Visiting the New Jersey State Museum: Dryptosaurus gets a Mount (FINALLY)

Scroll up.  See the dinosaurs I painted for this site's banner up there?  They are Dryptosaurus and Hadrosaurus, the first two dinosaur skeletons ever recognized by modern science in the United States.  Just as important to me is the fact that they were both unearthed in New Jersey, my home state.  That being said they are both dear to my heart.  In fact, Dryptosaurus I would go so far to say is my all time favorite carnivorous dinosaur.  Sadly, despite their historical and scientific importance, both of these dinosaurs are grossly underrepresented in many aspects of paleontology culture, especially Dryptosaurus for reasons that are still a mystery to me.  Seriously, any appearance this dinosaur ever makes is a rare treat. Toy companies that make dinosaur figures especially frustrate me.  Are you reading this, Safari?  How about you, CollectA?  Seriously, give Dryptosaurus (and Hadrosaurus too while we're at it) a freaking figure already!  You can only redo Tyrannosaurus so many times!

Basically me if a Dryptosaurus toy is ever actually mass produced.

Perhaps even sadder was the fact that despite being such an important fossil discovery, Dryptosaurus never actually got a skeleton of it erected anywhere.  If anything you would only ever see its bones laid out on a flat surface someplace.  And yes, I hear some of you smug, self-proclaimed experts back there. "Dryptosaurus is too fragmentary to get a skeletal mount!" Nope.  Sorry that won't work with me.  Dinosaurs from WAY more scant remains have gotten full skeletal mounts before.

Argentinosaurus huinculensis reconstruction at Museo Municipal Carmen Funes, Plaza Huincul, Neuquén, Argentina.

It seemed that Dryptosaurus would never get a skeletal mount for people to really see and appreciate the true majesty of this amazing beast...until now!  The New Jersey State Museum in Trenton, NJ, is the first facility in history to have not just one, but TWO Dryptosaurus skeletal mounts on display in their new, as of July 2016, natural history hall!  I was able to make a trip over there recently to check them out in person.  They are nothing short of spectacular.

OMG THEY'RE SO COOL!

Now that we have seen them and are done scooping the mush back into our open skulls from having our minds utterly blown from sheer awesomeness, lets check these guys out a little more closely.  The first thing you will notice is the especially dynamic pose.  That wasn't chosen for this exhibit purely based on the fact that it looks cool.  There is history there.  Dryptosaurus was one of the dinosaurs painted by famed illustrator Charles Knight back in 1896. (Charles Knight is widely accepted as pretty much the most influential paleoartist of all time.) He depicted two Dryptosaurus fighting in this exact pose and named it "Leaping Laelaps". (Laelaps was the original name of Dryptosaurus)  This was a big deal back then since every other illustration of a dinosaur ever portrayed during that time and even for decades after were as sluggish tail-dragging cold-blooded lizard creatures.  This was extremely progressive and even seen as downright unlikely at that time.  The painting, itself, looks like it was done in the 1990s if one didn't know the context.

Charles Knight's "Leaping Laelaps" painting.  They may not look special by today's standards but at the time this sort of depiction was unheard of and still didn't catch on until almost one hundred years later.

Remember when I mentioned that Dryptosaurus was only known from fragmentary remains?  This means that the folks at the NJ State Museum had to be especially thoughtful when reconstructing the rest of the skeletons since some of the bones had to be made based on guesswork.  This is especially tricky when the skeleton in question is missing a head.  In the case of Dryptosaurus we have some of the skull including part of the jaws and some other bits...but not enough to get a definite picture.  I got into contact with some people I know from the museum, including volunteer, Wayne Callahan, assistant curator, Jason Schein, and Curator David Parris, to get some more details on these skeletons.  What I found out was that elements from a few other related, but more completely known, kinds of dinosaurs were used as references to fill in missing gaps.  Most notably was Appalachiosaurus.  Appalachiosaurus was another kind of tyrannosauroid that lived on the east coast of North America, and was probably the closest relative to Dryptosaurus that we know of.  Elements from the much older, basal tyrannosauroid, Dilong, and the two-fingered tyrannosaurid, Gorgosaurus, are also used.

The last thing you'd see...

In addition to the Dryptosaurus skeletons, the New Jersey State museum has plenty of other awesome additions to its natural history hall.  There is now a fossil lab right there in the public viewing area where you can see volunteers and scientists prepping real fossils behind glass.  It was there that I met Hank, another volunteer, as he was using an air scribe to chip the excess rock off of a prehistoric crocodile skull that was discovered in southern New Jersey.

Tip of the crocodile's snout

Closeup of one of the crocodile's teeth with Hank's hand for scale.

Finally I saw an old familiar face...er...skull in the form of the New Jersey Elk Moose!  If you have been following me since 2012 you might remember this fellow from a guest article my friend, Amanda, provided when she was studying prehistoric deer.  This very specimen was the one she had to get teeth measurements from.

The NJ Elk Moose on display in the new Natural History Hall at the NJ State Museum.

There is much more to explore at the New Jersey State Museum.  If you get the chance definitely stop by and pay it a visit.  The Dryptosaurus skeletons alone are worth it!

Cladoselache: Prehistoric Beast of the Week

Get your diving gear ready...and time machines too I guess.  We are about to check out another awesome prehistoric shark!  Say hello to Cladoselache!  Cladoselache was a genus of shark that included several species, but the most well understood is called Cladoselache fyleri.  It lived during the late Devonian period, about 375 million years ago.  (much older than the first dinosaurs) It swam in oceans that once covered what is now North America, the best preserved specimens of this ancient fish being from Ohio.  Cladoselache could grow to be about six feet long from snout to tail and would have eaten meat (like all sharks) in life.  The genus name translates to "Branch Tooth Shark" due to the fact that could have multiple teeth per root.

Life reconstruction of Cladoselache fyleri, by Christopher DiPiazza

Cladoselache was a very interesting animal due to the fact that, despite being so old, it had some characteristics about it that are still very prominent in sharks today.  At the same time it also had some features that are completely alien by living shark standards.  The mouth of this shark was at the very front of the snout, called a terminal mouth.  This is in contrast to the kinds of mouths that you see in many modern sharks, like great whites for instance, that have that long nose jutting out before their actual mouths. (which is called subterminal)  However, some sharks today also exhibit the terminal mouth, like the weirdly wonderful Frilled Shark, for instance.  Inside the mouth Cladoselache had many long pointed teeth, that could branch out from a single root.  The teeth weren't serrated, suggesting it didn't tear apart its prey, but rather would have hooked it and sucked it completely into its jaws whole.  In fact, some very well-preserved specimens of Cladoselache even show whole fish skeletons in the stomach cavity.  Thanks to these we even can tell that Cladoselache grabbed and swallowed its prey tail-first!  Cladoselache fyleri also had seven gill slits on each side of its head, which is more than most sharks today, but also not unheard of by modern shark standards either.

Cladoselache tooth.  Note the multiple points.

One feature about Cladoselache that you won't find in any modern sharks is the fact that it was almost devoid of any toothy scales, called denticles, that sharks are so well known for being covered in.  In fact, this shark was almost completely naked, scale-wise, except for a few regions around the face and on its fins.  Paleontologists still have no clue why this was.  It also had short spines in front of its two dorsal (back) fins which may have helped it cut the water as it swam.

Cladoselache fyleri fossil on display at the American Museum of Natural History in New York.

Thanks to beautifully preserves specimens of Cladoselache, we even know what the outline of its body looked like.  This is rare since shark skeletons are almost completely composed of soft cartilage, not bone, and therefore rarely fossilize.  Most other kinds of prehistoric sharks are only known from teeth.  Not the case with Cladoselache, though.  It had a long, streamlined body and its tail was an almost perfectly symmetrical crescent shape with pronounced keels on the sides for tail muscles.  When you compare this to the tails of sharks and other fish today, you will see that symmetrical shape is present in extremely fast-swimming creatures like Mako Sharks and Tuna.  It is likely Cladoselache was fast, too, using its speed to grab prey and also escape predators, like the twenty-foot long, armored fish, Dunkleosteus.

That is all for this week!  As always please comment below on the facebook page!

References

"Ancient Sharks." Ancient Sharks. Reequest Center for Shark Research N.p., n.d. Web. 04 July 2016. 

A. S. Woodward & E. J. White, The dermal tubercles of the Upper Devonian shark Cladosclache. - Annals and Magazine of Natural History 11: 367–368. - 1938.

B. Dean, Contributions to the morphology of Cladoselache (Cladodus). Journal of Morphology 9:87–114. - 1894.

Paraceratherium: Beast of the Week

This week let's take a look at the largest land mammal of all time. (That we know of.)  Make way for Paraceratherium transouralicum!  Paraceratherium was a plant-eating mammal that lived all over what is now Eurasia during the late Paleogene Period, between 34 and 23 million years ago.  It was gigantic, towering over all other land mammals, including elephants, at up to sixteen feet tall at the shoulder (not including the long neck and head), and almost twenty five feet long. (Keep in mind this animal did NOT have a long tail.  A 25-foot long dinosaur isn't as large because of the long tail in the back takes up a lot of that length.)

Paraceratherium life reconstruction by Christopher DiPiazza

Paraceratherium has changed its name since its discovery a few times.  This is because specimens of it have all been pretty fragmentary, and therefore given names when initially discovered until it was realized they were all from the same kind of beast.  It may be more recognizable by the name, Indricotherium, which has since been lumped with Paraceratherium.  This was what it was called when it was featured on the BBC miniseries, Walking with Prehistoric Beasts. (Sequel to Walking with Dinosaurs)  Within the genus, Paraceratherium, there have been a few species named, but P. transauralicum is the most well-studied.

Paraceratherium skull on display at the American Museum of Natural History in New York

So what kind of mammal was Paraceratherium exactly?  It doesn't quite resemble any of the other large land mammals we know today.  The answer can be found when you look at its skeleton more closely.  Even though all specimens of it are mostly fragmentary, we do have good skull material.  If you look at the teeth of this animal, you will see large molars for grinding in the back, and pointed incisors in the front on both the upper and lower jaws.  This gives it away as  belonging to the order, perrisodactyla, which includes modern horses, tapirs, and rhinos.  So think of Paraceratherium as a really huge, hornless rhino.  The shape of the nasal cavity also tells us, by comparing it to skulls of its living relatives, that it likely had flexible, strong lips, or perhaps even a short trunk, like tapirs do.  Reconstructions of this animal's face seem to vary since horses, rhinos, and tapirs all have varying versions of a similar adaptation in this area.

It is likely, judging by the wear found on its teeth, that Paraceratherium was a browser, eating leaves from the tops of trees in life.  Since leaves have very little actual nutritional value as a food, animals, like Paraceratherium, need to eat large quantities in order to sustain themselves.  They also have large guts for fermenting tough-to-digest plant material, and and long digestive tracts to get as much nutrition out of the food as possible before its finally pooped out.  Because of this leafy diet (as oppose to grass which can just be sucked up with a wide mouth)

Perrisodactylids are known for their flexible lips. However, among them there is a wide variety of lips. Rhinos can have wide, or pointed lips.  Horses have rounded lips, and tapirs have short trunks.  This is all dependent on their feeding style.  My reconstruction of Paraceratherium has something between a White Rhino's wide lip and a tapir's short trunk.  This would allow Paraceratherium to select as many edible leaves as possible with less effort, something very important for large animals that rely on low-nutrition foods like leaves.  (It may have had something different. That's just my hypothesis.)

It was recently suggested that because of it's immense size, Paraceratherium would have needed an efficient way to have regulated its body temperature, especially when it came to cooling off.  Some scientists have suggested that Paraceratherium had large ears, like an elephant, where blood could be closer to the cooler outside temperatures before flowing back into the rest of the body, ultimately preventing the animal from overheating.  Many mammals from desert environments today have large ears for this reason.

The Fennec Fox, which lives in the Sahara, has extremely large ears for heat dissipation.  Larger animals like elephants use this same adaptation, and Paraceratherium may have as well.

 That is all for this week!   As always feel free to comment below or on our facebook page!

References

 Antoine, P. O.; Karadenizli, L.; Saraç, G. E.; Sen, S. (2008). "A giant rhinocerotoid (Mammalia, Perissodactyla) from the Late Oligocene of north-central Anatolia (Turkey)". Zoological Journal of the Linnean Society 152 (3): 581–592. 

Martin, C.; Bentaleb, I.; Antoine, P. -O. (2011). "Pakistan mammal tooth stable isotopes show paleoclimatic and paleoenvironmental changes since the early Oligocene". Palaeogeography, Palaeoclimatology, Palaeoecology 311: 19–29.

Prothero, 2013. Rhinoceros Giants: "The Paleobiology of Indrichotheres". pp. 87–106

Wang, Y.; Deng, T. (2005). "A 25 m.y. Isotopic record of paleodiet and environmental change from fossil mammals and paleosols from the NE margin of the Tibetan Plateau". Earth and Planetary Science Letters 236: 322–338.

Aquilonifer: Beast of the Week

This week we will be looking at a tiny creature that gives us insight to how some of the earliest mothers raised their young.  Check out Aquilonifer spinosus!  Aquilonifer was a small arthropod (same group of animals that includes insects, arachnids, and crustaceans) that lived in what is now Hertfordshire, England, during the Silurian Period, about 430 million years ago.  It measured only about a centimeter long as an adult and would have scuttled around on the ocean floor. We are unsure as to what it ate but it may have been a scavenger, sifting through the sand, and eating any tiny morsel of organic material it could find.  Judging by its mouthparts it may also have been a predator, subduing and eating smaller animals it came across.  The genus name, Aquilonifer, translates to "Kite Carrier" and the species, name spinosus, translates to "spiny".  It was also referred to as "The Kite Runner" by paleontologists who found and studied it for the fashion in which it cared for its young.

Life reconstruction by Christopher DiPiazza

This little creature was found with ten even tinier arthropod organisms attached to its body via fine threads.  At first it was hypothesized they may have been some sort of parasite, but that doesn't make much sense since all known parasites would need to be much closer to their hosts in order to survive, not floating behind it on a string.  It was then determined, upon looking at them more closely, that they were most likely offspring.  This creature would have dragged its kids around like little parasailers underwater!  Even though no animal known today does anything quite like this, many arthropods do carry their young around with them via other means.  Many spiders carry their eggs and young in a silk pouch attached to the abdomen, and mother scorpions pile their liveborn offspring onto their backs.  Considering how old and distantly related Aquilonifer is to these modern creatures, to say this was indeed a method of parenting isn't really unreasonable.  Parasites, on the other hand, tend to be pretty consistent across the board in wanting to be on or inside their hosts.

Basically this, but with less character-building experience.

Aquilonifer was also interesting in that beyond being an arthropod...scientists can't quite figure out exactly where it belongs on the family tree.  It may have been an extremely early branch of the arthropod phylum, that would eventually radiate into the forms that you see today.  When alive it may have crawled around on the ocean floor similar to a centipede does on land with its 26 legs.  It had a long pair of feelers in the front, what appear to be mandibles in the front, and ...get this....no eyes.  This isn't that crazy if you think about it.  This creature probably relied mostly on feeling in an environment where having a sense of sight wouldn't have benefited it.

High power 3D scanning of the tiny fossil allowed scientists to get a more detailed view of its anatomy.

That's it for this week!  As always feel free to comment below or on our facebook page!

References

Siveter, David J, Siveter, Derek J, Sutton, MD and Legg, D, 2016, Tiny individuals attached to a new Silurian arthropod suggest a unique mode of brood care, PNAS Online 

 Jonathan Webb, BBC News, 4 April 2016, Bizarre fossil hauled its offspring around 'like kites'

Confuciusornis: Beast of the Week

This week we will be checking out possibly one of the most well-understood of all the prehistoric dinosaurs.  Check out Conficiusornis sanctus!  Confuciusornis was a prehistoric bird, that lived in what is now China, during the early Cretaceous Period, between 125 and 121 million years ago.  From beak to tail it measured about a foot and a half long, and had a wingspan of a bit over two feet wide.  When alive, Confuciusornis would have eaten meat but also probably ate plant material, possibly seeds, as well.  Its name translates to "Confucius Bird Sage", in reference to Confucius, the famous Chinese philosopher.

Confuciusornis is known from literally thousands of fossilized specimens, which is unheard of when it comes to other dinosaur fossils.  Because of this we know quite a bit about its anatomy and lifestyle.

Confucius fossil pair.  Possibly a male and female. (note the long tail feathers)

First of all, many of the Confuciusornis specimens preserved soft tissue, including feathers.  It had long, narrow primary feathers on the wings and certain individuals had a pair of extremely long, ribbon like feathers growing from their tails.  It has been suggested that Confuciusornis was sexually dimorphic, the males possessing the long ribbon feathers for display.  It is also possible that both sexes had these feathers, and certain individuals were molting (shedding old feathers) at the time of their deaths.  The presence of these feathers also didn't have any correlation with body size, so if it was sex-related, the males and females were the same size as adults.  These tail feathers are interesting in that only the tips demonstrate the classic feather structure with a central shaft, branching off into barbs on either side.

Confuciusornis possessed a large, toothless beak, like modern birds.  However, there were other prehistoric birds that lived after Confusiusornis had gone extinct that still had teeth.  This proves that Confuciusornis evolved its beak independently of those that we see in modern birds.  The beak would have been relatively powerful in life, and many scientists suggest it could have been a seed-eater.  Modern seed-eating birds, like cardinals and sparrows, have similarly shaped beaks.  However, some doubt this since no gastroliths, small rocks swallowed by animals to help digest hard food, like seeds, were ever found in any Confuciusornis specimen. (and we HAVE found them in many other dinosaur fossils) We know Confuciusornis  at least ate small fish, since the remains of one was found in the neck region of one specimen.  This could have been the crop, a pouch in the throat region of birds, used for storing food before swallowing.

The wings of Confuciusornis tell us that this dinosaur probably could fly, but it wouldn't have been as agile in the air as many modern birds are, especially for long periods of time.  We hypothesize this because Confuciusornis doesn't have a very large breastbone, or keel as it's called in birds, for wing muscles to attach.  Keel bones in many modern birds are proportionally huge.  Even the ones on domestic chickens and turkeys are large. (Next time you eat a rotisserie chicken check this out.  It's where the breast meat attaches to the skeleton.)  Confuciusornis also didn't have as wide of a range of motion in its shoulder joints as modern flying birds do, which would have made flapping a bit more difficult for it.  Finally, it's tail lacked the broad steering feathers found in modern birds.  The hands of Confuciusornis had three distinct fingers, tipped with curved claws, which is something else not common in modern birds.

Confuciusornis life reconstruction showing some display behavior by Christopher DiPiazza.

Lastly, scientists may have figured out what color Conficiusornis' feathers were!  Since the fossilized feathers were so well preserved, scientists were able to look at them under a powerful microscope and see the shapes of melanosomes, organelles that give color to a feather.  Even though the color, itself, wasn't visible, the shape of the organelle would reflect the pigment that would have been there in life.  By comparing these shapes to those of modern bird feather melanosomes, they were able to conclude that Confuciusornis likely had a dark gray body, black tail feathers, and possibly white primary feathers.  However, it should be noted that not ALL kinds of melanosomes necessarily preserved, so an overlapping of different kinds of these organelles may have yielded a different coloration in certain areas.

That is all for this week!  As always feel free to comment below or on our facebook page!

References

Chiappe, Luis M., Shu-An, Ji, Qiang, Ji, Norell, Mark A. (1999) "Anatomy and systematics of the Confuciusornithidae (Theropoda:Aves) from the Late Mesozoic of northeastern China" "Bulletin of the American museum of Natural History no.242 89pp.

Elzanowski, A. (2002) "Biology of basal birds and the origin of avian flight". In: Zhou Z., Zhang F. (eds) Proceedings of the 5th Symposium of the Society of Avian Paleontology and Evolution, Beijing, 1–4 June 2000. Science, Beijing, pp 211–226

Wogelius, R.A., Manning, P.L., Barden, H.E., Edwards, N.P., Webb, S.M., Sellers, W.I., Taylor, K.G., Larson, P.L., Dodson, P., You H., Da-qing L., and Bergmann, U. 2011. Trace metals as biomarkers for eumelanin pigment in the fossil record. Science, 333(6049): 1622-1626.

Zhou Z. and Farlow, J.O. (2001) "Flight capability and habits of Confuciusornis". In: Gauthier and Gall (eds). New perspectives on the origin and early evolution of birds: proceedings of the international symposium in honor of John H. Ostrom. Peabody Museum of Natural History. Yale University, New Haven. pp. 237–254

Yutyrannus: Beast of the Week

This week we will be checking out a dinosaur that changed the way we think about feathers.  Enter Yutyrannus huali!

Yutyrannus was a meat-eating dinosaur that lived in what is now China during the early Cretaceous Period, about 125 million years ago.  It was large, measuring about thirty feet from snout to tail as an adult.  The genus name, Yutyrannus, translates to "Feathered Tyrant" because, as you're about to learn, it had feathers!

Yutyrannus life reconstruction by Christopher DiPiazza.

Yutyrannus belonged to the tyrannosauroid group, and was closely related to other dinosaurs like Guanlong, Eotyrannus, and Dryptosaurus.  Like them, it had characteristic curved, serrated teeth, and strong front arms, each tipped with three hooked claws.  It's later relatives would eventually develop the well-known two-fingered front limbs, best known in its slightly more distant relative, Tyrannosaurus.  Adult Yutyrannus also possessed a short horn in front of each eye and a ridge-like bony crest running down the top of its snout.  These features may have been used for combat or display within its species.  Yutyrannus had strong legs, but its foot bones were relatively short compared to those of some other theropods, suggesting it wasn't an extremely fast runner in life. It may have been better at ambushing, and then using its size and power to take down prey, rather than chasing it very far.

Yutyrannus cast mounted at the American Museum of Natural History in New York.

Yutyrannus' real claim to fame, however, is the fact that we know for certain it had feathers.  This is due to actual visual presence of fossilized feathers found on the remains of the three specimens that were found.  Because of the placement of these feathers, which includes the bottom of the pelvis, the tail, the arms, and the ankle, it is likely that Yutyrannus had a more even coat of plumage over most of its body in life.  This evidence makes Yutyrannus the largest dinosaur known to date with actual fossilized feathers.  (Other large dinosaurs, like Deinocheirus, show evidence of having had feathers by having a pygostyle, but not actual fossilized feathers found with its bones, which is what we have with Yutyrannus.)  These feathers weren't preserved well enough to tell exactly what kinds of feathers they were, but they most likely would have been somewhat shaggy in life, similar to those on modern ground birds, like emus or kiwis.

Shaggy kiwi.  If you're even in Washington D.C., check these guys out at the National Zoo.

So why feathers?  This is the first question that many people ask when learning about Yutyrannus.  A better question might be "why not feathers?"  Feathers are a versatile adaptation.  They can keep an animal warm when the environment is cold, but also cool when the environment is too hot.  They also serve as protection against the elements like precipitation or the sun, can help camouflage by obscuring the animal's basic body shape, and can aid with communicating to other members of the same species in a visual and/or behavioral way.  Thanks to finding Yutyrannus, we now think it is possible, and maybe even likely that tyrannosauroids all had feathers in some form, including T. rex.

Preserved feathers on the ankle (you can see the bones on the left) of Yutyrannus on display at the American Museum of Natural History in New York.

If you live in the New York / New Jersey area you can come see a  cast of the famous Yutyrannus fossil, as well as remains (casts and real fossils) of many other important feathered dinosaurs at the American Museum of Natural History's seasonal Dinosaurs Among Us exhibit, which closes in January, 2017.  Maybe I'll see you there!  That is all for this week.  As always feel free to leave a comment below or on the facebook page.

References

Xu, X.; Wang, K.; Zhang, K.; Ma, Q.; Xing, L.; Sullivan, C.; Hu, D.; Cheng, S.; Wang, S.; et al. (2012). "A gigantic feathered dinosaur from the Lower Cretaceous of China" Nature 484 (7392): 92–95.

Gigantoraptor: Beast of the Week

This week we will be taking a look at a dinosaur that gave paleontologists valuable information about fossil eggs, and the modern bird connections to prehistoric dinosaurs!  Enter Gigantoraptor erlianensis!

Gigantoraptor with nest life reconstruction by Christopher DiPiazza.

Gigantoraptor was an oviroraptorosaur theropod dinosaur that lived in what is now Mongolia, during the Late Cretaceous, about 70 million years ago.  It's name translates to "Giant Thief/Hunter" in reference to the fact that at a whopping twenty six feet long, it was much larger than other members of it's clade, like Oviraptor, Anzu, and Citipati.  Gigantoraptor is only known from one partial skeleton which was found to be still growing, so this dinosaur could have have been even larger as an adult.

Gigantoraptor skeletal mount on display in Japan.

Like its relatives, Gigantoraptor had a short, but deep and powerful beak, somewhat similar to a parrot's.  We know this thanks to a well-preserved lower jaw.  Sadly no upper skull has been found from Gigantoraptor yet.  What it used this beak to eat is still a total mystery.  It may have used it to crack open nuts or clip vegetation. Perhaps it was a meat-eater, as well, and used it to break bones?  Gigantoraptor also possessed three hooked claws on each hand and stood on two long, powerful legs.  For an animal its size, it was likely a fast runner.  Although there is no direct fossil evidence of it, Gigantoraptor almost certainly had feathers.

Eggs likely laid by Gigantoraptor with embryo skeleton.

Another really interesting thing about Gigantoraptor is the fact that paleontologists also have discovered its eggs! (and if they arent from Gigantoraptor they are from something EXTREMELY close to it.)  The eggs in question are almost cylindrical in shape, and each measure over twenty inches long!  Some of these eggs were carefully opened to reveal the bones of an oviraptorosaur embryo inside.  The eggs were discovered arranged in a ring formation.  This is typical for what we know about oviraptorosaur nest, thanks to relatives like Citipati, which were found actually brooding over the eggs laid in the exact position.  Gigantoraptor also would most likely have sat in the middle of this ring of eggs with its arms (which had feathers in life) spread over them for protection.  Within the ring of eggs, the eggs seem to have been laid in groups of two.  This is really important to know since it supports the idea that Gigantoraptor, along with many other egg-laying animals, possessed two oviducts in life.  Modern birds, and a few very bird-like nonavian dinosaurs are the only ones that have actually lost one of their oviducts as they evolved. (and do not pair their eggs as they lay them)  We used to think that birds developed this asymmetrical trait to become lighter and fly, but that doesn't explain why flightless dinosaurs like the troodontids evolved the same feature.

That is all for this week!  As always feel free to comment below or on our facebook page!

References

Wiemann J, Yang T, Sander PNN, Schneider M, Engeser M, Kath-Schorr S, Müller CE, Sander PM. (2015) The blue-green eggs of dinosaurs: How fossil metabolites provide insights into the evolution of bird reproduction. PeerJ PrePrints 3:e1323 https://doi.org/10.7287/peerj.preprints.1080v1

Xu, X.; Tan, Q.; Wang, J.; Zhao, X.; Tan, L. (2007). "A gigantic bird-like dinosaur from the Late Cretaceous of China". Nature 447 (7146): 844–847.