In our 75th episode of I Know Dino, we had the pleasure of speaking with Dr. Manabu Sakamoto, a paleontologist from the University of Reading in the UK and the lead researcher of the paper, “Dinosaurs in decline tens of millions of years before their final extinction,” which was published in the Proceedings of the National Academy of Sciences in April 2016. He is an expert in phylogenetic analysis and evolution, among other things. And you can reach him via Twitter @drmambobob.
Episode 75 is also about Sinraptor, an allosauroid theropod that lived in the Jurassic in what is now China.
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In this episode, we discuss:
- The dinosaur of the day: Sinraptor
- Name mean’s “Chinese thief”
- Two species: Sinraptor dongi and Sinraptor hepingensis
- Philip J. Currie and Xian Zhao described Sinraptor in 1994
- Currie and Zhao named dongi in their 1994 paper “A new carnosaur (Dinosauria, Theropoda) from the Jurassic of Xinjiang, People’s Republic of China” published in the Canadian Journal of Earth Sciences
- Holotype found in the Shishugou Formation during a joint Chinese and Canadian expedition, called the Dinosaur Project, in 1987
- Formation means “Stone tree ravine”
- Sinraptor dongi skeleton was mostly complete, minus a lot of the tail and arms
- Sinraptor dongi holotype was found lying on its right side. Had a skull almost 36 in (90 cm) long,
- Species name is in honor of Dong Zhiming, a paleontologist (Dong Zhiming worked to describe Yangchuanosaurus)
- Sinraptor hepingensis was originally named Yangchuanosaurus hepingensis in 1992 (Yangchuanosaurus and Sinraptor are closely related); renamed in Currie and Zhao’s paper because they found new material that more closely resembled Sinraptor than the holotype for Yangchuanosaurus
- New material found for Sinraptor hepingensis includes a skull, axial skeleton, pectoral and pelvic girdles, and left femur
- Not actually a raptor (dromaeosaurid)
- Not the first time a non-dromaeosaurid has raptor in its name (ex: Fukuiraptor)
- Theropod that lived in the late Jurassic
- Allosauroid theropod that is more primitive than allosaurids such as Allosaurus and Acrocanthosaurus
- Premaxilla had 4 teeth, which is considered more primitive
- Closest relative is another theropod found in China, Yangchuanosaurus, but Sinraptor had a longer, lower skull
- About 10 ft (3 m) tall and 23.5 ft (7.2 m) long (but not fully grown)
- Probably a top predator (not the largest in its habitat)
- Probably hunted smaller dinosaurs and juvenile sauropods
- Other animals that lived around the same time were turtles, lizards, sauropods related to Mamenchisaurus, hypsilophodonts, and mammals
- Had a mild climate, with seasons
- Sinraptor dongi specimen had 25 partially healed bite wounds, probably from Sinraptor fighting with other Sinraptors over food or territory (head wounds)
- The skeleton of Sinraptor dongi had a broken rib and puncture wounds in its skull
- Can see Sinraptor hepingensis at the Zigong Dinosaur Museum in Zigong, China
- Part of Carnosauria, a group of allosaurs and close relatives that lived in the Jurassic and Cretaceous
- Includes Giganotosaurus and Tyrannotitan
- Had large eyes, a long narrow skull and thighs that were longer than their shins
- Also part of Metriacanthosauridae (large predators, some as large as 33 ft (10 m)
- And part of the clade Sinraptoridae
- Sinraptorids are large theropods that lived in the Jurassic in Asia (similar to allosaurids and more derived than megalosaurids)
- Includes Sinraptor and Yangchuanosaurus
- Fun fact: From the article titled “Triggering of the largest Deccan eruptions by the Chicxulub impact” by Mark A Richards and others, from studying the Deccan “traps” it’s estimated that at least 500,000km3 (120,000mi3) of lava flows occurred over about a 100,000 year period.
For those who may prefer reading, see below for the full transcript of our interview with Dr. Manabu Sakamoto:Continue Reading …