Sunday, December 29, 2013

Giraffatitan: Prehistoric Animal of the Week

It's the last Prehistoric Animal of the Week of the year!  Lets go out BIG!  Enter Giraffatitan brancaiGiraffatitan was a sauropod dinosaur that lived in what is now Tanzania, Africa during the late Jurassic about 150 million years ago.  This plant-eater was huge, amongst the largest land animals of all time.  The largest known specimen of Giraffatitan would have been about eighty five feet long!  The name, Giraffatitan, translates to "Giraffe Titan/Giant".  This is in reference to its long neck and front limbs which are similar to those of the comparably puny and unrelated modern giraffe.

Giraffatitan brancai life reconstruction by Christopher DiPiazza.

This dinosaur's long neck and legs would have been used to help it gain access to more vegetation high in the trees, which it would have eaten using its chisel-shaped teeth lining the front of it's mouth.  Since it didn't have any teeth designed for chewing in the back of its mouth, Giraffatitan, like many sauropods, would have swallowed mouth-fulls of foliage whole.  Unlike other kinds of sauropods like Apatosaurus or Barosaurus, Giraffatitan wouldn't have been able to rear up on its hind legs because it's center of gravity was near its chest and shoulders, not its hips.  This anatomical characteristic is common to all members of Giraffatitan's family, called Brachiosauridae.

Giraffatitan skull.  See the nostril holes?

Another interesting characteristic of Giraffatitan's anatomy is it skull, which possesses nostril holes on its forehead that form a crest.  Scientists used to believe that Giraffatitan, along with all other sauropods, lived a semi-aquatic lifestyle and that the nostril placement was for snorkeling.  We now know this is false since the water pressure would likely prevent the dinosaur who's chest was that far beneath the surface from breathing.  Another idea suggested that Giraffatitan would have had a trunk since modern mammals with high nostril placement, such as tapirs and elephants, have trunks.  This hypothesis is likely false as well because a sauropod's teeth were designed for grasping food and some fossilized specimens even show wear from it.  Why would it need a trunk?  Both elephants and tapirs have chewing teeth in the backs of their mouths.  According to the most recent studies, it is most likely that Giraffatitan would have had fleshy nostrils near the tip of its snout when it was alive.

Giraffatitan skeletal mount on display in Germany.

Giraffatitan used to be called Brachiosaurus and was one of two known species within its genus.  In fact, most reconstructions labelled as "Brachiosaurus" are based on Giraffatitan remains.  It was realized that the animal now referred to as Giraffatitan and the other animal that used to share a genus with it, Brachiosaurus altithorax, had enough morphological differences so the genus was split.  Giraffatitan was named and Brachiosaurus is now only a single species. 

That's all for this week!  As always comment below or on our facebook page.  See you inn 2014!

References

Russell, D., Béland, P. and McIntosh, J.S. (1980). "Paleoecology of the dinosaurs of Tendaguru (Tanzania)." Mémoires de la Societé géologique de la France, 59: 169-175.

Taylor, M.P. (2009). "A Re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropod) and its generic separation from Giraffatitan brancai (Janensh 1914)." Journal of Vertebrate Paleontology, 29(3): 787-806.

Witmer, L.M. (2001). "Nostril position in dinosaurs and other vertebrates and its significance for nasal function". Science 293 (5531): 850–853. doi:10.1126/science.1062681. PMID 11486085.

Sunday, December 22, 2013

Pachyrhinosaurus: Prehistoric Animal of the Week

This week belongs to a unique ceratopsid dinosaur, PachyrhinosaurusPachrhinosaurus was a very successful plant-eater that lived in what is now Canada and Alaska during the Late Cretaceous.  There are actually three species within this genus that range in age from 73 million to about 69 million years old.  Pachyrhinosaurus was amongst the largest of ceratopsids, the biggest specimen measuring over twenty feet long.  The name, Pachyrhinosaurus, translates to "Thick Nose Dinosaur" because of its head ornamentation.  While many other ceratopsids had horns growing from their noses and brows, Pachyrhinosaurus had a wide, flat structure called a boss.  It did have horns on its frill, however.

Pachyrhinosaurus lakusai adult and young by Christopher DiPiazza.

Pachyrhinosaurus is a well-studied dinosaur, known from many specimens.  In fact, there were over a dozen skeletons of this dinosaur all discovered together in the same area in Alberta, Canada, called Pipestone Creek.  It is possible that the poor dinosaurs died trying to swim across a river that had flooded.  Amongst these specimens there were small juveniles all the way up to large adult animals.  This tells us that Pachyrhinosaurus was a dinosaur that, at least sometimes, lived in groups and most likely looked out for its young.

Pachyrhinosaurus lakusai skeletal mount

When alive, Pachyrhinosaurus would have co-existed with many other dinosaurs including Edmontosaurus regalis and the tyrannosaurid, Albertasaurus to name just a few.  Pachyrhinosaurus belongs to a group, or subfamily, called centrosaurinae within ceratopsidae.  Centrosaurine ceratopsids tended to have taller, thicker snouts, longer tails, and shorter frills than other large ceratopsids.  They also typically (not always) were devoid of long brow horns and instead sported large, bony structures on their snouts.  Other examples of centrosaurine ceratopids are Styracosaurus and Nasutoceratops.

Pachyrhinosaurus character from the new Walking With Dinosaurs 3D movie.

Pachyrhinosaurus is the star of the new movie, Walking With Dinosaurs 3D which came out in theaters just this past Friday!  The dinosaurs in this movie are amongst the most scientifically accurate to date since many paleontologists were consultants.  I haven't seen it yet but I definitely am planning to go within the next few weeks.  Pachyrhinosaurus is no newcomer when it comes to pop culture, however.  A few years back it was featured on a Canadian Coin that glows in the dark!

Shiny and glowy oohhh ahhhh!  The artwork on this coin was done by paleo-artist, Julius Csotonyi.

That's all for this week!   Join us next week for the last prehistoric animal review of 2013!  As always feel free to comment below or on our facebook page! 

References

Anthony R. Fiorillo and Ronald S. Tykoski (2012). "A new species of the centrosaurine ceratopsid Pachyrhinosaurus from the North Slope (Prince Creek Formation: Maastrichtian) of Alaska". Acta Palaeontologica Polonica 57 (3): 561–573. doi:10.4202/app.2011.0033.

C. M. Sternberg. 1947. New dinosaur from southern Alberta, representing a new family of the Ceratopsia. Geological Society America Bulletin 58:1230

Currie, P.J., Langston, W., and Tanke, D.H. (2008). "A new species of Pachyrhinosaurus (Dinosauria, Ceratopsidae) from the Upper Cretaceous of Alberta, Canada." pp. 1-108. In: Currie, P.J., Langston, W., and Tanke, D.H. 2008. A New Horned Dinosaur from an Upper Cretaceous Bone Bed in Alberta. NRC Research Press, Ottawa, Ontario, Canada. 144 pp. ISBN 978-0-660-19819-4

E. B. Koppelhus. 2008. Palynology of the Wapiti Formation in the northwestern part of Alberta with special emphasis on a new Pachyrhinosaur bonebed. International Dinosaur Symposium in Fukui 2008: Recent Progress of the Study on Asian Dinosaurs and Paleoenvironments. Fukui Prefectural Dinosaur Museum, Fukui 65-66.

Thursday, December 19, 2013

Holiday Time at the Zoo 2013

This will probably be my last post before Christmas! This year my gift to you is a video of an Andean Condor (a dinosaur) getting a box stuck on his head.  Every December at the zoo I work at we give out wrapped presents to the animals (in this case some dead mice).  Enjoy.


Nothing spreads Christmas cheer like a giant flesh-eating bird getting a flamboyantly wrapped box stuck on his noggin.  Am I right or am I right?  Happy Holidays from Jersey Boys Hunt Dinosaurs!

Sunday, December 15, 2013

Europelta: Prehistoric Animal of the Week

This week goes to yet another new species, Europelta carbonensis!  First described only a few weeks ago, Europelta was an ankylosaur, a kind of plant-eating dinosaur with thick, bony armor on its body, like Ankylosaurus or Gargoyleosaurus.  It lived in what is now Spain during the Early Cretaceous, 112 million years ago.  The name, Europelta carbonensis, translates to "European Shield from the Coal" since it was discovered in a coal mine.  Europelta is considered a medium-sized dinosaur, measuring fifteen feet long from snout to tail. 

Life reconstruction of Europelta carbonensis by Christopher DiPiazza

Europelta is the most complete ankylosaur ever to be discovered in Europe and is known from two partial skeletons.  Between the two specimens, most of the bones are known.  Europelta is a member of the family called nodosauridae.  Nodosaurids were ankylosaurs that typically had sharp, flattened protruding pieces of armor running down their flanks and no club weapon on the tip of the tail.  Europelta, like other nodosaurids, also had a broad plate of bony armor covering the top of its pelvis called a sacral shieldEuropelta is the oldest known member of the Nodosaurid family.

Skull pieces of Europelta

Europelta possessed some unique physical characteristics.  Two of its pelvis bones, the pubis and ischium, were fused together to form one bone, called an ischiopubis.  Also, Europelta had proportionally longer front limbs than what is typically seen in other ankylosaurs. Its teeth were small and possessed tiny leaf-shaped serrations for cutting plant material, similar to those of other ankylosaurs. 

Some of the pieces of armor, called osteoderms, from Europelta.

That's all for this week!  Join us next week as we check out a dinosaur we will all be able to see on the silver screen soon!

References

Kirkland, J. I.; Alcalá, L.; Loewen, M. A.; Espílez, E.; Mampel, L.; Wiersma, J. P. (2013). "The Basal Nodosaurid Ankylosaur Europelta carbonensis n. gen., n. sp. From the Lower Cretaceous (Lower Albian) Escucha Formation of Northeastern Spain". In Butler, Richard J. PLoS ONE 8 (12): e80405. doi:10.1371/journal.pone.0080405.

Friday, December 13, 2013

Fleshy Crest: Edmontosaurus Had One

The dinosaurs referred to as the "duck-billed", the hadrosaurs, are amongst the most extensively studied of all the extinct dinosaurs.  Thanks to so many of their remains that have been found, we know how they nested, that they cared for their young, how fast they grew, what some of their organs were like, what they ate, and what their skin and scales looked like.  That is a LOT more than what we can say about any other kind of prehistoric dinosaur! 

Recently, yet another wonderfully preserved hadrosaur specimen has been uncovered in Alberta, Canada that preserved a lot of soft tissue around the neck and head.  This hadrosaur was Edmontosaurus regalis, a close, earlier relative to Edmontosaurus annectens.  Since it's original discovery, Edmontosaurus was considered sort of a typical, basic hadrosaur.  It had the wide, flat bill but unlike some of its relatives, it sported no fancy crest on its head...except it actually did.

Image from the new paper showing where the crest is on the specimen by the white arrows.


You see, the crest of Edmontosaurus was kept a mystery for so long because it wasn't made of bone like the crests of so many of its relatives such as Parasaurolophus or Tsintaosaurus.  The crest of Edmontosaurus regalis was made of just skin so it would have rotted away rather quickly before the fossilization process could have happened.   Luckily this particular specimen retained it!  It was probably full of blood vessels and would have been soft, maybe even floppy, in life.  This sort of thing isn't unheard of in living relatives, either.  Just look at birds like chickens and turkeys for instance.  Some lizards, like Green Iguanas and certain agamids have soft crests as well.

My quick sketch-and-paint of Edmontosaurus ragalis' new look.

So why would a dinosaur evolve such a thing?  Well, the easy answer could always be display.  (When in doubt just say display.)  It's why a lot of extant animals have them.  It could be possible that only the males had them, or possibly had larger ones which would go along with what you would find in chickens and iguanas.  A soft crest like that could also help regulate the animal's body temperature.  Within the crest, blood would be closer to the outside air, and cool off more easily.  Then this blood would be circulated back into the body, thus helping to cool the whole animal off.  Chickens do this with their crests, called crowns, and many mammals also do this with their ears.  This is why a lot of desert mammals have large ears.

All of these animals use body parts made of soft tissue for either display and/or thermoregulation.  It is possible Edmontosaurus evolved its soft crest for similar purposes.

Although this is pretty exciting, this doesn't in any way make up for the fact that Tsintaosaurus lost its hilarious penis-shaped crest.  Nice try, science, but I'm still mad at you!

References

Bell, Fanti, Currie & Arbour. 2013. A Mummified Duck-Billed Dinosaur with a Soft-Tissue Cock’s Comb. Current Biology http://dx.doi.org/10.1016/j.cub.2013.11.008

Monday, December 9, 2013

Siats: Prehistoric Animal of the Week

Allow me to apologize for the delay.  Yesterday I had been on a plane and when I arrived home I sat at my computer to complete this post...and fell asleep at the keyboard.  Normally I sleep on planes but that time I had not for some reason.  Again I apologize.

This week belongs to yet another recently discovered dinosaur!  Only described last month, check out Siats meekerorumSiats was a large, meat-eating dinosaur that lived in what is now Utah, USA, and lived during the middle Cretaceous period, about 98 million years ago.  The individual found would have been about thirty feet long from snout to tail.  Experts believe this specimen was only a juvenile, however, and that Siats could have pushed forty feet as a fully grown adult!  Its genus name is after a man-eating monster from the local Native American mythology, called a siats. 

How a living Siats meekerorum may have looked.  Illustration by Christopher DiPiazza.

Unfortunately the known remains of Siats are only fragmentary but enough bones were salvaged for experts to identify it as a member of the the allosauroid family.  It would have been closely related to dinosaurs such as Acrocanthosaurus, and to a lesser extent, Allosaurus and Saurophaganax.  These predatory dinosaurs typically had three fingers on each hand tipped with long hook-shaped claws.  They also had serrated blade-like teeth adapted for slicing chunks of meat off carcasses...or still living victims.

Some of the bones unearthed belonging to Siats.

Siats was an important find because of its allosauroid status.  All the known large predatory dinosaurs from later times in North America were Tyrannosauroids like Teratophoneus, Lythronax and eventually at the very end of the Cretaceous, Tyrannosaurus rex to name just a few.  All the large predators known before it, however, were other allosauroids.  Before the discovery of Siats, the middle Cretaceous of North America was sort of a mystery ecosystem which paleontologists had not found many fossils from at all.  Siats brings us one step closer to knowing what it was really like back then by telling us that allosauroids were going strong and were as big as ever at least until 98 million years ago. 

That's all for this week!  Join us next Sunday for another prehistoric animal of the week!  Hopefully it will be yet another newly discovered species!  (if I can paint it fast enough)  As always comment below or on our facebook page!

References

 Zanno, L. E.; Makovicky, P. J. (2013). "Neovenatorid theropods are apex predators in the Late Cretaceous of North America". Nature Communications 4. doi:10.1038/ncomms3827.

Thursday, December 5, 2013

Concept Sketches: Reveal

Two weeks ago I shared with you some of my concept sketches that would later give rise to actual paintings.  Then I said I would reveal which paintings specifically they were in the following week...which I did not because it was Thanksgiving and I was busy with family stuff.  Sorry. 

Lets check out the results!

The first sketch I showed you actually included three now completed paintings.



 This sheet included...









Here they are all next to their original sketches!



Then I showed you this page which had a bit more going on.




It included...





Protoceratops (humping)...



 

Again, here they are with their sketches as well.


Sunday, December 1, 2013

Tsintaosaurus: Prehistoric Animal of the Week

Today, we are looking at Tsintaosaurus spinorhinus!   Tsintaosaurus lived in what is now China during the Late Cretaceous, about 70 million years ago.  Its name translates to "Tsintao (city in China where it was discovered, now called Qingdao) Lizard Spike Nose".  It was a hadrosaur, or "duck-billed dinosaur", sporting the typical broad bill in the front of its skull and hundreds of small teeth in the back of its mouth to help it eat plants.  Tsintaosaurus measured about thirty feet long from snout to tail and could have walked on all fours or just its hind legs if it needed to. 

Tsintaosaurus skeletal mount.

There were many interesting hadrosaurs sporting fancy crests atop their skulls.  The function of these crests has been explained on here before.  When the remains of Tsintaosaurus were first discovered back in the nineteen fifties the skull had a long, skinny, rod-shaped piece of bone jutting out from the front.  It sort of looked like a unicorn's horn...or an erect penis.  Then paleo-artists from across the globe got together and had a big, fancy, official paleo-artist meeting where they agreed to ALWAYS depict Tsintaosaurus having two round, inflatable air sacs under its crest so that the whole thing looked like an erect penis and testicles dangling atop the poor creature's face.  They also all agreed to make Tsintaosaurus green...ALWAYS green.  Seriously, google search images of Tsintaosaurus.  All you will get is green dinosaurs with bright orange or yellow dongs on their heads.  (I am also guilty of having colored this animal green in a reconstruction from 2010 but I was pretty reserved on the testicle sacs trend I am proud to say.)

Nothing but green dinosaurs with dick-and-balls crests all around.  Big photo is of the hilarious plastic model by the company, CollectA.  It's pretty much the crowned jewel of my plastic dinosaur collection.

Tsintaousaurus proudly rocked this phallic crest until the early nineties when a few paleontologists proposed that this rod-shaped piece of bone was actually supposed to be attached to the snout and had just gotten bent and warped during the fossilization process.  For a few years after that poor Tsintaosaurus had no interesting crest at all until more specimens were discovered, all sporting the same pointy unicorn crests.  This proved that it was not just a part of the snout after all.  Yay!

Diagram of a more complete Tsintaosaurus skull from the 2013 paper.

It wasn't until a few weeks ago in 2013 that information was released about some new Tsintaosaurus fossils that were found.  As it turns out, there were actually a lot of missing pieces that would have attached to the original rod-shaped bone which was only one part of a bigger, more complex structure.  Tsintaosaurus in reality would have had a more broad, curvy crest that started at the snout and went all around behind the head.  It looks like the pope's hat.  If the term "pope dinosaur" catches on to describe Tsintaosaurus remember, you heard it here first!

I illustrated a little timeline.

This most recent discovery tells us more about Tsintaosaurus than just how it looked.  The new crest bones suggest that Tsintaosaurus would have had hollow chambers within for making loud noises much like the mechanics of a brass musical instrument.  Previously it was believed that Tsintaosaurus may have been related to hadrosaurs with solid crests devoid of hollow chambers and tubes or no crests at all.  We now think it was closer to hadrosaurs like Parasaurolophus which did possess hollow tubes within a large crest.

All that being said I decided to paint an updated reconstruction of Tsintaosaurus with the new crest and no hint of green whatsoever!  Behold!

Tsintaosaurus spinorhinus by Christopher DiPiazza.

That's all for this week!  As always please comment below or on our facebook page.

References

Prieto-Márquez, A.; Wagner J.R. (2013). "The ‘Unicorn’ Dinosaur That Wasn’t: A New Reconstruction of the Crest of Tsintaosaurus and the Early Evolution of the Lambeosaurine Crest and Rostrum.". PLoS ONE 8 (11): e82268. doi:10.1371/journal.pone.0082268. Retrieved 23 November 2013.

Young, C.-C., 1958, "The dinosaurian remains of Laiyang, Shantung", Palaeontologia Sinica, New Series C, Whole Number 42(16): 1-138