Thursday, February 28, 2019

Protoceratops: Beast of the Week

This week we will be looking at a well known ceratopsian dinosaur.  Say hello to Protoceratops!  This little dinosaur measured about six feet long when fully grown and lived in what is now Monglolia during the Late Cretaceous, roughly 80 to 75 million years ago.  Like all ceratopsians, Protoceratops was likely a plant-eater.  The genus name, Protoceratops, literally translates to "first horned face".  Nowadays we know that Protoceratops was far from the earliest of the ceratopsians but at the time of its discovery back in the 1920s it was the oldest known.  The discovery of Protoceratops also proved to scientists that the ceratopsian family line originated in Asia, not North America, where its later-living relative, Triceratops, was unearthed.

Life reconstruction of two Protoceratops by Christopher DiPiazza.  There are variations in the skull shapes among the many Protoceratops on the fossil record.

Protoceratops, like many of its relatives had a broad frill growing from the back of its skull, made lighter by two large holes, called finestra.  It had a hooked beak, which would have been backed up by extremely powerful jaw muscles, which enabled this dinosaur to eat the tough, and possible thorny vegetation that lived in its arid habitat.  It had proportionally long legs for a ceratopsian, and its tail that was flattened laterally by elongated neural arches.

Protoceratops skeletons on display at the American Museum of Natural History in New York.

Protoceratops
 is a great dinosaur to study because there are just so many specimens on the fossil record.  Scientists have found tiny babies, fully grown adults, and many life stages in between.  There is even a three-dimensional articulated skeleton on display at the Museum of Natural History in New York.  Because there are so many individuals of Protoceratops on the fossil record, scientists were noticed that even among adult-sized animals, there was variation in their skull shapes.  Some individuals had wide, frills and extremely tall snouts, while others had more narrow snouts and proportionally smaller frills.  Some have suggested this is an example of sexual dimorphism, the larger-headed individuals being males, and the more narrow-headed ones, the females.  Others have countered that this also may be simply a difference in maturity even after the animal's overall body size has reached adulthood.

Protoceratops skulls on display at the American Museum of Natural History, showing small babies leading up to mature adults.

Protoceratops was likely a tough little dinosaur.  It had to be since its habitat would have been an arid desert.  Protoceratops' small size in this environment is no coincidence since desert animals tend to evolve smaller.  The smaller your body is, the less food and water you require to stay alive, and the easier it is to get shelter.

An often overlooked, but impressive specimen of a Protoceratops preserved in the pose it died in, likely due to a sandstorm, io display at the American Museum of Natural History in New York.

A crushed Oviraptor skull was discovered nearby what were originally believed to be Protoceratops eggs.  Scientists thought that the ceratopsian defended its brood by pulverizing the poor theropod's head.  As it turns out, the eggs actually belonged to Oviraptor, not Protoceratops.  Since that discovery, however, paleontologists have found young Protoceratops in nests of their own, as well.  This suggests that Protoceratops, like many other dinosaurs, cared for its young for a time after they hatched. 

Famous fossil that shows what appears to be a Protoceratops and Velociraptor fighting.

An even more spectacular fossil was found during the early 70s of a Protoceratops with a Velociraptor's arm clamped in its beak.  It appears that the Velociraptor's toe claw was embedded in the ceratopsian's neck and that the two were locked in dramatic mortal combat when they perished in a sandstorm.  Whether or not this is actually how they died is truly uncertain.  One thing that is for sure, however, is that these two dinosaurs were practically on top of each other when they died and I'm pretty confident it wasn't to cuddle.  One of the reasons why I love Protoceratops so much is because despite it having been a plant-eater (and a relatively small one at that), it actually proves to have probably been a force to be respected by other dinosaurs when it was alive.  Plant-eaters always get this "gentle" label which is just plain false.  Just take a look at animals today like Buffalo and Hippos, which can be extremely aggressive, to see what I mean.  Extinct dinosaurs, like little Protoceratops, could have been much the same.

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

References

Carpenter, Ken. (1998). "Evidence of predatory behavior by theropod dinosaurs.". Gaia 15: 135–144. [not printed until 2000]

Choi, Charles. "15 Infant Dinosaurs Discovered Crowded in Nest". LiveScience.com. November 17, 2011.

Maiorino, Leonardo, et al. “Males Resemble Females: Re-Evaluating Sexual Dimorphism in Protoceratops Andrewsi (Neoceratopsia, Protoceratopsidae).” Plos One, vol. 10, no. 5, 2015, doi:10.1371/journal.pone.0126464.

"Protoceratops." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. The Age of Dinosaurs. Publications International, LTD. p. 118-119. ISBN 0-7853-0443-6.

Dodson, P. (1996). The Horned Dinosaurs. Princeton University Press, Princeton, New Jersey. pp. 200–234. ISBN 0-691-05900-4.

 Mayor, A. (2000). The First Fossil Hunters: Paleontology in Greek and Roman Times. Princeton University Press, Princeton, New Jersey. ISBN 0-691-05863-6.


Sunday, February 24, 2019

Academy of Natural Sciences: Tiny Titans

The Academy of Natural Sciences recently had a seasonal exhibit showcasing dinosaur babies and eggs, called "Tiny Titans".  I was fortunate enough to be able to walk through it a few times and take photographs.

I was pleasantly surprised to see that this exhibit has a lot of full skeletal mounts of dinosaurs, often posed with young or on nests.  The first one you meet when you come in is of the small ceratopsian, Protoceratops flanked by several youngsters.  Protoceratops was almost always depicted as guarding a nest of eggs in popular media and art.  Ironically, the eggs that we thought belonged to it actually came from a different dinosaur, Oviraptor.  Since then, however, we have found actual Protoceratops eggs and babies as well.

Protoceratops skeletal mount with babies.

Speaking of nests and Oviraptor, what kind of eggs and babies exhibit would this be without oviraptorosaurs?  The exhibit sports a beautiful life-sized cast of a fossil nest from what was a some king of oviraptorosaur, judging by the shape of the eggs (long, narrow) and their placement.  We know this kind of dinosaur laid eggs in pairs, and in a ring pattern so the parent could safely sit in the middle and cover them with its arms.

Nest of giant oviraptorosaur eggs.  My hand for scale.

There is also a great skeletal mount of Conchoraptor, in a brooding position.  It was exciting to see an oviraptorid that wasn't Citipati showcasing this for a change.

Concoraptor on a nest of eggs.

One thing that really excited me was the sculpture of the dinosaur embryo that was on the cover of National Geographic Magazine in 1996.  This was based on a dinosaur embryo that was nicknamed "Baby Louie".  We now know this embryo was a kind of oviraptorosaur, recently named Beibeilong.

Baby Louie!  If this model was made now he'd have a beak, since we know he was an oviraptorosaur.

There was a case showcasing a dinosaur egg (from as sauropod judging by how perfectly round it was) that had turned into a geode.  Silica had gotten inside the egg through the porous shell during the fossilization process and formed beautiful crystals on the inside.  I had no idea that could happen to a dinosaur egg.  It was neat to see.

That dinosaur egg geode was incredible.

Another really cool feature about this exhibit was a station where the visitor could look at fossilized embryonic titanosaur skin under a powerful magnifier.  I love a good sample of fossil dinosaur skin.  They are so rare ans so precious, especially for paleoartists!

Close up view of embryonic dinosaur skin.

This exhibit also featured several skeletons of the small ceratopsian, Psittacosaurus, which is known from many individuals on the fossil record, including babies.  There was a cast on the wall of what appeared to be an adult Psittacosaurus that had its body wrapped around thirty four baby Psittacosaurus.  All the skulls of the babies were above their bodies, which shows that they died very fast and they fossilized in their life poses.  Unfortunately it was found out in 2013 that the adult's skull was never a part of this fossil, and was glued on to make it more dramatic.  Also it was found out that the skull of the adult was from an individual that was too young to have had babies of its own when it died, so it couldn't have been the parent anyway.  That being said, this fossil is still proof that baby Psittacosaurus were at least gregarious in life, which is an exciting all on its own.

Dramatic fossil of thirty four baby Psittacosaurus that died together quickly in was could have been a burrow collapse.  The adult skull was not found with them.

The last part of the exhibit has a stretch of life-sized images of famous dinosaurs, including Diplodocus, Maiasaura, Triceratops, Stegosaurus, and Tyrannosaurus, by paleoartist, Luis Rey.  In front of each of these dinosaur images was a small fence-like pen, with a roughly three to four foot model of  that dinosaur's "baby".  I could see they were going for a dinosaur petting zoo kind of vibe.  This part had potential to be really cool, since we actually do know a lot about the babies of those particular dinosaurs.  It would have been a great opportunity to show the proportional differences between babies and adults and how they would have changed as they aged.  Unfortunately that is not what was offered.  These "babies" were more or less poorly done, shrunken versions of the adults.

The Luis Rey art is beautiful.  If only the models would match.

The Triceratops looked like it was kind of trying, since its horns were shorter, but it still didn't match what we know baby Triceratops looked like.  The Maiasaura looked more like a hypsilophodontid than anything else.  The "baby" Tyrannosaurus was the most offensive.  I think it was modeled after the Tyrannosaurus toy from the company, CollectA, which isn't even an accurate representation of an adult Tyrannosaurus, let alone a baby, which we know would have looked very different, with longer legs and an overall lighter build.  The kids in the exhibit seemed to be loving it, however, and it was a great opportunity for selfies...it was just a missed opportunity to educate without taking anything away from the fun.

The adult T.rex is wondering why her baby is so ugly.

Overall this was a cool exhibit.  It was a neat contrast to see so many tiny baby skeletons and eggs after looking up at the massive adult skeletons in the museum's main fossil hall.  There was also a lot of interactive and truly educational content for any age of visitor.  Unfortunately, Tiny Titans is no longer at the Academy of Natural Sciences, but it could pop up at another museum soon!

References

Pu, Hanyong, et al. “Perinate and Eggs of a Giant Caenagnathid Dinosaur from the Late Cretaceous of Central China.” Nature Communications, vol. 8, 2017, p. 14952., doi:10.1038/ncomms14952.

Zhao, Q. (2013). "Juvenile-only clusters and behaviour of the Early Cretaceous dinosaur Psittacosaurus". Acta Palaeontologica Polonica.








Tuesday, February 12, 2019

Bajadasaurus: Beast of the Week

This week we will be looking at a newly discovered dinosaur that looks right at home in a Tim Burton movie.  Enter Bajadasaurus pronuspinax!

Bajadasaurus was a plant-eating dinosaur that lived in what is now Argentina during the early Cretaceous period, about 140 million years ago.  From snout to tail it would have measured roughly thirty feet long, but this is based on only the few bones of this dinosaur that were actually found.  The genus name translates to "Bahada reptile" in reference to the region in Argentina where its bones were found.  The species name, pronuspinax, translates to "forward-leaning spine" in reference to the spines that grew from its neck.

Life reconstruction of Bajadasaurus in watercolors by Christopher DiPiazza.

Bajadasaurus was a member of the sauropod order of dinosaurs, the well-recognized dinosaurs with small heads, long necks, large bodies, and long tails.  Within that group, Bajadasaurus was a member of the dicraeosaurid family.  Dicraeosaurids were sauropods that flourished mostly in the late Jurassic to early Cretaceous and were relatively small compared to other sauropods.  (if you consider thirty feet small) Dicraeosaurids also tended to have, relatively speaking, shorter necks when compared to those of other sauropods.  Their most diagnostic characteristic is elongated neural arches of some kind. (A neural arch is the top part of a vertebra.  If you run your finger down the back of your neck or your own spine you can feel them in the form of little bumps.)

Skeletal mount of Bajadasurus' skull and neck on display in Buenos Aires.

Elongated neural arches are not rare in the dinosaur world.  Meat eaters, like Spinosaurus and Acrocanthosaurus had them.  The dicraeosaurid sauropod, Amargasaurus, had long, backward-pointing ones on its neck.  Bajadasaurus, however, had extended neural arches unlike any other dinosaur that we know of so far.  Similar to Amargasaurus, it had long, spike-like extensions growing from its neck bones, but they curved forwards, towards the front of the animal, instead of its tail.  The exact evolutionary reason for this is a mystery.  Some suggest this was defense against predators, presenting a wall of pointy things whenever the dinosaur bent its head down to eat low-growing plants or to drink.  Some say they were for display within the species.

Known bones from Bajadasaurus.  Note the single vertebra with the two spines.  Also note the majority of the skull, including teeth.  Image from the most recent paper, published in 2019.


All this being said, it is important to keep in mind that only one neck vertebra of Bajadasaurus has been found so far, sporting two of these long spikes.  Looking at close relatives, like Amargasaurus, the most logical thing to do is assume it had similar structures on the rest of its neck, but as of now we can't know for sure, let alone the exact lengths and shapes of these other spikes, if there were any.  On the flip side, we do have a lot of Bajadasaurus' skull, including its teeth and eye sockets, which is pretty awesome considering sauropod skulls are notoriously the most rarely found parts.  The eye sockets were relatively large and almost perfectly circular, suggesting this dinosaur had decent vision.  The teeth, like those of most sauropods, were concentrated to the front of the mouth, and were shaped like skinny little pegs, ideal for raking vegetation into the mouth to be swallowed.

References

 PA Gallina, S. ApesteguĂ­a, JI Canale and A. Haluza, A new long-spined dinosaur from Patagonia sheds light on sauropod defense system , in Scientific Reports , vol. 9, 2019, p. 1392

Wednesday, February 6, 2019

Prehistoric Beast at the Academy of Natural Sciences: Part 2

Last time I gave you a taste of the Academy of Natural Sciences' main fossil hall.  If you missed it, check it out here.  Today, we will take a look behind the scenes at some of the fossils that most visitors to the museum don't get to see.

Remember, most natural history museums aren't just for the entertainment of the public, they are also working research facilities, so the exhibits you see on display are usually just a tiny fraction of what that museum actually has to offer.  A big reason why so many specimens are kept away from the public is because, especially in the case of fossils, they are safer that way.  Being in a dark, cool, drawer is a lot less taxing then mounted out in the open air under bright lights all day.  There is also protection against the off chance that a visitor might break the rules and try to touch, climb on, or even steal the specimen. (Which happens more often than you might think.)  Because of this many of the skeletons on display are cast replicas, with the real specimens locked away safely elsewhere. 

The second reason why so many specimens are kept behind the scenes is that it's much easier for scientists to work with them, like taking measurements or scanning, that way.  If a fossil is on display, mounted up, or in a glass case, it is a hassle to get it safely out and into a lab for study, then put it back safely after.

As stated in my last article at the Academy, since it is so incredibly old for a museum, some of the specimens kept here have a very deep and rich history.  The Academy of Natural Sciences actually has a valuable collection of ice age mammal fossils. (unfortunately there aren't many mammal fossils actually on display to the public.)  The first of which was shown to me was a Mastodon tooth that originally belonged to former United States president and founding father, Thomas Jefferson.

Mastodon teeth that once were part of Thomas Jefferson's collection.  Note how worn down the one on the left, being held by Jason Poole, is.

One of these teeth was worn down and was actually concave by the time the animal died.  This tells us the Mastodon it belonged to was old when it died.  Jefferson was fascinated by Mastodon, and was hoping there might still be some alive in the still unexplored by Europeans, Western part of the United States.

Jason Poole showing us the Academy's MASSIVE Bison latifrons skull.  Look at the size of that horn core!  Not imagine if it wasn't broken and had a layer of keratin over it!

Elsewhere in the fossil drawers were America's first two scientifically described non-avian dinosaurs.  The museum has casts of both of them on display for guests to enjoy, but it also has the original real specimens!  New Jersey's official state fossil, Hadrosaurus foulkii and New Jersey's resident tyrannosauroid, Dryptosaurus aquiluguis.  In addition to the classic dinosaurs all kids know, like Tyrannosaurus and Triceratops, Dryptosaurus and Hadrosaurus have always been two of my absolute favorite dinosaurs since I was little.  Knowing they existed near where I grew up made me proud to be from New Jersey, and seeing them for real and in person (their bones at least.) was a dream come true.

The real bones of Hadrosauris foulkii.  This was the start of American dinosaur paleontology back in the 1800s.
That's my starstruck face posing next to the real fossils of my favorite meat-eating dinosaur, Dryptosaurus.
Another view of Dryptosaurus' bones.  Jason Poole is holding up the dinosaur's famous giant hooked hand claw. 

The Academy is also home to some more recently discovered dinosaur fossils.  Scientists in association with this museum were responsible for discovering and describing the Jurassic sauropod dinosaur, Suuwassea in the early 2000s.  Some of the original bones of this fascinating beast are on display, but most of the material is safely locked down below.

Original vertebra from the sauropod dinosaur, Suuwassea, being held up by Jason Poole.

Special thank you to Jason Poole who took us down into the depths of the museum's collection to show us all these invaluable fossils.

Our trip through the Academy of Natural Sciences isn't over yet!  Join me next time for a tour through one of the museum's seasonal exhibits about dinosaurs that isn't open anymore!

Sunday, February 3, 2019

Eretmorhipis: Beast of the Week

This week we will be looking at an unusual reptile that swam in the oceans during the Triassic.  Let's check out Eretmorhipis corroldongi!

Eretmorhipis lived in what is now China, during the early Triassic Period, about 250 million years ago.  It measured a little over two feet long from snout to tail and was probably a predator of small marine animals.  The genus name translates to "oar fan" in reference to its wide, flat flippers.  Eretmorhipis was a member of the hupehsuchian order of reptiles, which flourished during the early Triassic and were related to the more well known ichthyosaurs.

Watercolor life reconstruction of Eretmorhipis by Christopher DiPiazza.

Eretmorhipis had a long, tube-like body that was reinforced with thick overlapping ribs and extensive gastralia (belly ribs).  Its front limbs were modified into proportionally huge, wide flippers.  Its back limbs were also flippers but were a little smaller in comparison.  These paddle-like limbs no doubt helped Eretmorhipis propel itself through the water with the help of its tail, which would have also been powerful in life.  Eretmorhipis also had ten bony plates, called osteoderms, in a line down its back.  These may have helped it protect itself from predators, or perhaps were used in some sort of combat within the species.  They also may have helped regulate body temperature, by acting like solar panels to absorb more heat from the sun. Modern reptiles, like crocodilians and turtles, have been known to use their bony armor for all these purposes.

Photo of the latest uncovered specimen of Eretmorhipis, which preserved the skull, showcasing the unusual bill-like snout.

Eretmorhipis' head was proportionally tiny compared to the rest of its body.  Furthermore, it had proportionally tiny eyes compared to the rest of the head!  It also had a long flattened bill-like mouth that squared off at the tip, very similar to that of modern platypus.  Platypus also have tiny eyes, and therefore poor eyesight.  Even though the platypus is not closely related to Eretmorhipis, it may give us clues to help determine how the prehistoric reptile may have hunted.  If it was similar to the platypus, it may have relied on other senses, instead of sight, and sifted around in the mud and sand underwater with its bill to look for small aquatic prey, possibly invertebrates, to snap up and eat.

References

Xiao-hong Chen; Ryosuke Motani; Long Cheng; Da-yong Jiang; Olivier Rieppel (May 27, 2015). "A New Specimen of Carroll's Mystery Hupehsuchian from the Lower Triassic of China"PLoS ONE10 (5): e0126024. 

Long Cheng, Ryosuke Motani, Da-yong Jiang, Chun-bo Yan, Andrea Tintori, Olivier Rieppel. Early Triassic marine reptile representing the oldest record of unusually small eyes in reptiles indicating non-visual prey detectionScientific Reports, 2019