Yi qi: The Dragon of the Jurassic

The Jurassic Dragon takes flight!
Image Credit: Emily Willoughby, https://commons.m.wikimedia.org/wiki/File:Yi_qi_restoration.jpg

In a dense forest, full of hissing, rumbling and bellowing noises, a dragon perches on a branch. Using its sharp eyesight it locates its next meal; a large beetle crawling along a tree trunk 50 metres away. The dragon stretches its leathery wings and takes flight, swooping down silently with barely a flap towards its prey. However, just before the dragon can strike the beetle notices and unfurls its own wings in a desperate attempt to escape. But with a couple of quick flaps the dragon adjusts in mid-air and intercepts, snapping it out of the air with its toothy jaws. The beast lands and swallows the meal. But this is only a starter, and the little dragon surveys the forest again before moving on in search of the main course.

Believe it or not this really did occur in the Late Jurassic forests of China. But with one difference. The animal in question was not a mythological dragon, but a dinosaur named Yi qi.

The binomial name Yi qi, meaning “Strange Wing” in Chinese, is the shortest scientific name given to any dinosaur, and one of the shortest names of any animal living or extinct. It belonged to a family of theropod dinosaurs known as the Scansoriopterygidae (a real tongue twister of a name). Yi qi is one of only three known members of this group (the others being Epidexipteryx and Epidendrosaurus/Scansoriopteryx) and as a result relatively little is known about their evolutionary history and general lifestyle. The Scansoriopterygidae were part of a wider theropod order known as the paravians; which includes the dromaeosaurs (i.e. raptors) and all birds (that’s right ALL birds). However the Scansoriopterygidae seem (unless future discoveries say otherwise) to be an example of an evolutionary dead end as they are only known from sites from the Mid-Late Jurassic (and potentially Early Cretaceous) China and nowhere else.

Size comparison between Yi qi and a human being
Image Credit: Matthew Martyniuk, https://commons.m.wikimedia.org/wiki/File:Yi_scale.png

Yi qi was roughly the size of a pigeon with toothed jaws, forward facing eyes, sharp claws, long thick tail feathers and simple filament feathers covering its body, head and upper arms. The fossilised feathers are so well preserved that even the melanosomes (the small organelles that give feathers and other biological structures colour) were clearly preserved. Examination of the shape of these melanosomes, and comparison with melanosomes in living birds, showed that Yi qi had a black/grey body with reds and yellow colours on its arms. This gave it a distinctive contrasting colour scheme with the red/yellow arms perhaps used for signalling or species recognition. So far from this description Yi qi sounds more like a bird than a dragon! However when palaeontologists examined its forearms they made an astonishing discovery. An elongated third finger extended from both its hands and a long rod like bone (known as a styliform) jutted out from its wrist. These supported a skin membrane, known as a patagia, connecting the ends of its elongated fingers to the end of the styliform. It’s theorized that this membrane would also have stretched from the end of the styliform to the body, giving Yi qi “bat-like” wings (though another competing theory is that Yi qi would have had skin membranes like those of a modern gliding tree frog). These unique wings give Yi qi and its close relatives an appearance unlike any dinosaur, bird or pterosaur, one that draws comparisons with a dragon (specifically a “wyvern”). Whether Yi qi would have used these wings for powered flight or gliding (like a flying squirrel) is unclear. However it may have employed a combination of the two; long distance gliding (or as Buzz Lightyear would say “falling with style!”) and powered flapping for initial take off and manoeuvring through the air. Yi qi’s discovery also shows that flight had evolved in dinosaurs on multiple occasions, with the bat winged Yi qi being only one such evolutionary experiment.

The one and only Yi qi fossil. Note the feather covering around its body and head, as well as the styliform on its elongated wrist.
Image Credit: Kumiko, https://www.flickr.com/photos/kmkmks/27011985534/

All we know about Yi qi so far comes from one remarkable fossil that was discovered in 2007 in the Hebei province of China. It was found in the Mid-Late Jurassic age Tiaojishan formation of rocks. This is important as a large proportion of feathered dinosaurs are known from the Early Cretaceous onwards (20-30 million years after Yi qi). Therefore its discovery shows that feathers were present on dinosaurs far earlier than initially thought, with some palaeontologists suggesting that they originated even earlier than Yi qi. After its discovery the fossil was studied by a team led by the eminent Palaeontologist Xu Xang, who has described and named a whole menagerie of Chinese dinosaurs (e.g. the feathered tyrannosaur Yutyrannus). Yi qi was revealed to the world in a paper released in 2015 and it’s strange, dragon like appearance meant that it, like many dinosaur discoveries from China in the last few decades, made headlines around the world.

Yi qi is one of the most unusual dinosaur discoveries of the last decade. It proves, beyond a shadow of a doubt, that the world of palaeontology continues to unearth astounding discoveries. Discoveries that add more paint to the canvas that is the history of life on earth.

References/Further Reading

The original Xu et. al. 2015 paper describing Yi qi

Xu, X., Zheng, X., Sullivan, C. et al. A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings. Nature 521, 70–73 (2015). https://doi.org/10.1038/nature14423

A blog (originally from tetrapod zoology) published in Scientific American by palaeontologist Darren Naish on Yi qi and theories on its lifestyle and features

Naish, Darren “Yi qi Is Neat but Might Not Have Been the Black Screaming Dino-Dragon of Death”. Scientific American, May. 5, 2015, blogs.scientificamerican.com/tetrapod-zoology/yi-qi-is-neat-but-might-not-have-been-the-black-screaming-dino-dragon-of-death/

A blog written by Nick Garland and published in Earth Archives on Yi qi

Garland, Nick “Meet Yi qi, the dinosaur with bat-like wings and feathers”. Earth Archives, 2015, eartharchives.org/articles/meet-yi-qi-the-dinosaur-with-bat-like-wings-and-feathers/

Yutyrannus: The Feathered Tyrant

Image result for yutyrannus
Reconstruction of Yutyrannus huali, Feathers and all!
Image Credit: Tomopteryx, https://commons.wikimedia.org/wiki/File:Yutyrannus_huali.png

Tyrannosaurs are arguably the most famous members of the great dinosaur pantheon. Their traditional look has been set in stone in the public eye for decades, being immortalised in various media, of a giant scaly lizard with tiny arms and a massive head full of sharp, banana shaped teeth. However what if I were to tell you that this picture isn’t completely accurate, and that at least some tyrannosaurs were in fact a lot more on the soft and fluffy side! While it’s still being debated to this day whether the mighty Tyrannosaurus Rex had feathers (a story for another blog!), there was another tyrannosaur that not only possessed feathers, but was completely covered in them! Revealed to the world in 2012 Yutyrannus huali (meaning “Beautiful Feathered Tyrant” in a mix of Mandarin and Latin) shaked pre-existing ideas about Tyrannosaurs to the core.

Yutyrannus was discovered in the Yixian formation, in the Liaoning Province of China by a Chinese palaeontologist named professor Xing Xu. This particular corner of the world is extremely rich in dinosaur fossils, mostly dating to the Early Cretaceous period (125 million years ago). A large majority of the feathered dinosaur finds in the last few decades originated from this area. Xu is a big name in the world of contemporary palaeontology as described and named a lot of these feathered dinos, such as the “four winged” Microraptor and another feathered tyrannosaur called Dilong. The Yutyrannus fossils discovered by Xu and his team consisted of an adult and two juveniles, all of them almost complete. This is remarkable as tyrannosaurs are often only known from incomplete fossils. So in this case we have a vividly detailed picture of this particular animal.

One of the most surprising observations about Yutyrannus is not only that it had feathers, but that this was a big animal. Previously other known feathered tyrannosaurs, such as Dilong and Guanlong (both also discovered in China), were relatively small; ranging around the sizes as modern big cats. However Yutyrannus bucked this trend by growing up to 9 metres long, 3 metres tall and weighing up to 1 and a half tonnes. This makes Yutyrannus the largest animal with direct definitive evidence of feathers ever discovered. While other dinosaurs like Therizinosaurus and Gigantoraptor are likely to have had feathers, there’s been no direct evidence found yet, so Yutyrannus keeps the crown for now. Unlike other large tyrannosaurs Yutyrannus shares many features with other early tyrannosaurs, such as possessing three fingers instead of two and a lack of a specialised weight-bearing middle toe (used by later tyrannosaurs to support their weight). By comparing its anatomy with other tyrannosaurs it was also deduced that Yutyrannus was not a direct ancestor to T-Rex, but instead belonged to a family of tyrannosaurs that split off during the Early Cretaceous, meaning that Yutyrannus was essentially T-Rexs great great uncle. Unlike later Tyrannosaurs Yutyrannus also possessed a small, midline crest at the end of its snout. This could have been used to attract a mate or to signal other individuals, saying for example “I’m the biggest and baddest of the Yutyrannus! Keep away!”. As the fossils were of an adult and two juveniles this could potentially be a family group. It has been theorised that tyrannosaurs may have lived in groups, so perhaps this find represents the sad end of a mum or dad raising its offspring.

Size comparison between a full grown Yutyrannus and a fully grown human. As you can see this was certainly a large feathered animal!
Image Credit: Conty, https://en.m.wikipedia.org/wiki/File:Yutyrannus_SIZE.png

The feathers themselves have been found preserved in patches across the whole body of all 3 fossils. In life they were relatively simple “proto-feathers”, consisting of long simple filament like structures. These filaments would have intertwined to produce a fluffy down; somewhere between the down on a baby chicken and the longer, fibrous feathers of an emu. The primary function is likely to have been to keep Yutyrannus warm. A study by Amiot et. al. in 2011 looked at oxygen isotope compositions found in reptile fossils from East Asia. These seem to indicate that at the place and time where Yutyrannus lived was a relatively cold, compared to the hothouse that was the rest of the Mesozoic, so a feathery coat would have helped to keep an active hunter like Yutyrannus at the right temperature. Other possible usages of this coat of feathers could have been to assist with attracting mates, as has been speculated to have been the case in other feathered dinosaurs (e.g. Caudipteryx), and any shed feathers could have been used to line their nests, as it is employed by modern birds. It has even been suggested that the colour of the feathered coat would have helped Yutyrannus camouflage itself against its surroundings, a trick that is employed by most predators today. Some reconstructions have given Yutyrannus a fully white coat to blend in with a snowy background (like a polar bear). While this is a neat bit of speculation, it can’t be proven until any melanosomes that may be preserved are examined. If so then palaeontologists would be able to discover the colour of a tyrannosaur for the first time!

An illustration showing a group of Yutyrannus hunting a juvenile Dongbeititan
Image Credit: PaleoEquii, https://commons.m.wikimedia.org/wiki/File:Dongbeititan_and_Yutyrannus.jpg

A lot of criticism of these feathered dinosaurs, and particularly with ideas about feathers existing on dinosaurs that were previously thought to be scaly, is that it makes dinosaurs “less cool looking” and more like giant turkeys. However I think that Yutyrannus is an excellent example of how feathers can enhance the interest in dinosaurs, providing another side to how we see these great lizards. An animal like this would certainly make a cute pet when it’s young. However, like pet owners who buy young tiger cubs, it’ll grow up over the years into a giant unmanageable carnivore, leaving the owner thinking “I REALLY didn’t think this through!”

References/Further Reading

Xu et. al. 2012 paper describing the 3 complete skeletons of Yutyrannus, including the description of its feathers

Xu, X., Wang, K., Zhang, K. et al. A gigantic feathered dinosaur from the Lower Cretaceous of China. Nature 484, 92–95 (2012). https://doi.org/10.1038/nature10906

American Museum of Natural History blog on getting to know Yutyrannus

AMNH, “Get to Know a Dino: Yutyrannus huali”, American Museum of Natural History, Apr. 11, 2016, amnh.org/explore/news-blogs/on-exhibit-posts/get-to-know-a-dino-yutyrannus-huali

Amiot et. al. 2011 paper on oxygen isotope compositions in fossils from the Early Cretaceous East Asia

Amiot, Romain et al. “Oxygen isotopes of East Asian dinosaurs reveal exceptionally cold Early Cretaceous climates.” Proceedings of the National Academy of Sciences of the United States of America vol. 108,13 (2011): 5179-83. doi:10.1073/pnas.1011369108

A National Geographic article, written by Cliff Tarpy, about the fossils of Liaoning

Tarpy, Cliff, “Liaoning Province—China’s Extraordinary Fossil Site”, National Geographic, nationalgeographic.com/science/prehistoric-world/china-fossils/

Megalosaurus: The Original Dinosaur

An Artist reconstruction of Buckland’s great lizard
Image Credit: LadyofHats Mariana Ruiz, https://commons.m.wikimedia.org/wiki/File:Megalosaurus_dinosaur.png

There is no group of extinct life that enthrals the minds of the general public quite like dinosaurs. All palaeontologists both current and aspiring can claim to have at least been partially inspired by reading books and watching documentaries about dinosaurs, and from seeing their fossils and reconstructions in the many museums throughout the globe. Some dinosaurs have received vast amounts of media attention; the great Tyrannosaurus Rex; the three-horned Triceratops; and the long necked Brachiosaurus to name a few. However there is one dinosaur that can claim to be perhaps the most important of them all. Megalosaurus bucklandii is not as well-known as these other dinosaurs, which is quite surprising to me. However this medium-large sized theropod from the mid-Jurassic has every claim to live long in the history books.

Megalosaurus was the first dinosaur to be properly and scientifically described and the first animal to be referred to as a “dinosaur”. The first Megalosaurus fossils were discovered in the village of Stonesfield in Oxfordshire, England in the 18th century. These fossils came from a Mid-Jurassic (170-150 Million years old) deposit known as the “Stonesfield Slate”, a deposit that has also preserved the remains of other dinosaurs, pterosaurs, insects and plants of the time. The Megalosaurus fossils, originally described under the interesting name of Scrotum humanum, which was not formerly accepted by any scientific body, were passed on in 1824 to the geologist William Buckland, who in collaboration with the anatomist Georges Cuvier, identified the animal as a large extinct reptile. This animal was given the name Megalosaurus bucklandii, meaning “Buckland’s great lizard”. It was almost 20 years later in 1842 that Megalosaurus was referred to by Sir Richard Owen as a “dinosaur”. This discovery was quite unlike any living animal and captured the imagination of the Victorian public, with Megalosaurus making an appearance in the Charles Dickens novel Bleak House. This made it one of the first (but certainly not the last!) dinosaurs to appear in mainstream popular media.

A fossilised lower jaw and tooth of Megalosaurus. This jaw is one of the more iconic dinosaur fossils.
Image Credit: Wikimedia Commons, https://he.m.wikipedia.org/wiki/%D7%A7%D7%95%D7%91%D7%A5:Buckland,_Megalosaurus_jaw.jpg

Most of the Megalosaurus specimens that these early Victorian geologists had to go on were incomplete, with the only finds being a lower jaw, upper jaw, some teeth and a few thigh and leg bones. In addition this was really the first time anyone had attempted to reconstruct dinosaurs from their bones. So the Victorian scientists could only make educated guesses as to what this animal was like. While they knew, based on its tooth anatomy, that it was related to reptiles the first reconstructions of Megalosaurus were very different to what we believe today. Basing its design on modern lizards Megalosaurus was reconstructed as a massive, sluggish four legged animal, with its tail dragging along the ground and possessing a big hump on its shoulders. This interpretation can be seen in all its glory at the Crystal Palace Park in London. Unveiled in 1851 it is displayed stalking a group of equally lizard like Iguanodon, also inaccurate as Iguanodon would appear almost 40 million years after Megalosaurus (to name one inaccuracy!). It was only when further theropod remains were found a few decades later that a more accurate picture of Megalosaurus became clear. However during this time the Megalosaurus species was known as a “wastebasket taxon” where any newly discovered large theropod remains were all haphazardly lumped into the Megalosaur group, like somebody chucking different types of cutlery into the same drawer. Also the animal was portrayed, like other bipedal dinosaurs at the time, standing upright like a Kangaroo. This would only change nearly a whole century later, where research in the 1960s and 1970s led to all bipedal dinosaurs’ posture being altered to the more horizontally balanced forms seen today, where the head and body were counterbalanced by a long, lofted tail.

The Megalosaurus model at Crystal Palace park. This model, first revealed in 1851, shows us what Victorian Scientists thought it looked like.
Image Credit: Chris Sampson, https://commons.m.wikimedia.org/wiki/File:Crytsal_Palace_Megalosaurus.jpg

Whilst Megalosaurus has a long and important story about its discovery, and how it changed scientific thinking forever, what was this dinosaur actually like when it was alive? Well, Megalosaurus belonged to a group of theropods known as the Megalosauridae. This group were the main land predators of the early to mid-Jurassic period, dominating the landscape until their numbers declined during the late Jurassic 150 million years ago. Megalosaurus had many of the features that are typical of theropod dinosaurs; big hind legs, saurischian (lizard-like) hips, arms ending in non-pronated wrists, sharp claws and robust jaws filled with razor sharp teeth suitable for cutting and biting into the flesh of its prey. The powerful legs of Megalosaurus would have enabled it to reach speeds of up to 20 miles per hour, equivalent to a modern day Grizzly Bear and easily fast enough to chase down its prey. Once caught Megalosaurus would have attacked its prey with a powerful bite, its skull built for heavy impact by having a framework of slightly loose bones that, through flexing on impact were able to absorb the forces involved in biting and holding large struggling prey. Reaching up to nine metres long, three metres tall and weighing nearly one and a half tonnes it was the undisputed top predator of mid-Jurassic England, hunting large herbivorous dinosaurs, such as the long necked sauropod Cetiosaurus. However it would have needed to be an unfussy eater. During the Mid Jurassic, the UK was broken up into small islands, with Megalosaurus probably swimming from island to island and combing the beaches for any food it could find, including any marine reptiles, crabs and pterosaurs that had been beached. It is also possible, like a lot of other theropods, that Megalosaurus could have been at least partially feathered. Evidence for this comes from another megalosaurid called Sciurumimus. Found in the Late Jurassic of Germany this juvenile megalosaur was found preserved with a filamentous coating of feathers. While this isn’t direct evidence of feathers on Megalosaurus the fact that it is present on a close relative means that it is likely that it too possessed a similar coating, making it look a bit less like a scaly lizard and a bit more like a fluffy carnivorous bird. This new finding, put forward in a 2014 study by Rauhut et. al., would certainly have startled William Buckland, Richard Owen and the other Victorian scientists that first named this remarkable beast a “dinosaur”.

So, just as the 2008 film “Iron Man” was the start of the Marvel Cinematic Universe, and the Benz Patent Motor Car was the origin of today’s cars, the discovery of Megalosaurus was the genesis of dinosaur research. While T-Rex and others get the spotlight nowadays without this first description and reconstruction of this Mid-Jurassic Megalosaur from Oxford, dinosaurs would not have captured the public imagination in quite the way that they have. The field of palaeontology would perhaps have never evolved into the science it is today, and who knows, in that world I may have become an archaeologist!

References/Further Reading

Rauhut et al 2014 paper about feather filaments in the Megalosaur Sciurumimus

Rauhut, O. W. M., et al. (2012). “Exceptionally preserved juvenile megalosauroid theropod dinosaur with filamentous integument from the Late Jurassic of Germany.” Proceedings of the National Academy of Sciences 109(29): 11746-11751.

The Friends of Crystal Palace Dinosaurs page on the Megalosaurus model at Crystal Palace park, including comparisons with how the Victorian scientists thought it looked and behaved compared with modern interpretations

“Megalosaurus”, Friends of Crystal Palace Dinosaurs, cpdinosaurs.org/visit/statue-details/megalosaurus

More Information on Megalosaurus and other animals of the Stonesfield slate from the Oxford University Museum of Natural History website

“The Oxfordshire Dinosaurs”, Oxford University Museum of Natural History, oumnh.ox.ac.uk/megalosaurus-and-oxfordshire-dinosaurs