Wednesday, April 26, 2017

Prehistoric Beast of the Week Visits Jurassic World: The Exhibition

I have been living in Philadelphia, Pennsylvania, for almost seven months now.  When I first moved here I caught wind of the Franklin Institute opening a seasonal exhibit that simulates visiting Jurassic World with life-sized animatronic dinosaurs.  I knew I had to go see it.  After being open to the public since November, I finally had a chance to go check it out in person.


If you are not familiar with it, simply put, the Franklin Institute is a museum dedicated to science education, especially towards young visitors.  Every exhibit in there has some sort of hands on aspect for everyone to try, all the while pelting you mercilessly with information to fill your brain with for days...if you actually bother to read.  (I will never understand people who just walk through museums and zoos without actually reading things.)  That being said, I was very interested to find out how a place that prides itself on science education would handle an exhibit from a franchise that honestly... kind of hindered science education.  I know that sounds harsh, but it's true, at least when it came to Jurassic Park 3 and the latest Jurassic World.  Too many people have had their image of dinosaurs warped because the Jurassic Park franchise is their only real exposure to the subject.  Too many people don't understand that many dinosaurs, let alone Velociraptor, were just as feathered as modern birds.  Too many people still think Dilophosaurus could spit venom and had a retractable frill.  Too many people still think Tyrannosaurus had vision based on movement....I could go on.  THAT BEING SAID I don't think the Jurassic Park franchise has a responsibility to uphold scientific accuracy.  I will never be one of those nerds blasting on the internet all the inaccuracies of the Jurassic Park movies and how they could have been "better".  There are enough of those folks out there.  I understand the franchise's purpose is to entertain, which it succeeds in doing, and I'm fine with that!  Would I like it if it was scientifically accurate?  Of course.  But I don't expect it to be.  I would much rather attack Discovery Channel, History Channel, and Animal Planet when they mess up paleontology programs because they actually advertise as being educational.  I was simply curious to see how Franklin Institute handled this exhibit.  Will they submit and have something in there that is just for thrills?  Or will they find a way to make it actually educational, even though the dinosaurs would not be?  Let's find out.

First thing I noticed was how long the line to get into the exhibit was.  The line starts on one floor, goes around a few zigzags, goes up a gradual ramp, then up to a different floor...and then you are waiting in a room that is supposed to be the inside of the ferry boat from the movies for a while until everyone fills it.  Then you watch a short introduction movie.  Very reminiscent of something I'd expect to wait on at Universal Studios or Disney World.  Finally the door opens, you push some kids out of the way to get in first, and you see your first dinosaur...

Despite the fact that it's Jurassic World: the Exhibition, this exhibit incorporated elements from all the movies to a certain degree.  A good example of this was Brachiosaurus, which was featured in the first film, but not Jurassic World.  Since Brachiosaurus was so large, and a robot of its whole body couldn't fit inside the exhibit, they cleverly only showed this dinosaur from the shoulders up, and portrayed it as if it were bathing in a lake.  The neck still towers over you and the head comes just low enough so a average-sized adult could be a few inches shy of poking it with an outstretched finger. (not like I tried or anything.)  In front of the dinosaur, were screens, and plaques, with information...good information!  The short movie on loop explained how sauropods likely weren't using their nostrils as snorkels underwater like previously thought, and could probably only wade in water up to a certain point.  They also discussed how sauropod bones were filled with air sacks, making their bodies lighter, which was the key to them evolving so large.

Sorry my photo is blurry.  She wouldn't stop moving.

A few steps further you meet Parasaurolophus, also in the form of shoulders, neck, and head, this time peering out from thick foliage.  This duck-billed dinosaur was in Jurassic World, but it was also in the first movie, seen from a distance with Brachiosaurus, and was most prominent in the second movie, The Lost World: Jurassic Park.  The Parasaurolophus animatronic for this exhibit has a short crest, leading me to wonder if it was based on the Parasaurolopus cyrtocristatus species.  It is also possible it was meant to represent a female of one of the two long-crested species, which some have suggested had shorter crests than males, but this hasn't been proven.

A Parasaurolophus and a fiance pose for a photo. 

The next room showcases beautiful animatronic models of an adult and baby Pachyrhinosaurus.  I'm not sure why they didn't opt for Triceratops, the ceratopsian that was actually featured in all the Jurassic Park movies, but I'm not complaining.  I'm all for lesser-known genera getting public attention.  Pachyrhinosaurus was also the only dinosaur showcased in this exhibit that was not in any of the Jurassic Park movies.  (although it is in the mobile game and was made into an action figure in 2014)  Despite this, I think these were the most well done models in the exhibit.  They were very close to scientifically accurate.  My only nitpicks would be their size was a bit too large, and the fact that their front limbs had claws on all five digits (should be the first three only).  I would have personally changed the skin texture to match that of what we know from mummified remains of other ceratospians, but Pachyrhinosaurus, itself, has never had skin preserved on the fossil record. (that I know of)  Beyond that they were awesome models.  The baby Pachyrhinosaurus was impressive because the horn ornamentation matched what is known from actual fossilized baby Pachyrhinosaurus that have been found, possessing a much smaller nose boss and horns.  To go with this, there was an interactive plaque with light up buttons where you can match the baby ceratopsian skull shape with its adult counterpart.  This was my favorite part of the exhibit from an educational standpoint.  (I'm also biased towards ceratopsians.)

The Pachyrhinosaurus were arguably the best models in this exhibit.

After this you are funneled into a room that is meant to look like a laboratory.  Here, if you bother to read, they actually go into the science of fossilized amber, and how insects get caught in them.  (Nevermind the fact that you almost certainly can't get dinosaur DNA from them.)  There are a number of other fun, interactive, touchscreen activities.  My favorite was one where you can apply your own color scheme to one of several 3D dinosaur models.  Throughout this process, the program explains to you why dinosaurs may or may not have had certain colors and patterns.  In the middle of the room was an incubation chamber with three animatronic sleeping baby Parasaurolophus.  All of them had breathing animatronics and every few minutes the middle one would groggily lift its little noggin, blink, open its mouth, then put its head down to go back to sleep.  As cute as they were, the nerd inside me was disappointed that their crests were too long!  Paleontologists have actually unearthed an real baby Parasaurolophus skeleton, and we now can confirm that the crest started out almost nonexistent (barely a nub on the top of the skull) and would become the shape that the adults had as the individual reached sexual maturity.

Look at those pleepin babies! (I spelled "pleepin" correctly.  This is baby talk.  Learn it.)

Then smaller groups of people are put into a space with a large cage on one side of the room.  This is where you get to come face to face with Blue, the Velociraptor!  Blue comes out in the form of an actor wearing one of those increasingly popular dinosaur puppet-costumes, which are actually really life-like if the actor inside knows what he/she is doing.  Blue will pace around in the cage a few times, sniff/snap at some kids in the front, then go back through a door in the back of the cage, all the while audio of Chris Pratt is being played sating things like "Easy!" and "Back up, Blue!".  During this show, a woman on the monitor (the "head keeper") is saying information about Velociraptor in general.  She uses the term dromaeosaur, to reference the group it belonged to, which is good.  It's mildly annoying hearing people call it the "raptor" group so much.  (I know some professionals who use the term "raptor" to refer to dromaeosaurs, but I personally detest it mainly because of the fact that modern birds of prey were called "raptors" first.  She also mentions that the second toe claw was the its "key to success" and allowed it to slash open prey.  This is possible, but not the only hypothesis for how dromaeosaurs used their toe claws.  Sadly I could not get a decent photo of this.  The room was dark and there were way too many people's heads in the way.

After the Velociraptor encounter you meet Tyrannosaurus.  The huge Tyrannosaurus animatronic (close to life size as far as I could tell...the head was a little large.) looms over the audience off to the side in a dark room, meant to look like her holding pen at night.  Then light affects simulate lightning and audio plays the sounds of thunder and dinosaur stomping as the dinosaur slowly marches out from her hiding spot.  She roars a few times and then appears to bump a parked jeep, which had a set of hydraulics set up under it so when the animatronic bends over and moves its head, the car will shake.  This whole section was definitely a recreation of the famous scene from the first Jurassic Park movie.


Sometime between the Velociraptor and T. rex, we get an "emergency" message on one of the monitors that something went down and nobody should worry. I wouldn't be Jurassic Park World without a dinosaur escape!

Then we get to meet Stegosaurus.  This is probably the most photogenic opportunity in the exhibit because the Stegosaurus model is the closest to you as the guest.  The Stegosaurus is pretty accurate to the movie Stegosaurus, and therefore has the same flaws when looking at it from a scientific standpoint, but it was still very cool and impressive for what it was.

The Stegosaurus is trying not to barf because she's single and bitter about it.

Finally you meed Indominus rex, the main antagonist from the Jurassic World movie.  If you don't know, this large carnivore, was supposed to be a hybrid between a Tyrannosaurus, VelociraptorMajungasaurus, a tree frog, a cuttlefish... and I think a few more.  Anyway, the animatronic for this beast pops up across the path from the Stegosaurus, the lighting in the whole room turns more red (dramatic) and both animatronics begin to thrash around and roar to imply that they are fighting without actually making contact with each other. The Stegosaurus' tail is strategically facing the Indominus from the start, so it really does look like it's warding off the predator with those spikes. Despite the fact that Stegosaurus was in the Jurassic World film, I am surprised they chose not to make a model of Ankylosaurus, instead, since in the movie, that is what Indominus actually had a battle with.  After a few minutes, there are sound effects of gun fire and the Indominous model stops moving, thus ending the walkthrough of animatronic dinosaurs.

Close up photo of Indominus rex after being gunned down.  Poor gal.

The last room before the gift shop was the most educational part, filled with maps and infographs of many different kinds of dinosaurs. (some of which had feathers in the illustrations!)  Ther were also more bone casts from real dinosaurs on display, including those of Plateosaurus, interestingly enough, having not been featured in any Jurassic Park movies, but again I'm not complaining.  Sadly, this is also the room where most of the visitors rushed through the most, having seen all the exciting action-packed parts.

Not the best picture but IT HAS FEATHERS so it's something.

In conclusion I think the Franklin Institute did the absolute best job they possibly could to implement as much educational value into a Jurassic World attraction as possible.  Sadly, most people don't stop to read infographs and plaques when there is a thirty-foot animatronic dinosaur a few feet away.  Nobody's fault!  One thing that I was mildly disappointed at was the fact that there was no love in the exhibit for mosasaur, or any pterosaurs, which had pretty big roles in the Jurassic World movie.  They even had flags and signs with them on it outside the exhibit!  I wasn't expecting them at first, but those stupid flags gave me a glimmer of false hope!

There was also a bin with what were almost certainly 3D printed dinosaur body parts that could be put together and taken apart for the kids to make their own hybrid monstrosities.  I wonder if there is a way to download these and print them, myself.  I'd love to have the Pachyrhinosaurus.

Sadly, at the time of me publishing this, the Jurassic World Exhibition will be finished at the Franklin Institute, but will open at the Chicago Field Museum in May!  If you get the opportunity to check it out, I highly recommend it for a fun, and educational (if you know where to look) experience!

Good thing I gave Indominus my fiance's purse otherwise we'd all be dead.  Not every day you get mugged by a dinosaur.

Sunday, April 23, 2017

Prenocephale: Beast of the Week

This week we will be checking out another dome-headed dinosaur.  Enter Prenocephale prenesPrenocephale was a plant-eating dinosaur that lived in what is now Mongolia, during the late Cretaceous, between 80 and 75 million years ago.  It would have measured roughly between six and eight feet long from beak to tail.  The genus name translates to "sloping head" because of the dramatic shape of this dinosaur's skull. 

Prenocephale life reconstruction by Christopher DiPiazza.

Being a member of the pachycephalosaurid family, the thick, rounded skull is not surprising.  However, within the group, Prenocephale had a particularly egg-like shape to its skull, which sloped dramatically towards the snout, which earned it's genus name.  On the top of the snout, Prenocephale had two rows of short horns that each turn into a wide, bar-shaped ridge above each eye.  This ridge, combined with the fact that it is attached to the rather extensive dome skull, would have given Prenocephale the appearance that it had a furrowed, "grumpy" look in life.  The back of the skull also has rows of small horns on either side.  As is the case with all pachycephalosaurids, it is uncertain as to what exactly Prenocephale was using this kind of skull for.  Perhaps they were using them as weapons?  Perhaps they were purely for show?  Maybe one day we will find out! 

Prenocephale skull cast.  This is part of my personal collection.  Clothespin for scale.

In addition to its dome and horns, Prenocephale has a few other notable features when it comes to its skull.  It's eye sockets are large, and face partially forward.  This tells us that it probably had good vision and could perceive depth in life.  It's beak was small, and very narrow, even compared to other known pachycephalosaurids.  This tells us that Prenocephale may have had a different preference of food, or perhaps had a different style of feeding in life.  Plant-eating animals with more narrow mouths tend to browse for specific leaves more, rather than simply sucking up any vegetation that was closest to their face.  The back of Prenocephale's jaws were lined with small teeth which would have been best at slicing up plants.

Sadly, only Prenocephale's skull was ever actually found, aside from a few small bones.  Therefore we still don't know exactly what the rest of its body looked like.  However, thanks to more complete skeletons of other, closely related, Pachycephalosaurids on the fossil record, it can be assumed that Prenocephale was an obligate biped, walking on two strong back legs, had relatively short front limbs, tipped with five short fingers at the end of each hand, had relatively wide hips for a dinosaur, and a tail that was thick and muscular at the base and thin and stiffened towards the end. 

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

References

Longrich, N.R., Sankey, J. and Tanke, D., 2010. Texacephale langstoni, a new genus of pachycephalosaurid (Dinosauria: Ornithischia) from the upper Campanian Aguja Formation, southern Texas, USA. Cretaceous Research, . doi:10.1016/j.cretres.2009.12.002

Robert M. Sullivan (2003). Revision of the dinosaur Stegoceras Lambe (Ornithischia, Pachycephalosauridae). of Vertebrate Paleontology: Vol. 23, No. 1, pp. 181–207.

T. Maryanska and H. Osmolska. 1974. Pachycephalosauria, a new suborder of ornithischian dinosaurs. Palaeontologia Polonica 30:45-102.

Sunday, April 16, 2017

Byronosaurus: Beast of the Week

Let's check out a little dinosaur that not only taught us about how non-avian dinosaurs laid eggs and made nests, but also further solidified just how close-knit their relationship to modern birds really was.  Enter, Byronosaurus jaffei!

Byronosaurus was a meat-eating dinosaur that lived between 80 and 75 million years ago in what is now Mongolia.  It was a member of the troodontid family, similar to its North American relative, Troodon.  An adult Byronosaurus would have measured roughly four to five feet long from snout to tail, based on what has been found of it.  The genus and species names are in honor of Byron Jaffe, who was an important supporter of expeditions by the American Museum of Natural History into Mongolia.  These expeditions yielded a wealth of important dinosaur fossils, Byronosaurus, being one of them.  When alive, Byronosaurus would have shared its environment with other dinosaurs, like Velociraptor, Protoceratops, Oviraptor, and Citipati.

Byronosaurus life reconstruction by Christopher DiPiazza.

Being a troodontid, Byronosaurus had long legs, including proportionally long metatarsals (foot bones), indicating it was a fast runner in life.  On each foot, like its relatives, the dromaeosaurs, it would have had a retractable talon on each second toe.  These "killer claws" weren't as large as those seen on dromaeosaurs, like Velociraptor, but they would have still been helpful when hunting at least small prey.  Byronosaurus also had large eye sockets, suggesting it possessed good vision and further suggesting it could have been nocturnal or crepuscular.  This would make sense given the fact that where it lived was a desert at the time.  Many desert animals tend to be active when the sun isn't at its brightest to avoid the extreme heat.  Byronosaurus also had a long, slender snout filled with small, needle-like teeth, which were not serrated.  This style of tooth is typically seen in animals that are adapted for grasping and holding small prey.  This is interesting, since other troodontids are known to have had serrated teeth, which were more adept at cutting meat, rather than grasping.  Having good eyesight, a long snout, needle-like teeth, and a proportionally smaller, retractable talon, all suggest Byronosaurus may have specialized in hunting small, bite-sized prey, like invertebrates, mammals, small reptiles, and possibly baby dinosaurs, when available.

Adult Byronosaurus skull from the Mongolian Academy of Science.  Note the small, pointed teeth and large eye socket.

Another amazing thing about Byronosaurus is that paleontologists have discovered its nests, eggs, and babies!  The nests consist of eggs that were partially buried under sand, and were arranged in a cluster.  Eggs laid in clusters like this are also seen today from birds.  This is not the same as other known theropod nests, like those of Gigantoraptor, or Citipati, where the eggs are neatly arranged in a ring, in groups of twos.  Eggs laid in twos tells us that the dinosaur had two functioning oviducts.  Byronosaurus' eggs, which were not laid in twos, suggests, the mother did not have two functioning oviducts.  She likely only had one, like her modern bird relatives.  That, alone, is cool, but this information tells us a LOT more about bird evolution if you dig a little deeper.  For so long, it was thought that the reason why modern birds lost function in one of their oviducts was to become lighter in order to fly.  However, Byronosaurus didn't fly...and its descendants didn't either until finally going extinct.  Remember, when Byronosaurus was alive, during the Cretaceous, flying birds had already evolved.  This means that having one functioning oviduct evolved earlier than the first bird from a common ancestor of both birds and troodontids, and was not for flight originally.  It was simply utilized by the birds, for that purpose at some point later.  Why did troodontids, like Byronosaurus need to loose function of one oviduct if they weren't flying?  We still don't know!

Byronosaurus nest and baby skeleton on display at the American Museum of Natural History in New York.

Relatively newly hatched baby skeletons of Byronosaurus are also on the fossil record.  At first, these tiny skeletons were thought to be baby Velociraptors.  It was then discovered that they were actually Byronosaurus as more material was unearthed.  What's interesting is that as babies, Byronosaurus did not have the characteristic long snouts that the adults had.  Their faces were much shorter, with proportionally large eyes.  This is a trait also seen in modern bird babies, as well.  Animals that look like this as babies are typically taken care of by their parents for a period of time after hatching.  Were Byronosaurus attentive parents, too, perhaps?  Maybe more fossils will tell us one day!

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

References

Bever, G.S. and Norell, M.A. (2009). "The perinate skull of Byronosaurus (Troodontidae) with observations on the cranial ontogeny of paravian theropods." American Museum Novitates, 3657: 51 pp.

Novacek, M.J., Norell, M.A, McKenna, M.C. and Clark, J.M, 1994, "Fossils of the Flaming Cliffs", Scientific American 271(6), 60-69

Norell, M.A., Makovicky, P.J. & Clark, J.M., 2000, "A new troodontid theropod from Ukhaa Tolgod, Mongolia", Journal of Vertebrate Paleontology 20(1): 7-11

Norell, Mark A.; Clark, James M.; Dashzeveg, Demberelyin; Barsbold, Rhinchen; Chiappe, Luis M.; Davidson, Amy R.; McKenna, Malcolm C.; Perle, Altangerel; Novacek, Michael J. (November 4, 1994). "A theropod dinosaur embryo and the affinities of the Flaming Cliffs dinosaur eggs". Science. 266 (5186): 779–782.

Tuesday, March 21, 2017

Livyatan: Beast of the Week

This week we will be voyaging back to the Miocene to observe an amazing whale.  Make way for Livyatan melvillei!

Livyatan was a large, toothed, whale that swam in oceans that covered what is now South America and Australia (likely most of the southern hemisphere given that range) during the Serravalian stage of the Miocene epoch, between thirteen and twelve million years ago.  However, teeth that appear to be from Livyatan, found in Australia are dated at only between five and six million years old, pushing this animal's success much further through time. (If it is, in fact, the same genus, and if not it's still from an extremely close relative.)  Only teeth and parts of the skull have been found, but based on this, experts have estimated the animal's body length to have been between forty four and fifty seven feet long from snout to tail.  The genus name is the Hebrew spelling of the word, Leviathan, which was an enormous sea monster from biblical mythology.  The species name, melvillei, is in honor of Herman Melville, the author of the classic novel, Moby Dick...which is about a huge whale...in case you didn't know.

Livyatan immobilizing a young megalodon shark.  Painting by Christopher DiPiazza.

Livyatan was in the same major family of whales as the modern Sperm Whale.  Sperm whales (which Moby Dick was based on) are the largest living toothed whales.  However, they only have teeth on the lower jaw.  Sperm Whales eat almost exclusively giant squid.  Unfortunately we don't know exactly how they hunt because a Sperm Whale has never been observed in the act due to the fact that they dive down too deep, where the squid live, for us to observe the hunting behavior.  We know large squid make up most of their diets, however, because humans used to hunt Sperm Whales for their oil and during dissection/butchering, squid have always been found upon cutting open the stomach.  We also see scars and marks from giant squid tentacles on the faces of many Sperm Whales from their prey fighting back before being consumed.


Livyatan, on the other hand, despite being a close relative to Sperm Whales, may not have behaved, let alone, hunted the same way as their modern family members.  One very striking difference is that Livyatan had proportionally larger, more robust teeth, and a full set of them at that, on the lower and upper jaws.  Some of these teeth measure fourteen inches long!  This suggests it was not a squid specialist.  The fact that the teeth are so large and thick, points to Livyatan being more of a hunter of larger, more general prey that it would utterly pulverize via monstrous bites.  This makes sense, since we know Livyatan coexisted with plenty of other large sea creatures, including seals, sea lions, sharks, dolphins, and slightly smaller whales.  That's right, Livyatan, may have been a hunter of other whales!  (Which isn't unheard of. Orcas do it all the time.)   I find it worth noting that Carcharodon megalodon, (the giant predatory shark that is most certainly NOT still alive today, despite what Discovery Channel's idiotic shows suggest) was a contemporary of Livyatan's.  It is likely that the two were competitors, being similarly-sized predators.  They may have even preyed on each other depending on the circumstances!

Cast of Livyatan's skull on display at the Museo di Storia Naturale e del Territorio, in Italy.

The rest of Livyatan's skull was shaped similarly to that of a modern Sperm Whales.  This suggests that in life it had a large mass of soft tissue taking up most of the front of it's head, called a spermaceti organ.  This body part is full of oil and fat that helps whales use echolocation to navigate underwater.  Because of this it is likely Livyatan could do the same.  It also probably used complex vocalizations to communicate to members of its own species, as well.

I did this quick sketch just to show how much of a whale's head can be soft tissue compared to the skull.  The Sperm Whale's (pictured on the left) iconic rectangular profile is due to soft tissue mostly. (I actually botched the Sperm Whale's profile.  The shaded blue soft tissue part should go beyond the tip of the jaws even.)  It is likely, judging by the skull, that Livyatan, pictured left, had something similar. 

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

References

Lambert, Olivier; Bianucci, Giovanni; Post, Klaas; de Muizon, Christian; Salas-Gismondi, Rodolfo; Urbina, Mario; Reumer, Jelle (1 July 2010). "The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru Nature466 (7302): 105–108. 

Norris, K.S. & Harvey, G.W. (1972). "A theory for the function of the spermaceti organ of the sperm whale". In Galler, S.R; Schmidt-Koenig, K; Jacobs, G.J. & Belleville, R.E. Animal orientation and navigation. NASA, Washington, D.C. pp. 397–417.

Tuesday, March 14, 2017

Sphaerotholus: Beast of the Week

This week we shall be checking out a relatively small, but successful round-headed dinosaur.  Say hello to Sphaerotholus!

Sphaerotholus, was a pachycephalosaurid dinosaur, related to the much more famous, Pachycephalosaurus, that lived in what is now North America, including New Mexico and Montana, USA, as well as Alberta and Saskatchewan, Canada, during the late Cretaceous period.  The genus includes three species, that together, spanned from 76 to 66 million years ago.  When alive, Sphaerotholus would have been a plant-eater and could have measured roughly six feet from beak to tail, based on the very fragmented fossil material that is actually known from it. (basically just the top of the skull.) We can also guess roughly how large it was by comparing it to more completely-known, similarly-sized pachycephalosaurids, like Prenocephale and StegocerasSphaerotholus' genus translates to "ball dome" in reference to the top of it's head...which was quite spherical.

Sphaerotholus goodwini, from New Mexico, life reconstruction by Christopher DiPiazza.

Unfortunately not too much is known from this dinosaur.  Despite the fact that there are three named species, all the specimens consist of fragments of the top of the skull and very little else.  What we do know, is that even for a pachycephalosaurid, it had a particularly rounded and thick skull.  The arrangement of nodes (small horns/bumps surrounding the dome) were arranged in a unique way, as well.  Interestingly, pachycephalosaurids actually exhibit quite a bit of variation amongst species when it comes to head ornamentation, and Sphaerotholus was at the derived end of this family tree, when it came to cranium thickness. Some experts have suggested that Sphaerotholus is should really be sunken into the same genus as a more completely known, close relative, called Prenocephale, which was native to what is now Mongolia, but so far the material from Sphaerotholus has proven to be different enough to hold this off for now.

Dorsal view photo of a Sphaerotholus buchholtzae dome, from Canada, held at the American Museum of Natural History, from Paterson's 2013 paper.  Arrows are pointing to injuries possibly from head-butting behavior.

So why such a thick skull?  This question has been asked and debated by paleontologists since the first pachycephalosaurid was discovered.  The knee-jerk conclusion was that these dinosaurs were using their heads as weapons to ram each other with, similar to the behavior seen in many horned mammals today, like goats and muskox.  In fact, the skulls of many of these pachycephalosaurids, including Sphaerotholus, have been found with injuries on them, in the form of small lesions on the tops of their domes that became infected and possible healed in life, suggesting they were, indeed smashing their noggins together.  However, some other paleontologists think that if these dinosaurs actually rammed their skulls in that way, it would seriously injure, or even kill both animals.  It is possible they still used their heads as weapons, but rather aimed for softer parts of their rivals' bodies, like the flanks, or maybe at shorter range, swinging their necks around like clubs, instead of ramming with a running start.  It is also possible the skulls were at least partially for display within the species, as signs of sexual maturity, or even sex. (Although we have no idea if the males and females actually looked different from each other at this time.  Remember, we only have dome tops!)

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

References

Carr T. E.; Williamson T. D. (2002). "A new genus of highly derived pachycephalosaurian from western North America". Journal of Vertebrate Paleontology. 22 (4): 779–801.

Longrich N. R.; Sankey J. T.; et al. (2010). "Texacephale langstoni, a new genus of pachycephalosaurid (Dinosauria: Ornithischia) from the upper Campanian Aguja Formation, southern Texas, USA". Cretaceous Research. 31: 274–284.

Mallon Jordan C.; Evans David C.; Tokaryk Tim T.; Currie Margaret L. "First pachycephalosaurid (Dinosauria: Ornithischia) from the Frenchman Formation (upper Maastrichtian) of Saskatchewan, Canada". Cretaceous Research. 56: 426–431.

Peterson, Joseph E., Collin Dischler, and Nicholas R. Longrich. "Distributions of Cranial Pathologies Provide Evidence for Head-Butting in Dome-Headed Dinosaurs (Pachycephalosauridae)." Docs.com. N.p., 16 July 2013. Web.

Tuesday, February 28, 2017

Platypterygius: Beast of the Week

This week we will be looking at a successful ichthyosaur.  Enter Platypterygius!

Platypterygius was a relatively large ichthyosaur, group of marine reptiles that converged with fish in their body shape, that could grow to be about twenty three feet long from snout to tail.  The genus encompasses several species that have been found around the world, including Australia, United States, Russia, Colombia, and Argentina.  That, alone, makes this creature a success story in the grand scheme of things.  However, it is when Platypterygius lived that makes it truly impressive.  Most ichthyosaurs lived during the Triassic and Jurassic.  It is thought by most that by the time the Cretaceous came around, the poor ichthyosaurs were outcompeted by newer forms of large marine reptiles like pliosaurs and mosasaurs.  But not Platypterygius!  This gritty reptile persisted all the way through to the late Cretaceous, 131 to 91 million years ago!

Platypterygius sp. native to what was once Texas, USA, life reconstruction by Christopher DiPiazza.  This genus is known to have eaten turtles in life.

Like its closest relatives, Platypterygius had the telltale ichthyosaur profile, which superficially resembles a combination of a tuna and a swordfish at first glance.  It had a long pointed snout, lined with sharp teeth.  It had four flippers that evolved from walking limbs millions of years prior.  The back flippers were proportionally much smaller than the front ones.  It likely had a tail fluke of some kind and dorsal fluke, as well.  It's eye sockets were relatively large so they were likely comfortable hunting in deep water where there was less light and/or during the night.  Platypterygius is defined by having more finger bones than what is typical of ichthyosaurs in its front limbs.  These bones are especially flat and widened to form the broad paddle appendage it used for swimming in life.  It is because of this specific morphology it earned its genus name, which translates to "flat wing".

Platypteregius americanus skeleton at the Royal Tyrrell Museum in Canada.  Photo by By Roland Tanglao

The earlier forms of Platypterygius that lived during the early Cretaceous were specialist hunters as far as we can tell, preferring to hunt fish and cephalopods. (like squid and ammonites)  These species, like Platypterygius hauthali, from South America (lived between roughly 131 and 125 million years ago), had relatively streamlined bodies and longer pectoral (front) flippers.  These are adaptations for fast swimming so they could pursue their quick-moving prey.  Millions of years later, however, we see a shift in strategy.  Species of Platypterygius that lived towards the end of the Cretaceous, like P. americanus (time range of 112 to 91 million years ago), were bulkier, with proportionally shorter flippers. Their teeth were also slightly larger and more robust.  In addition to differences in morphology, the later forms of this genus show evidence of hunting differently, too. Paleontologists have discovered remains of different kinds of prey in their stomach cavities, including bones from birds, and even sea turtles.  This paints a picture of an ichthyosaur that was less picky about what it considered prey, and was able to afford pursuing this wider menu with a little extra muscle at the price of speed.  Platypterygius managed to carve out a more generalist niche when its relatives were going extinct in reaction to increasing competition from other kinds of marine reptiles that were appearing during the Cretaceous, like pliosaurs and mosasaurs.

Platypteregius sp. tooth.  Photo by Nathan Van Vranken.

That is all for this week!  Special thanks to paleontologist, Nathan Van Vranken, who is currently finishing a new scientific publication on ichthyosaurs, including Platypterygius, for lending his brain to this post.  As always leave a comment below or on our facebook page!

References

Arkhangel’sky, M. S., Averianov, A. O., Pervushov, E. M., Ratnikov, V. Yu, and Zozyrev, N. Yu., 2008, On ichthyosaur remains from the Cretaceous of the Voronezh region: Paleontological Journal, v. 42, n. 3, p. 287-291.

Van Vranken, Nathan, 2017, Texas Cretaceous Ichthyosaurs: A Glimpse of Their Last Days in the Early Late Cretaceous.

Sunday, February 12, 2017

Bulbasaurus: Beast of the Week

This week we will be looking at a newly described reptilian relative of mammals.  Check out BulbasaurusBulbasaurus was a dicynodont, a wildly successful group of plant-eating reptiles that shared characteristics with mammals.  It lived during the late Permian, between 260 and 252 million years ago, in what is now South Africa.  From beak to tail it would have roughly measured two feet long...maybe a bit less.  (Only the skull has been found, which was about six inches long.)  The genus name, "Bulbasaurus", tranlsates to "bulbous reptile" in reference to the bony mass above its nose.  The species name, "phyloxyron", translates to "leaf razor", in reference to how it may have cut leaves to eat with its beak. 

Life reconstruction of Bulbasaurus, by Christopher DiPiazza.

Bulbasaurus, as stated above, was a dicynodont.  Dicynodonts were interesting reptiles that looked like a combination of a few different animals alive today.  I have heard many compare them to pigs...but I never really saw that.  They had proportionally large heads, and broad beaks.  Many kinds had two tusks protruding downwards from their top jaw.  They would have walked in a squat, semi-sprawling posture on four, stout legs.  So if I were to describe a dicynodond in terms of modern animals...I'd say just imagine a French Bulldog...with beak...yeah...yeah, that's perfect. 

Bulbasaurus was an important find because it was a member of the family within dicynodonts, called geikiidae.  Until its discovery, geikiids were only known from significantly later times in the Permian and Triassic.  Bulbasaurus sets the first geikiids back millions of years than what was previously thought, however.  Geiikid dicynodonts typically had particularly large, robust heads, curved beaks, and longer tusks, which Bulbasaurus had when compared to its contemporary family members. 
 

Bulbasaurus skull from the paper recently published by Christian Kammerer and Roger M. H. Smith.

SO WHAT ABOUT THAT NAME?!  Was Bulbasaurus named after the pokemon, Bulbasaur? It certainly looks similar.  In fact, Bulbasaur, the pokemon's design was almost certainly based off dicynodonts, as I explained in a post last year.  According to interviews with Dr. Christian Kammerer, one of the paleontologists who worked with, and lead author of the paper that describes Bulbasaurus, it's insisted the name is a coincidence, and it really is just in reference to it's nose...and the species name...."leaf razor" in reference to it's beak, despite the fact that any pokemon fan can tell you one of Bulbasaur's signature attacks is called razor leaf.  I guess we will just have to believe them just like you should just believe my illustration of Bulbasaurus in no way is in reference to Bulbasaur, the pokemon's, color scheme, nor is the pose and setting inspired by the artwork on Bulbasaur's first pokemon card...

Stop looking for things that aren't there!  Definitely no connection here.  Total coincidence.

References

Kammerer, C.F.; Smith, R.M.H. (2017). "An early geikiid dicynodont from the Tropidostoma Assemblage Zone (late Permian) of South Africa". PeerJ. 5. doi:10.7717/peerj.2913. ISSN 2167-8359.

Kammerer, C.F.; Angielczyk, K.D.; Frobisch, J. (2011). "A Comprehensive Taxonomic Revision of Dicynodon (Therapsida, Anomodontia) and Its Implications for Dicynodont Phylogeny, Biogeography, and Biostratigraphy". Journal of Vertebrate Paleontology. 31 (sp1): 1–158.