on some animals that we have very little idea of how they lived or even what they looked like! Next up is a Macrauchenia frozen in a glacier! (trunkless by @VelizarSim & trunked by @MAntonPaleoart)

My ultimate conclusion is that macraucheniids did NOT have smooth snouts. Their nose/upper lip area was enlarged for some purpose, but I have a hard time believing it was a tapir-like muscular trunk useful for grabbing vegetation. (Promacrauchenia from @MacnVp)

But this thing painted on a wall in Colombia has a trunk right? Well I'd need to see a better photo of it first. This image seems like it was taken at a bit of an oblique angle but there's clearly something weird going on with this animal's snout.

Moyano and Giannini (2018) systematically ID'd features of various trunked and prehensile-lipped mammals. They actually found macraucheniids to be most similar to moose in the characters they ID'd! Maybe macraucheniids had moose-like prehensile lips? doi.org/10.1016/j.jcz.2018.0…

Compare this to the most famous living short-trunked mammal the tapir. The nasal bones are small, but present, and serve as anchors for soft tissues associated with moving their trunks.

Is this trunk actually supported by the evidence though? I'm less convinced. If we take a look at the top of the Macrauchenia skull again, it's very smooth.

This weird nasal opening has been used as justification for giving Macrauchenia and its close relatives a small tapir-like trunk for decades. The most famous depiction of this is probably from BBC's Walking with (Prehistoric) Beasts.

Fun fact: when I first saw this cast in @dcpaleo's office as a freshman I thought it was an early whale with a blowhole on top. Little did I know I was on my way to being a macraucheniologist™️

As you can see in this Macrauchenia, they had giant holes in their heads. This is the internal nasal opening. Over millions of years, macraucheniids' nasal bones shrunk and opening moved back until the nasals disappeared completely and the nasal opening was on top of the head.