An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures
Xiao-Ting Zheng1, Hai-Lu You2, Xing Xu3 & Zhi-Ming Dong3
1. Shandong Tianyu Museum of Nature, Lianhuashan Road West, Pingyi, Shandong, 273300, China
2. Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, China
3. Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xiwai Street, Beijing 100044, China
Correspondence to: Hai-Lu You2 Correspondence and requests for materials should be addressed to H.-L.Y. (Email: youhailu@gmail.com).
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Abstract
Ornithischia is one of the two major groups of dinosaurs, with heterodontosauridae as one of its major clades. Heterodontosauridae is characterized by small, gracile bodies and a problematic phylogenetic position1, 2. Recent phylogenetic work indicates that it represents the most basal group of all well-known ornithischians3. Previous heterodontosaurid records are mainly from the Early Jurassic period (205–190 million years ago) of Africa1, 3. Here we report a new heterodontosaurid, Tianyulong confuciusi gen. et sp. nov., from the Early Cretaceous period (144–99 million years ago) of western Liaoning Province, China. Tianyulong extends the geographical distribution of heterodontosaurids to Asia and confirms the clade's previously questionable temporal range extension into the Early Cretaceous period. More surprisingly, Tianyulong bears long, singular and unbranched filamentous integumentary (outer skin) structures. This represents the first confirmed report, to our knowledge, of filamentous integumentary structures in an ornithischian dinosaur.
1. Shandong Tianyu Museum of Nature, Lianhuashan Road West, Pingyi, Shandong, 273300, China
2. Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, China
3. Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xiwai Street, Beijing 100044, China
Link at the top is to the paper. First seen at Chinleana, but also at Not Exactly Rocket Science and on Yahoo News.
Since I first came across them, I have found the heterodontosaurs to be absolutely fascinating. The fact that they are now in Laurasia and made it to the Cretaceous, is just plain kewl. After all, here's a dinosaur that had freakin canines! (well, sorta canines) After ceratopsians, they're my favorites.
Why is the dating so loosely constrained?
For the phylogeny geeks:
2 comments:
I just collapsed to my knees, then my jaw fell open and hit the floor. Ouuuuch! But it's a GOOD kind of pain, you know?
I don't think the implications here can be overstated. Feathers on a basal ornithischian are HUGE, potentially more important than Archaeopteryx. As soon as somebody sends me the paper, I will be writing a ginormous blog about this.
It still hasn't sunk in yet. It's just...so...mind-blowing.
The cladogram doesn't appear to be the most accurate. For example, it lists "hypsilophodonts" as basal to the clade of ornithopods+marginocephalia, even though fossils have shown that marginocephalians either form their own unique clade with heterodontosaurids (Heterodontosauriformes) or are a sister group to the ornithopoda. Othniela (or Othnielosaurus to some) is defintiely an ornithopod. And of course, as mentioned above there is the fact that some studies (like that of Yinlong) suggest that marginocephalians and heterodontosaurids are related.
But I can let that go (though not the ornithopod mixup) simply because this discovery is so huge. Its the biggest discovery in paleontology since Sinosauropteryx came out of Liaoning. Its awesome, plain and simple.
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