In our 128th episode, we got a chance to talk to Thea Boodhoo, a Director at the Institute for the Study of Mongolian Dinosaurs (ISMD). You can help support the preservation of Mongolian dinosaurs and their new museum by visiting mongoliandinosaurs.org/

Episode 128 is also about Yutyrannus, a tyrannosauroid that lived in the Cretaceous in what is now northeastern China.

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In this episode, we discuss:

News:

The dinosaur of the day: Yutyrannus

Name means feathered tyrant

Tyrannosauroid that lived in the Cretaceous in what is now northeastern China

Largest known dinosaur with direct evidence of feathers

Only one species: Yutyrannus huali

Species name means “beautiful” in Mandarin and refers to the beauty of the feathers

Described in 2012 by Xu Xing and others

Three nearly complete specimens (adult, subadult, juvenile) found, all came from one quarry in Liaoning Province, China

The largest specimen is the holotype, and consists of a nearly complete skeleton with a skull

The juvenile is estimated to be 8 years younger than the adult holotype

Holotype was 30 ft (9 m) long and weighed about 3,100 lb (1,400 kg)

As Yutyrannus grew, it’s skull got deeper and more robust, and it’s lower legs, feet, ilia, and forelimbs became relatively smaller

Bipedal predator

Adult and subadult had “wavy” crests on their snouts, which were probably for display

The fact that an adult was found with a sub adult and juvenile makes some people wonder if Yutyrannus hunted in packs, but it’s hard to know for sure

Preserved feathers on Yutyrannus were about 8 in (20 cm) long and filamentous, and the feathers covered multiple parts of the body (on the pelvis and foot of the holotype, another specimen had feathers on the tail, and the juvenile had filaments on the neck and upper arm)

Possible that feathers covered the whole body

Feathers may have helped regulate body temperature, or feathers may only have been where they were found, and used for display

Yutyrannus lived in a climate that was about 50 degrees F (10 degrees C) so the feathers may have kept it warm

First known feathered tyrannosaur was Dilong, named in 2004

Yutyrannus is 40 times heavier than the previous largest known feathered dinosaur, Beipiaosaurs (a therizinosaur)

Yutyrannus is considered to be a basal tyrannosauroid, and because it had feathers, that means it’s possible that later tyrannosaurids, even as large adults, had feathers. But, late Cretaceous tyrannosaurids, like Gorgosaurus, Tarbosaurus, Tyrannosaurus, had scales on parts of the body where Yutyrannus had feathers, so it’s possible that scales evolved secondarily

Most T. rex skeletons were found in sandstone or siltstone, which are too coarse to preserve feathers, so it’s possible T. rex had feathers and the right specimen just hasn’t been found yet (Yutyrannus was found in fine sediments)

Yutyrannus had three fingers on its hand (unlike the two-fingered Tyrannosaurus and Tarbosaurus), and was missing a specially adapted middle toe that helped support its weight, which makes it a basal tyrannosauroid

Part of the family Proceratosauridae, because a 2016 study found Yutyrannus to be more basal than Dilong

Can see Yutyrannus in The Land Before Time XIV: Journey of the Brave (two of them are Sharptooth opponents)

Fun fact:

About 30 million years before the Chicxulub impact, dinosaurs went through another extinction event: the Cenomanian-Turonian extinction event

Caused by an “oceanic anoxic event” a period of low oxygen in the ocean

Possibly by changes in ocean circulation or plankton diversity

May have wiped out Spinosaurids

There were at least 2 other anoxic events in the Mesozoic 1 in Cretaceous and 1 in Jurassic



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Interview:

For those who may prefer reading, see below for the full transcript of our interview with Thea Boodhoo:

COMING SOON!