Thread by @albertonykus

Seeing lots of love for Mononykus in #PrehistoricPlanet, including from producers @Jon_Favreau and @MikeGunton. Mononykus was part of a group called the alvarezsaurs, and as someone who has adopted one as my username for years, I was very impressed by its portrayal! Here's why...

Alvarezsaurs were a group of small theropod dinosaurs, mostly pigeon- to turkey-sized. They were pretty closely related to birds (but not as close as, say, Velociraptor) and one species has been preserved with remains of a feathery coat. #PrehistoricPlanet (📷@skeletaldrawing)

One of the strangest features of Late Cretaceous alvarezsaurs were their forelimbs: extremely short and stout, with stiffened joints to avoid dislocation, HUGE attachments for muscles that pull towards the body, and a single enlarged claw. #PrehistoricPlanet (📷Perle et al.)

We only see this set of traits in animals that hunt for social insects by using their forelimbs to tear open hard substrates: anteaters (pictured), pangolins, and some armadillos. So this is also our best guess for how alvarezsaurs fed. #PrehistoricPlanet (📷@PTPritchard et al.)

In #PrehistoricPlanet, Mononykus digs up termites from dead wood, not a termite mound. Traces of wood-nesting termites are common in some Cretaceous deposits, whereas it is disputed whether mound-building termites were present in the Mesozoic at all. (📷Joe Kunkel)

Termite-eaters also often have a long tongue. A tongue skeleton (“hyo” in picture) is preserved in one alvarezsaur specimen and reported to be “well-developed”. A toothless tip of the lower jaw may have allowed a long tongue to protrude. #PrehistoricPlanet (📷@ChiappeLuis et al.)

Alvarezsaurs had very long legs for their size, which probably helped them not only escape predators, but also travel efficiently for long distances. And as mentioned on #PrehistoricPlanet, alvarezsaurs may have traveled a lot, for insect colonies can be very widely dispersed.

The newest alvarezsaur discovery shown in #PrehistoricPlanet is their great hearing! A study last year found they had similar inner ear structure to barn owls, which hunt by ear. Some modern termite-eaters like the bat-eared fox listen for prey, too. (📷@jonahchoiniere et al.)

For more about the biology of Mononykus and its close relatives, I wrote a popular article a couple years ago covering most of these topics in more detail: albertonykus.blogspot.com/2020/05/making… #PrehistoricPlanet (📷@DinosaurDrawing)

Alvarezsaurs were previously featured on Chased by Dinosaurs (2002) and Dinosaur Planet (2003), but neither truly highlighted how amazing they were. I couldn’t be more pleased with their depiction in #PrehistoricPlanet, and the fact so many viewers are now enamored by them!