Episode 535: A Two Fingered Therizinosaur. Duonychus tsogtbaatari was found in what is now Mongolia with strong evidence that it only had two fingers on each hand. Plus the Jurassic World: Rebirth trailer, Walking with Dinosaurs is coming back, and more.

News:

• There’s a new therizinosaur with just two large claws per hand, Duonychus tsogtbaatari source
• There’s a trailer for Jurassic World: Rebirth source
• BBC’s Walking with Dinosaurs revival is coming out later this year source
• There’s a new dinosaur horror comedy, called The Invisible Raptor source
• Petition to save “Tyra” the “world’s largest dinosaur” in Drumheller source
• Petition to make T. rex the U.S. national fossil source

Sponsors:

This episode is brought to you by the Colorado Northwestern Community College. Join them for two weeks digging up dinosaur bones from the Jurassic Period in Northwest Colorado this summer. For details go to CNCC.edu/dinodig

The dinosaur of the day: Sinovenator

• Troodontid that lived in the Early Cretaceous in what is now Liaoning, China (Yixian Formation)
• Older than 128 million years
• Looked like other troodontids, walked on two legs, had a long tail, sickle claws on the feet, a long head full of sharp teeth, and raptor like hands
• Troodontids were small and bird-like, with lots of teeth and closely spaced teeth in their lower jaws. Also had sickle claws on the toes
• Two specimens (individuals) originally found
• Holotype was less than 3.3 ft (1 m) long, about the size of a chicken. Holotype is a subadult. Some specimens have been found that are twice that long
• Holotype estimated to weigh 5.5 lb (2.5 kg)
• Probably had feathers
• Fossils found in rocks deposited by a river
• No feathers found
• Had bird-like hips
• Had a triangular skull with a shallow snout
• Type and only species is Sinovenator changii
• Described in 2002 by Xu Xing, Mark Norell, and others
• Genus name means “Chinese hunter”
• Species name is in honor of Meemann Chang, who has done a lot studying the Jehol fauna
• Discovery helped further show that birds evolved from dinosaurs
• Fossils are preserved in 3D
• Found a partial skull and disarticulated skeleton
• Second individual is an incomplete but articulated skeleton
• Wrist has been found of another individual
• Another fragmentary skeleton later referred to Sinovenator later. Includes a partial skull, lower jaws, six neck bones
• A 2006 survey found there are hundreds of undescribed specimens
• One nearly complete skeleton, including the skull, found preserved in a sleeping posture, similar to Mei long
• A study of the braincase (endocast) found it was similar to Archaeopteryx
• May have had a better sense of smell compared to other troodontids (had long olfactory tract and bulbs)
• In 2015 a man from Colorado, U.S. was sentenced for trying to smuggle dinosaur fossils from China to the U.S. One of the fossils was Sinovenator, which was valued at about $70,000. All the fossils the man had were returned
• Lived in an area with wet and dry seasons, with cold winters
• Other animals that lived around the same time and place include the ceratopsian Psittacosaurus, the ornithischian Jeholosaurus, and the mammal Repenomamus

Fun Fact:

Don Bluth, who directed and co-produced The Land Before Time, started as a Disney animator before becoming a “Disney Defector”.

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