Sunday, July 26, 2015

Styracosaurus: Beast of the Week

This week we will be checking out Styracosaurus, the spike-frilled dinosaur!  Styracosaurus albertensis lived in what is now Alberta, Canada during the Late Cretaceous Period, 75 million years ago.  From beak to tail it measured about eighteen feet long and was a plant-eater.  The genus name, Styracosaurus, translates to "Spike Lizard/Dinosaur" in reference to the eight long spikes growing from the sides of its frill.  When alive, Styracosaurus would have shared its habitat with other dinosaurs like Parasaurolophus, Corythosaurus, and Euoplocephalus.

Styracosaurus engaging in a display standoff.  Reconstruction by Christopher DiPiazza.  Get out of the way, snake!  It's about to GO DOWN!

Styracosaurus is considered a ceratopsian dinosaur (frills, beaks, and horns), in the same family as Triceratops.  More specifically, however, it is considered a centrosaurine ceratopsian, which are characterized by having very deep snouts and shorter frills, relatively speaking.  Other examples centrosaurine ceratopsians are Pachyrhinosaurus and Nasutoceratops.

The most striking feature about Styracosaurus is definitely its frill and horn ornamentation.  It had one straight horn on its snout and around its frill were eight more large horns/spikes on the top (four on each side) and a series of smaller horns, called epoccipitals on the sides.  The most popular idea for the purpose of these horns is for display, but it is possible they were good deterrents against would-be predators too.  Many defensive weapons animals evolve have similar designs to what you see on Styracosaurus's skull, long, straight spears facing outwards, keeping enemies as far away as possible.  Think of animals like hedgehogs, porcupines, and certain kinds of lizards, like Bearded Dragons, or Horned Toads for modern examples of this. The skulls of Styracosaurus and other centrosaurine dinosaurs have been examined closely by scientists and little to no signs of damage from other horns could be found, leading most to believe that they probably weren't fighting each other with them...at least not on the face.

Front view of the Styracosaurus' skull on display at the American Museum of Natural History in New York.

The beak of Styracosaurus was narrow, and the lower beak tip was extremely long and curved upwards.  This would be a good adaptation for clipping specific plants to eat, much like a giant pair of rose trimmers.  Because of this it is likely that Styracosaurus and its relatives were more selective feeders.  Other plant eaters, like Euoplocephalus with its wide beak, seem to have been more generalists, likely sucking up pretty much any plant material that was in front of them.   In the back of Styracosaurus' mouth were hundreds of small teeth packed together, forming what are called dental batteries.  These structures were designed for slicing tough plant material, rather than grinding it, which is what you would see in a duckbill dinosaur's mouth, which also had dental batteries but in a flatter shape.

Side view of the same Styracosaurus specimen as above at the American Museum of Natural History.

There have been bone beds comprised of multiple Styracosaurus skeletons discovered, but it is still unclear as to if they were actually herding animals.  The reason for this is because the area in which the dinosaurs seemed to have died was a riverbed at the time of their death.  Frequently, animals, herding or not, will congregate at water sources like this and drown in flash floods all at once.  Therefore it could be possible Styracosaurus may have still preferred the solitary lifestyle.  It would be difficult to cuddle with those big spikes anyway.

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

References

Eberth, David A.; Getty, Michael A. (2005). "Ceratopsian bonebeds: occurrence, origins, and significance". In Currie, Phillip J., and Koppelhus, Eva. Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Bloomington: Indiana University Press. pp. 501–536.

Lambe, L.M. (1913). "A new genus and species from the Belly River Formation of Alberta". Ottawa Naturalist 27: 109–116.

Ostrom, J. H. (1966). "Functional morphology and evolution of the ceratopsian dinosaurs". Evolution 20 (3): 290–308.

Tait, J.; Brown, B. (1928). "How the Ceratopsia carried and used their head". Transactions of the Royal Society of Canada 22: 13–23.

Tanke, D. H, and Farke, A. A. (2006). Bone resorption, bone lesions, and extracranial fenestrae in ceratopsid dinosaurs: a preliminary assessment. in: Carpenter, K. (ed.). Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs Indiana University Press: Bloomington. pp. 319–347.

Friday, July 24, 2015

National Zookeeper Week: 2015

The third week in July is officially recognized as Zookeeper Week, a week where we are encouraged to recognize and be thankful for the hard work that zookeepers put in every day at their jobs.  As you may or may not know, I have been a zookeeper for two amazing facilities.  The experiences I gained from that line of work, with regards to working with the animals and my coworkers, is priceless and continues to stick with me every day as I go on with my life.  One of these facilities I started working at when I was only thirteen years old, so exotic animals has been a part of my life for a long time.  All this being said, if you like wildlife, it is important that you go out and support zoos every chance you can.

This photo was taken on my last day at the Bergen County Zoo earlier this summer.  The animal I am holding is called a Springhaas or Springhare.  It is a rodent native to Africa that hops on its hind legs like a small kangaroo.  It's one of those animals that few people have heard of and it's a real shame because they really are awesome.
The amount of work that zookeepers put into their jobs is insane.  If you were to go online and look up job openings for zookeepers, you will notice that they all require you to have at least a bachelor's degree in biology, zoology, ecology, or something else related. (Many prefer you have even more academia under your belt.)  Often times in order to get a paying zoo job, you need to start as an intern or volunteer first.  For some reason there is a silly idea that some people believe that a zookeeper is a position you have if you don't do well in life.  I actually overheard a father say to his kids as they watched a keeper clean an enclosure "See kids?  That's what happens when you don't go to college!"  Little did he know that keeper probably has more education (and very likely could have been happier with her job) than him.

I made this a few years ago.  There is actually a bit more to the job than picking up poop...but poop is a big part of it.

You then would notice that the hours are pretty crazy.  Zookeepers need to be at the zoo hours before opening to feed and clean enclosures and hours after closing for the same reasons.  Animals need to be taken care of every day...even Christmas...and New Years...and Thanksgiving...and if the weather is bad and there is six feet of snow outside...or if the streets are covered in ice... or flooded from a hurricane. (All things I have personally worked through, by the way!  I knew it was bad when I had to stop my car and move wooden road blocks out of the way to get to work one morning.)  There is a team of keepers at the zoo every single day.  When I was working, many times visitors would ask me when we close for the season, to which I reply "We are open year round."  They look surprised at me especially when I confirm that we are even open on holidays.  Animals are alive, people!  They need to eat just like you!

Tigger here is a Serval, a cat native to the savannahs Africa.  He was originally obtained (I have no clue how) as a kitten by a man who intended to keep him in his apartment until (shocker) he got too big!  He now lives safely and happily with us at a facility that can meet the needs.  Many animals you see in zoos, have similar stories.  Zoos, in addition to promoting education and conservation, are also sanctuaries for exotic animals that have been rescued from places they should never have been at in the first place.

You might be thinking, "Wow!  No wonder it's so competitive!  Zookeepers must have it made!"  Then scroll down and check out the pay.  Most zookeepers make about minimum wage.  Many work second jobs.  So why do we do it?  Why is it so competitive?  The answer to that is that all zookeepers genuinely care about the animals they work with and love what they do.  Every single one.  Another nasty, false image, which is very common in the minds of people who think zoos are prisons/bad for animals (which I can go into debunking another time) is that of a zookeeper who simply goes through the motions every day and works towards the paycheck at the end of the week.  I will go on record in saying that in my experience, I have never met one zookeeper who fit that description.  We do what we do for the animals, not the money.  I have been very fortunate to have only ever worked at places I genuinely loved.  Like I said, I started in a zoo when I was only thirteen, and only when forward from there.  The way that I can tell I have the right job is when I'm having a bad day, the kind of day when I'm tired and frankly just want to nap/cry, I ask myself in the middle of all that "Is there anyplace else you would rather be right now?"  If the honest answer is "no" then I know I'm in the right place.  I challenge you to do it the next time you are having a bad day at work!

Burmese Python cuddle parties are the best parties.  It can put anyone in a good mood.

So you get that zookeepers work hard, but what do they do they do that benefits everyone else?  Well for starters they allow us to see animals in person that otherwise most of us would only ever see in books or on television.  Think about it, unless you shelled out the money for a special access trip to the jungles of Africa (I know I sure can't afford it), how would you ever see a live Gorilla, let alone up close and safely?  Not only do zookeepers make the animals accessible to you, but they make sure that the animals are entertained too.  It's mindblowing how much research and work goes into keeping the animals healthy, comfortable, and happy at zoos.  Since the animals in zoos don't have to stress over hunting/foraging or finding shelter, we need to make sure their extra time is stimulating in other ways.  Depending on the species, we do this by giving them different toys to play with, introducing smells into their enclosure for them to react to, like safe perfumes, spices, or even fur or feathers from a neighboring zoo tenant! (Our porcupine and mountain lions love to chew on the Elk's shed antlers!)  We also will feed them in ways other than just plopping the food down in front of their faces so they still need to work or use their brains to get meals.  For example, around Christmas time, we feed some of the animals by putting their food in a wrapped cardboard box (we have to meticulously check each one for staples and tape first to make sure they are all safe first, of course.)  The results are stimulating for the animals and fun to watch.  Below are videos I shot of our Mountain Lions and Male Andean Condor engaging in the holiday fun.


Zookeepers also do good for wild animals.  When you visit an AZA accredited (Association of Zoos and Aquariums) zoo and pay admission, part of the money you spend goes towards wildlife conservation and research.  In fact, each AZA zoo is required to do this in order to keep its license as an AZA facility.  The zoo I worked at, for instance, funds research of wild giant armadillos in South America, a mammal that we still don't really know all that much about in the wild!  We were also were able to release an Andean Condor we bred into the wild with a number and tracker.  When she was last seen over the Andes Mountains, flying with a male partner, and may have produced chicks of her own.  How exciting!

Our male Andean Condor.

As you can see now, there is more to being a zookeeper than just shoveling poop and picking up a paycheck.  (Okay, actually there is a lot of poop shoveling.)  We do what we do because the experience is priceless to us.  So go out and visit your nearest zoo!  Learn new things.  Ask questions!  Happy Zookeeper Appreciation Week!  Go out and hug a zookeeper...unless they don't want to be touched...some of them don't like to be touched by strangers...also they might have tapir poop on them or something...not like there is anything wrong with that!...Maybe just say thank you. 
For more information on Zookeeper Week click here!


Wednesday, July 22, 2015

Museum Camp: Kids Interpret Skeletal Mounts

WARNING: The following post contains drawings and interpretations of adorable six-year-old kids who love dinosaurs and may cause your head to explode from utter cuteness overload.  You have been warned.  

As some of you may know, I recently started working at the American Museum of Natural History in New York City.  Part of my job is to interact with kids.  Lots of kids.  So many kids come through those doors every day and more often than not, they want to see dinosaurs.  I actually overheard a little boy say to his parents as he walked in "If I don't see the dinosaurs first I am going to punch everyone in this museum."  ...I can respect that!

During the summer months we have day camps at the museum for various age groups.  Recently we just finished up a week of paleontology-themed camp for six, seven, and eight year olds.  We take them around to the exhibits before the museum opens and challenge them to come up with their own hypotheses about the fossils on display and then we compare them with what the experts believe.  It's a very fulfilling experience that gives the kids a good introduction to what real paleontology is like, which is a lot of saying "we don't really know for sure!"

One exhibit we take them to is probably the most dramatic in the whole museum.  Its of an adult Barosaurus defending her baby from an attacking Allosaurus, by rearing up on her hind legs.  When I was a kid during the 90s, shortly after this mount was erected, I felt like I was going to get a nosebleed looking up at it.  It is really an awesome sight even today as an adult who has been through this entrance countless times.

One of the perks of working here is when I arrive early before the museum opens, I can get the best pictures without the crowds of people with their stupid selfie sticks getting in the way.

We asked the campers to draw or write in their notebooks what they think is going on in the scene.  We don't give them too much instruction.  In the field when you find a new fossil, there are NO instructions as to what it is, where it goes, or what it was for!  All you have is your prior knowledge of the subject, logic, and creativity to guide you!  We also allow the kids to converse with each other if they want since real scientists bounce ideas off each other all the time too.  One little girl created reconstructions of both kinds of dinosaurs that really made my day.  She even added dialogue!  Click on the images to see a larger view!

The Allosaurus was particularly threatening.  Very Bold!

She writes "You are going to die because I am going to KILL YOUR BABY! AAAHHHH!"

But mama Barosaurus isn't taking any of the theropod's crap today.

"Hey you, girl.  Go away from my baby girl! AHHH!"  I like to imagine her snapping her fingers and bobbing her head from side to side as she says this. (Yes I know sauropods didn't have fingers for snapping.  Calm down, fanboys.)

Well I hope that was enough cuteness for one day.  I will be posting a lot more about my time at the museum in posts to come.  Stay tuned!

If this scene ever did take place, that would have been a very brave Allosaurus...or a very stupid one.

Monday, July 20, 2015

Baryonyx: Beast of the Week

This week we shall be checking out a dinosaur that seemed to have been specially adapted for getting its food from the water.  Enter Baryonyx walkeri!

Baryonyx was a meat-eating dinosaur that lived in what is now Southern England, Spain, and Portugal, during the Early Cretaceous Period, between 130 and 125 million years ago.  From snout to tail it measured about thirty one feet long. (Although paleontologists believe an older adult could have grown even larger.)  The genus name, Baryonyx, translates to "Heavy Nail/Claw" in reference to the first claw on each of its hands which were each almost ten inches long!  When alive, it would have coexisted with many other dinosaurs that are known from the area, including Eotyrannus, Mantellisaurus, and Iguanodon, to name just a few.

Baryonyx walkeri life reconstruction by Christopher DiPiazza.

Baryonyx belongs to the family, spinosauridae.  Spinosaurids were theropod dinosaurs which all had long, narrow snouts filled with pointed, cone-shaped teeth.  Spinosaurids also all had three fingers on each hand, with the first claw on each being much bigger than the others.  Even though the much more popular, Spinosaurus, was discovered first (and thus the family name is in its honor), Baryonyx was the first Spinosaurid in which paleontologists were able to identify these telltale morphological characteristics from.  Spinosaurus, on the other hand, was only known from very scant remains and was reconstructed as a general large theropod until relatively recently.  Since the discovery of Baryonyx in the 1980s, several more kinds spinosaurids have also been discovered.

Baryonyx skeletal mount on display at the London Museum of Natural History.

So what was the reason Baryonyx evolved such an interesting snout?  It is unlike most snouts seen on other large kinds of theropods, which tend to be much deeper.  The answer lies in the stomach contents of Baryonyx, which luckily, also fossilized!  Paleontologists were able to identify fossilized fish scales and bones inside where the stomach of Baryonyx once was.  This confirms that Baryonyx had a taste for seafood! (or riverfood...um...swampfood?)  This makes sense given the long snout and the pointed teeth, which would have been ideal for snapping up and holding onto slippery aquatic prey.  Baryonyx's nostrils were also placed about midway up the snout, not at the tip, like in most theropods.  This would make sense if it was dipping its face in the water frequently.  The giant, hook-shaped claws of this dinosaur also may have played a role in fishing as well, by being able to grab anything that somehow managed to escape the jaws.  Also keep in mind that what is now Southern England, was once a vast network of swampy rivers and lakes during the Early Cretaceous, when Baryonyx lived there, where it would have had no problem finding plenty of fish to eat.  I can imagine Baryonyx when it was alive hunting in a humid Cretaceous wetland with the front of its snout submerged in shallow water, slightly ajar, as it stands motionless, waiting for prey to venture close enough.  It would stand still for so long that local fish would start to get used to the large dinosaur as just another part of their environment.  Then, when the time was right it would snap up an unlucky fish lightning fast, tossing its head back and swallowing it whole!

Baryonyx's digit 1 claw.

Baryonyx wasn't just a fish-eater, however.  There have also been chunks of Iguanodon bones found inside of it's skeleton, as well, proving that other dinosaurs weren't off the menu for this spinosaurid, either.  Whether or not Baryonyx killed the plant-eating dinosaurs itself, or scavenged them is still a mystery.  Baryonyx's jaws, although relatively narrow, were still more robust, and capable of sustaining more pressure than those of other, more specialized members of its family, like Spinosaurus.

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

References

Charig, A. J.; Milner, A. C. (1997). "Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey". Bulletin of the Natural History Museum of London 53: 11–70.

Cuff, A. R.; Rayfield, E. J. (2013). Farke, Andrew A, ed. "Feeding Mechanics in Spinosaurid Theropods and Extant Crocodilians". PLoS ONE 8 (5): e65295.

Edwards, D. D. (1986). "Fossil Claw Unearths a New Family Tree". Science News 130 (23): 356. doi:10.2307/3970849. JSTOR 3970849.



Sunday, July 12, 2015

Edestus: Beast of the Week

As this year's shark week comes to a close, let's take a look at an ancient fish that makes even the modern Great White look relatively mundane.  Check out Edestus!  Most people are aware that sharks have been around since prehistoric times, even before the first dinosaurs, but many don't realize how different some of these fish looked from any that are alive today. 

Edestus was a genus of of prehistoric cartilaginous fish (fish with a skeleton mostly made of cartilage, like rays, ratfish, and sharks) that lived during the late Carboniferous Peridd, about 300 million years ago in oceans around the world.  The genus, Edestus, includes several species, the largest of which, called Edestus giganteus, is estimated to have been about twenty feet long from snout to tail when alive.  The genus name, Edestus, translates to "Devourer" because the teeth...well, you'll see why.

Edestus heinrichi life reconstruction by Christopher DiPiazza.  Since only the jaws are known, the body I used references from modern sharks, and chimera fish.  The real living animal may have looked different from this.

Edestus had some of the most unique jaws of any vertebrate, let alone fish.  Unlike most sharks, which constantly replace their teeth during their lives as they fall out for various reasons, Edestus held on to its teeth, but also added teeth as it grew.  As this happened the upper and lower jaws of Edestus were gradually growing and curving outwards as the animal aged, making room for new teeth.  This resulted in a profile that looks a lot like when you stick two Pringles chips in your mouth and pretend to be a duck.  (If you ever ate Pringles in your life, you have done this.)

"Look at me!  I'm an Edestus!"

The teeth themselves varied a bit from species to species of Edestus, but they all appear to have been meant for eating meat.  Another interesting thing about the teeth is the fact that they were symmetrical, so one side wasn't more flat than the other.  This means that Edestus' mouth consisted of a single row of teeth, which were parallel to the body, rather than perpendicular like in other animals.  Think of it sort of like having a pair of scissors sticking out of the front of the face.

Photograph of three different species of Edestus teeth from Itano's 2014 paper.  The species pictured from top to bottom are E. heinrichi, E. minor, and E. newtoni.

So what kind of feeding strategy did Edestus employ with this truly unique mouth?  One idea is that it would have swam through its prey, essentially cutting it in half as it did so, and then swallowed the pieces after.  Another idea is that it was adapted for cracking open prey with tough shells on the outside, like marine arthropods.  Some believe it was a jellyfish eater. 

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

References

Itano, W. 2015. An abraded tooth of Edestus (Chondrichthyes, Eugeneodontiformes): Evidence for a unique mode of predation. Transactions of the Kansas Academy of Science. 118 (1-2): 1-9

Itano, W. 2014. Edestus, the strangest shark? First report from New Mexico, North American Paleobiogeography, and a new hypothesis on its method of predation. The Mountain Geologist. 51 (3): 201-221

Sunday, July 5, 2015

Masiakasaurus: Beast of the Week

This week we shall be looking at an awesome little dinosaur with teeth unlike any other!  Check out Masiakasaurus knopfleriMasiakasaurus was a meat-eating (probably) dinosaur that lived in what is now Madagascar during the late Cretaceous, about 70 million years ago.  From snout to tail, an adult would have measured roughly between six and seven feet long.  The genus name, Masiakasaurus, translates to "Vicious lizard/reptile" and the species name, knopfleri, is in honor of singer/songwriter/guitarist, Mark Knopfler, who's music the paleontologists who found this dinosaur's fossils were listening to during their time in the field.

Masiakasaurus life reconstruction by Christopher DiPiazza.

Masiakasaurus belonged to the family of dinosaurs called noasauridae.  Noasaurids, were generally smaller theropods that lived in the southern hemisphere during the Cretaceous.  They are a branch of the broader group of theropods, called ceratosaurs, which also includes the larger, more well known, Ceratosaurus and Carnotaurus, to name just a few.

The most prominent feature about Masiakasaurus, however, is definitely its teeth and jaws.  Unlike the teeth of most other theropods, which angle perpendicular to the jaw, the teeth of Masiakasaurus were angled forward int he front of the mouth.  This striking appearance was what earned its name as "vicious".  Despite its appearance, however, was Masiakasaurus really all that dangerous?  Probably not unless you were a small mammal or an insect.  Having teeth pointing forward would have made it difficult for Masiakasaurus to have dealt much damage to any animal close to its size or larger.  However, its teeth do make a great adaptation for grasping small, fast moving prey, like a moveable cage.  The environment Masiakasaurus lived in did have many small animals in it at the time, thanks to a great fossil record from Cretaceous Madagascar, including frogs, mammals, small crocodilians, and even small birdlike dinosaurs.  Another idea that some people have proposed is that Masiakasaurus was a fisher.  In fact, we see similar, unrelated examples of teeth like this in many marine reptiles, like Plesiosaurus, which paleontologists are almost positive was a fish-eater in life.  The teeth in the back of Masiakasaurus' mouth were more similar to those of other theropods, and would have been for cutting food to be swallowed. 

Masiakasaurus skull, featuring the unique teeth and jaws.  CLEARLY it lived during a time before orthodontists.

In addition to its teeth, some other notable features about Masiakasaurus would be its neck, which was long and actually not very flexible, which is not the norm compared to other kinds of long-necked theropods.  Its hands each had four fingers, but only the first three digits on each had claws.

Masiakasaurus skeleton on display at the Royal Ontario Museum in Toronto, Canada.

Masiakasaurus is a great find by paleontology standards because it is known from more than one specimen, so almost all of its anatomy is known.  Another interesting thing about Masiakasaurus, is that paleontologists were able to study what they think was its growth pattern based on individual specimens of different sizes that have been found.  Based on what the pool of specimens available to work with and by closely examining the kind of bones Masiakasaurus had compared to those of other dinosaurs, it is hypothesized that Masiakasaurus was actually a relatively slow-grower, and would have attained adult size by the time it was about eight years old.  This is indeed pretty slow compared to other non-avian dinosaurs that have been studied in the same way and even modern animals that are related to it, like birds, which reach adulthood, in general, much more rapidly.  (Anyone who has ever raised a baby chick knows exactly what I'm talking about.  Seriously, one minute they are fluffy yellow peeps... blink once and BAM...adult chicken.)

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

References

Carrano, M.T.; Sampson, S.D.; Forster, C.A. (2002). "The osteology of Masiakasaurus knopfleri, a small abelisauroid (Dinosauria: Theropoda) from the Late Cretaceous of Madagascar". Journal of Vertebrate Paleontology 22 (3): 510–534.

Carrano, M.T.; Loewen, M.A.; Sertic, J.J.W. (2011). "New materials of Masiakasaurus knopfleri Sampson, Carrano, and Forster, 2001, and implications for the morphology of the Noasauridae (Theropoda: Ceratosauria)". Smithsonian Contributions to Paleobiology 95: 53pp.

Andrew H. Lee & Patrick M. O’Connor (2013) Bone histology confirms determinate growth and small body size in the noasaurid theropod Masiakasaurus knopfleri. Journal of Vertebrate Paleontology 33(4): 865-876.