Were Heterodontosaurs Arboreal?

A newly described specimen of a tiny plant-eating dinosaur shows features indicating that it may have been able to climb around in branches -- an ability so far unknown in any dinosaurs except birds.

Dinosaurs were enormously successful vertebrates that dominated terrestrial ecosystems for almost the entire Mesozoic Era. The dinosaur family tree can be divided into three major branches: the theropods, mostly carnivorous bipeds (including birds); the sauropods, usually enormous long-necked herbivores; and the ornithischians, an incredibly diverse assemblage of beaked herbivores. Commonly known onithischians include (but are not limited to) armored dinosaurs, horned dinosaurs, bone-headed dinosaurs, and duck-bills. One of the earliest groups of ornithischians to appear in the fossil record are the heterodontosaurids, small bipeds recognizable by the long tusk-like teeth in their upper and lower beaks. Heterodontosaurids are known from the Upper Triassic to the Lower Cretaceous rocks in Africa, Asia, Europe, and North and South America and include the namesake Heterodontosaurus from the Early Jurassic of South Africa as well as the famous filament-covered Tianyulong from the Early Cretaceous of China.


In June, researchers described a new specimen of a heterodontosaurid found in Lower Jurassic rocks from Argentina dated to about 180 million years ago. The specimen, which consists of portions of the left and right foot, several toe bones, and some tail vertebrae comes from the Cañadón Asfalto Formation in near the town of Cerro Condor, Chubut Province. The authors think it’s likely that the remains belong to Manidens condorensis, a pigeon-sized heterodontosaurid found from the same location. Unfortunately the only known specimen of Manidens lacks its feet, so there are no overlapping parts that would make the assignment definitive.

link.

Pegomastax africanus: A Heterodontosaur with Bristles?

A new, tiny dinosaur with vampire-like fangs devoured ... plants?

So says a new study of Pegomastax africanus, a 2-foot-long (0.6-meter-long) heterodontosaur that lived about 200 million years ago.

[...]

Covered in porcupine-like quills and sporting a blunt, parrot-like beak, P. africanus would've looked like a "strange little bird," said Sereno, a paleontologist with the University of Chicago.

[...]

While preparing a comprehensive analysis of the little-known heterodontosaurs, Sereno identified P. africanus from fossils at Harvard University, which had been collected in South Africa in the 1960s.

To find out what the newfound dinosaur did with its sharp fangs, Sereno then reassembled P. africanus' jaw and teeth. He compared the reconstruction to jaws and teeth of both meat-eating dinosaurs and modern plant-eating mammals with fangs.

Sereno discovered that P. africanus' fangs were very similar to those of fanged deer and peccaries, which use their fangs in self-defense and competition for mates, he said.

Supporting this theory, microscopic analysis of P. africanus' fang enamel revealed wear and breakage consistent with sparring.

The researcher suggested too that the cheek teeth in P. africanus' upper and lower jaws worked like self-sharpening scissors for shearing plant parts, as detailed in the study, published online Wednesday in the journal ZooKeys.

Link to Nat Geo article.  Link to paper.

Going to read the paper.  The connection to Zookeys seems to have a craaaazy slow connection for downloading the PDF.  9.8kbps would have been great for ftp in the days of the early 90s.  That was 20 years ago.  yikes.

I'm curious where he gets the quill covering from.  The fossil?  Guessing?

Update:  I won't be able to tell for a while.  It looks like the paper is mangled.  The PDFs are damaged and the HTML version of the paper is cut off mid sentence.

The Fruitadens Paper

Lower limits of ornithischian dinosaur body size inferred from a new Upper Jurassic heterodontosaurid from North America

1. Richard J. Butler (1,2,*)
2. Peter M. Galton (3,†)
3. Laura B. Porro (4)
4. Luis M. Chiappe (5)
5. Donald M. Henderson (6)
6. Gregory M. Erickson (7)


1. Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Straße 10, 80333 Munich, Germany

2. Department of Palaeontology, The Natural History Museum, London SW7 5BD, UK

3. Professor Emeritus, College of Naturopathic Medicine, University of Bridgeport,
Bridgeport, CT 06604, USA

4. Department of Organismal Biology and Anatomy, University of Chicago, IL 60637, USA

5. The Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, CA 90007, USA

6. Royal Tyrrell Museum of Palaeontology, PO Box 7500, Drumheller, Alberta T0J 0Y0, Canada

7. Department of Biological Science, Florida State University,
Tallahassee, FL 32306-4295, USA

* Author for correspondence (butler.richard.j@gmail.com).

† Present address: 315 Southern Hills Drive, Rio Vista, CA 94571, USA.

Abstract:


The extremes of dinosaur body size have long fascinated scientists. The smallest (<1 m length) known dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65–75 cm in total body length and 0.5–0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade.

Still wish there were sabre toothed heterodontosaurid carnivores...;)

Meet Fruitadens haagarorum: North American heterodontosaurid, bitty version

The fossil bones of a dinosaur so tiny it could dart between the legs of its huge neighbors are being assembled at the Natural History Museum of Los Angeles County, and scientists there are excited about its history.

The little creature weighed less than 2 pounds and was only 28 inches long from its fierce little jaws to the end of its long tail.

Although its name is Fruitadens - fruit teeth - it probably ate all kinds of food. It likely ate plants most of the time, but bugs and other small animals, as well, said Luis Chiappe, director of the museum's Dinosaur Institute.

The first details of the dinosaur's life and evolution are being published this week in the British scientific journal Proceedings of the Royal Society B, and Chiappe is overseeing construction of a detailed, full-scale model of the animal that will take another two years to complete, he said in a phone interview Tuesday.

"It's the smallest species of dinosaur ever found in North America," Chiappe said, "and it lived about 150 million years ago - one of the most primitive of all the dinosaurs, living right at the base of the dinosaur evolutionary tree."

Bones of four individual creatures were found near Fruita, Colo., more than 30 years ago by dinosaur hunters from Cal State Long Beach. The Los Angeles County museum has stored them ever since. A team of specialists, including Chiappe and led by Richard Butler of the Bavarian State Paleontology Collection in Munich, has analyzed them and described their technical details.

"It tells you once again how dinosaurs can range in size, from 2-pound animals like Fruitadens to creatures weighing 50 tons or more like plant-eating sauropods like Brachiosaurus, or the meat-eaters like the theropod Allosaurus."

The slightly built, agile little dinosaur belongs to a class of creatures known as heterodontosaurids, whose unusually shaped teeth - some sharp and some leaf-shaped - indicate it was most probably omnivorous, Chiappe said.

WWWWWWHHHHHHHHHHOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOAAAAAAAAAAAAAAAAAA.

Itsy bitsy NORTH AMERICAN heterodontosaurids!

All of you jerks that got to go to London probably knew about this one. :P

Heterodontosaurs are my favourite after ceratopsians. :)

Ok. Question. Why no orinthschian carnivores? Theropods too good? But then why did the uber sized pterosaurs start becoming stalking ground feeders?

Just How Basal ARE Feathers for Dinosaurs?

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).

Top of page
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: