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!

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.

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.

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

Velociraptor: Beast of the Week

Jurassic World Came out this past weekend!  In its honor we will be reviewing a dinosaur that has been requested over and over again but I insisted on holding off on especially when I knew Jurassic Park was going to get a fourth movie installment.  I vowed to wait until the week of its release to finally do it.  This is a dinosaur which became one of the most popular ever right next to Tyrannosaurus, thanks to the Jurassic Park franchise alone.  Despite this, this dinosaur is extremely misunderstood by most people because of Jurassic Park's inaccurate portrayal of it at the exact same time.  Let's get to know Velociraptor!

Velociraptor mongoliensis family getting ready to sleep at dawn.  Painting by Christopher DiPiazza.

Velociraptor is actually known from a few species, but the most well known is called Velociaptor mongoliensis.  The genus name, Velociraptor, translates to "Swift Thief" and the species name is in reference to Mongolia, where the dinosaur's fossils were originally discovered.  Velociraptor lived during the late Cretaceous Period, between 80 and 71 million years ago.  It was a meat-eater, and measured only a little over six feet long from snout to tail.

The environment that Velociraptor lived in during the late Cretaceous would have been a desert, with hot days, cold nights, and little water nor food for animals.  For these reasons, desert animals had to have some sort of evolutionary strategy that would allow them to survive, especially when it came to finding food.  In the case of Velociraptor, paleontologists can tell that it would have had good vision under low light conditions, and likely was active either ad dusk or at night, thanks to the size of its eye sockets and width of its sclerotic rings   Sclerotic Rings are thin, ring-shaped bones that are in the eyes of certain animals, including dinosaurs, that are used to support the eyes.  The size and shape of these rings, when compared to those of animals today and what we know about their lifestyles, helps scientists guess how extinct dinosaurs would have been able to see in different lights.  This would have helped it for a number of reasons.  First of all, the temperatures aren't sweltering at night in the desert.  In fact, deserts at night get quite cool.  This means it would have been more comfortable for Velociraptor to have been active during these times.  Second, some of the prey Velociraptor could have hunted may not have been as active at night, making it easier for the little predator to ambush.  Owls, today frequently attack other birds (including large hawks!) in their sleep using this strategy.

Velociraptor mongoliensis skull on display at the American Museum of Natural History in New York.  It was an expedition by the AMNH during the 1920s, in fact, that yielded the first ever found remains of Velociraptor.

In addition to good vision, Velociraptor had other adaptations that would have helped it hunt.  Its snout was extremely long and narrow, and was filled with blade-like, serrated teeth for slicing meat.  Its hands were each equipped with three long fingers, each tipped with a hooked claw, and its feet, like all members of its family, called dromaeosauridae, were each equipped with a retractable, crescent-shaped claw, on the second toe, for holding struggling prey in place.  The tail of Veloceraptor was stiffened by bony rods inside it, called ossified tendons, and would have enabled it to have made sharper turns while running.

Velociraptor skeleton on display at the Wyoming Dinosaur Center.

Contrary to what you may see in popular media, Velociraptor was covered in feathers in life, just like a bird.  Despite the fact that no actual feathers have been found attached to Velociraptor bones, themselves, (Feathers would have rotted away somewhere within the last 70 million years of the dinosaur being dead.) we do have strong evidence that they were there.  A specimen of Velociraptor that was published in 2007 shows small, evenly spaced bumps on the dinosaur's, ulna. (forearm bone)  The bumps, called quill knobs, are exactly the same as those found on the arm/wing bones of modern birds, which are the attachment sites for large primary(wing) feathers.  Also, many specimens of dinosaurs closely related to Velociraptor that died in more favorable conditions for soft tissue preservation, do have feathers completely preserved right there in the fossil.  Thanks to phylogenetic bracketing, it is safe to say that Velociraptor was definitely a feathered animal.

Arrows pointing to quill knobs on a Velociraptor ulna.

So why did Velociraptor have feathers, especially since it would have been too heavy to fly?  Well, remember I said before it was likely active at night, when it is actually pretty cold in the desert.  Feathers would have helped Velociraptor maintain a warm body temperature during those times.  Today many nocturnal desert animals also have thick fur or feathers for insulation.  Another reason for feathers could have been to help Velociraptor protect its eggs.  We know that other theropod dinosaurs, like Citipati, used their arm feathers to protect their eggs from the elements, so Velociraptor could have been the same.

The Fennec Fox, native to deserts of Northern Africa, has a thick coat of fur to help keep it warm since it is most active at night, when temperatures in its habitat can drop quite low.  Velociraptor may have had feathers for the same reason in it's desert habitat.

Velociraptor was no doubt a predator when it was alive, but it probably wasn't as ruthless and terrifying (at least to a human) as popular media makes it out to have been.  There is no evidence that suggests Velociraptor hunted in packs.  (There is evidence for it in its larger relative, Deinonychus, however.) It is likely Velociraptor was good at hunting small prey, using its wicked retractable talon on each of its second toes to pin down prey so it could rip off pieces of meat with jaws.  There is evidence that Velociraptor scavenged a lot of its meals too, like most meat-eaters will when given the chance, thanks to Velociraptor teeth marks found on the bones of Protoceratops, and even a large pterosaur.

There is one spectacular fossil that shows us that at least sometimes Velociraptor did have run-ins with large prey.  This fossil consists of a Protoceratops and Velociraptor together as they were most likely both killed by a sandstorm and buried immediately.  The Velociraptor's foot, appears to be extended in the neck region of the Protoceratops.  In turn, the Velociraptor's hand is firmly clamped in the ceratopsian's powerful beak.  It is unlikely Velociraptor would have regularly attacked such a much-larger, and potentially dangerous animal, as Protoceratops.  It is most likely that the plant-eater was sick or injured, and/or possibly even the Velociraptor was starving and desperate.  The desert is a harsh place to live and starvation was probably an ever looming possibility for many animals.  Other dinosaurs, in addition to Protoceratops, the ceratopsian, that would have shared this unforgiving habitat with Veloceraptor were the theropods, Oviraptor and Citipati. 

Dramatic "fighting dinosaurs" fossil featuring Protoceratops biting the hand of Velociraptor.

That is all for this week!  Hope you enjoyed getting to know the real Velociraptor!  Please comment below or on our facebook page!

References

Barsbold, Rinchen; Osmólska, Halszka (1999). "The skull of Velociraptor (Theropoda) from the Late Cretaceous of Mongolia". Acta Palaeontologica Polonica 44 (2): 189–219.

Carpenter, Kenneth (1998). "Evidence of predatory behavior by theropod dinosaurs" (PDF). Gaia 15: 135–144.

Hone, David; Choiniere, Jonah; Sullivan, Corwin; Xu, Xing; Pittman, Michael; Tan, Qingwei (2010). "New evidence for a trophic relationship between the dinosaurs Velociraptor and Protoceratops". Palaeogeography, Palaeoclimatology, Palaeoecology 291 (3–4): 488–492

Hone, D.; Tsuihiji, T.; Watabe, M.; Tsogtbaatr, K. (2012). "Pterosaurs as a food source for small dromaeosaurs". Palaeogeography, Palaeoclimatology, Palaeoecology. 331-332: 27.

Motani, R., & Schmitz, L. (2011). Phylogenetic Versus Functional Signals in the Evolution of Form-Function Relationships in Terrestrial Vision Evolution

Osborn, Henry F. (1924a). "Three new Theropoda, Protoceratops zone, central Mongolia". American Museum Novitates 144: 1–12.

Schmitz, L.; Motani, R. (2011). "Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology". Science 332 (6030): 705–8.

Turner, A.H.; Makovicky, P.J.; Norell, M.A. (2007). "Feather quill knobs in the dinosaur Velociraptor". Science 317 (5845): 1721.

Dimetrodon: Beast of the Week

This week we have a creature that is no doubt very popular even in popular culture, but is sadly very poorly understood by the majority of people out there.  Let's get to know Dimetrodon!

Dimetrodon was a synapsid (same wide group that includes us, mammals) that lived during the early Permian Period, between 295 and 272 million years ago (Several species of Dimetrodon spanned this time range.) in what is now the Southwest United States, in Texas and Oklahoma.  Some fossils of Dimetrodon have also been unearthed in Germany.  It was a meat-eater, and the biggest individuals measured about ten feet long from snout to tail.  The name, Dimetrodon, translates to "Two Kinds of Teeth".  Despite this, Dimetrodon more accurately had three kinds of teeth. (womp-womp)

Dimetrodon grandis with the amphibian, Diplocaulus, as prey.  Reconstruction by Christopher DiPiazza.

If you ever had dinosaur toys as a child (or as a totally awesome not-boring adult, like myself) you might recognize Dimetrodon.  It stands out with it's lizard-like body and enormous fin along its back.  What many people don't realize is that Dimetrodon wasn't a dinosaur.  In fact, it was much more closely related to you, me, and my Yorkshire terrier than it was to any dinosaur.  Dimetrodon is oftern referred to as a "mammal-like reptile".  So it's still considered a reptile to a degree, but it was evolving characteristics that would eventually allow its relatives to become true milk-producing, hairy mammals by the time actual dinosaurs appeared on the earth, and eventually the many mammals we are familiar with today.

First of all, like I said above, Dimetrodon came and left (went extinct) about 40 million years before the first dinosaurs ever evolved on the planet.  In addition, Dimetrodon gives us good clues to what it really was in the bones alone.  The teeth, as the name implies, were differentiated, instead of uniform (what you would see in most other reptiles.)  As mammals, we too have different kinds of teeth in our mouths.  In the front of Dimetrodon's mouth, it had short teeth, similar to incisors.  On the sides it had long, canine-like teeth for slashing, and in the back the teeth were shorter, probably good for breaking up and processing chunks of other animals to be swallowed.  If you look at the rest of the skull, you would notice that it has nostril holes in the front, eye sockets towards the back, and another hole behind the eye sockets, called the temporal fenestra.  ("fenestra" means "window": fun fact)   This hole is present in all mammal skulls, as well.  (Yes, even yours.  We even call them "temples") Dinosaurs and their closest relatives,  have an additional hole between the eye socket and the nostril on each side, called the antorbital fenestra.

Dimetrodon grandis skull.  Note the differences in teeth and the temporal fenestra behind the eye socket.

Dimetrodon's legs were relatively short compared to its long body and large head.  The limbs could have been held erectly as it walked and ran, but it would have had to rest on its belly with them sprawled out to the sides, like a lizard or crocodilian.  Because of this, Dimetrodon probably wasn't capable of running very fast for long distances, but it wouldn't have needed to since all the animals it coexisted with were either just as slow, or slower.  When alive, Dimetrodon would have been the top predator of its environment (that we know of) and it probably would have regularly preyed upon other reptiles, amphibians, like Eryops, and even prehistoric sharks, like Orthacanthus.

Dimetrodon limbatus skeleton on display at the American Museum of Natural History in New York.

The most striking feature about Dimetrodon was its amazing fin, or sail, we call it, growing from its back.  This structure was made up of very long, thin extensions of its neural arches,  Neural Arches are the little top parts of the vertebrae bones.  You can feel your own if you run your finger down the middle of your back.  In life, these rod-like bony structures would have been covered with a thin layer of skin, giving it the sail appearance.  One reason why scientists think this structure evolved was to help regulate Dimetrodon's body temperature.  If there were blood vessels in the skin part of this sail in life, the blood would more easily be warmed when exposed to the sun, circulating to warm up the rest of the body faster, or the opposite if Dimetrodon was getting overheated and decided to go into the shade to cool off.  Since all of the other animals it coexisted with would have also been ectothermic, and would have needed time to heat up in the sun each morning, Dimetrodon's sail could have served as a good adaptation to give it a head start at becoming active each day, allowing it to hunt prey, which would have still been in an inactive state.  It's the same reason why it is always easiest to catch frogs and reptiles in the morning, when they are still warming their bodies up and can't move around as quickly as they would be able to midday. (Although I don't condone going out and trying to grab wild animals!)  Others question if the sail would really have been that effective at thermoregulation and suggest it was more likely just an adaptation for display within the species.  There are actually more than one recognized species of Dimetrodon, each sporting variances in the shapes of their sails.  That being said, there is a chance at least some of these variations, especially the ones that coexisted with one another, could have been different sexes and/or ages of the same species.

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

References

Angielczyk, K. D. (2009). "Dimetrodon is Not a Dinosaur: Using Tree Thinking to Understand the Ancient Relatives of Mammals and their Evolution". Evolution: Education and Outreach 2 (2): 257–271.

Baur, G.; Case, E.C. (1899). "The history of the Pelycosauria, with a description of the genus Dimetrodon, Cope".Transactions of the American Philosophical Society 20 (1): 5–62.

Florides, G.A.; Wrobel, L.C.; Kalogirou, S.A.; Tassou, S.A. (1999). "A Thermal Model for Reptiles and Pelycosaurs".Journal of Thermal Biology 24 (1): 1–13.

Olson, E.C. (1966). "Community evolution and the origin of mammals". Ecology 47 (2): 291–302.

Interview with Paleontologist: Susan Drymala

Today we have the treat of hearing from paleontologist, Susan Drymala!  Susan Drymala is a graduate student in vertebrate paleontology at North Carolina State University (now working towards her PhD) and the North Carolina Museum of Natural Sciences. Susan has a BS in geology from the University of Maryland and a MS from NCSU. She took a brief hiatus from academia between her BS and MS due to illness and ended up working for an aggregate mining company for a year and began the blog The Forgotten Archosaurs. Susan studies crocodile-line archosaurs (pseudosuchians), specifically Paracrocodylomorpha, and terrestrial ecosystems of the Triassic. She has done field work in the Triassic of Arizona, New Mexico, Maryland, and North Carolina and the Cretaceous of Utah and recently named a new species of large crocodylomorph.

 Question 1: Who did you admire growing up?

SD: I actually don’t remember having any major role models while growing up, other than the occasional teacher. I was a pretty shy kid.

Question 2: At what age did you get inspired to pursue a career in paleontology?

SD: I knew quite early on that I wanted a career in the natural sciences. I vividly remember visiting places like Yellowstone National Park and Dinosaur National Monument at age 5 and hanging on every word of the park rangers. I pretty much always envisioned a career in geology or biology and things slowly solidified over the years until sometime in high school when I was quite certain that paleontology was definitely the path I wanted to take.

Question 3: You are best known for working with pseudosuchians (as oppose to dinosaurs) from the Triassic.  Was this a part of the field that you had more interest in before you started research, or did the research choose you?

SD: When I started to really pursue paleontology as a possible career, there two things that I was certain of: I wanted to work on animals that were unusual/ poorly understood and I was really interested in mass extinctions. I DID NOT want to do Dinosaurs, since it seemed like everyone was working on them and I figured that there must be a lot of other cool critters that were even more mysterious out there to be studied. I knew that I didn’t want to do anything with humans, which for me meant that mammals were out of the question too; they’re too recent and too familiar. I wanted to explore further back in time. By the time I was a freshman at the University of Maryland, taking Historical Geology with Tom Holtz, my interest in extinction events and the less familiar side of paleontology brought my attention to the Triassic and to the pseudosuchians that dominated that time.

Question 4: What was your favorite prehistoric animal growing up?  Which is your favorite now?

SD: I never really had a particular favorite of much of anything while growing up. I’ve always been drawn to big predators though, so I’ve always liked big cats and theropods. Once I started reading about pseudosuchians, I was immediately drawn to the “rauisuchians”. I’m still not sure I have a favorite per se, but since my MS thesis and first publication were all about Carnufex, it will always hold a special place in my heart.

Life reconstruction of the pseudosuchian, Carnufex, by Christopher DiPiazza.

 Question 5: Paleontology is such a diverse field these days involving many disciplines.  What advice would you give to an aspiring paleontologist today?

SD: Paleontology can be a very difficult field to be in because it’s a field that so many are drawn to – I think because it is so interdisciplinary and it stirs our imaginations – and yet there is so little funding and so few jobs. When I first meet a lot of young people interested in going into paleontology, the conversation is often begun with one of the many paleo clichés such as “I’ve wanted to be a paleontologist since I was a kid” or “I really like theropods”. Although there’s nothing specifically wrong with that, I’ve noticed that a lot of profession paleontologists are turned off by these sorts of statements, so I try to get aspiring paleontologists to expand that childlike wonderment into the wonderment of a scientist and this includes a number of questions and bits of advice:

1.)   Are you a researcher? A lot of aspiring paleontologists don’t realize just how many different career paths you can take and still work in paleontology. And not all of them require a PhD. Sure, lots of paleontologists are professors and curators, but there are also preparators, collections managers, and paleo artists, to name just a few, and all require different skill sets and very different career paths. It’s important to get to know the field of paleontology as a whole before deciding on a career.

2.)   What do you want to study? Don’t just say “T. rex”. If you are a researcher – if you’ve got a lot of questions and ideas on how to answer them - there are three things to think about as far as area of study: time period, taxon, and methodology. If you want to go into research, you’ll need to choose a specific field from each of these areas. For example, I study the phylogenetics and paleoecology (methodology) of Triassic (time period) paracrocodylomorphs (taxon). You don’t have to choose just one topic per area and you can certainly focus more on one area than the other – plenty of paleontologists focus almost entirely on a certain methodology and will apply it to pretty much any taxon, while other will apply a whole host of methods to understand one particular taxon – but all three are important for budding paleontologists to consider.

3.)   In paleontology, you need to be both the jack of all trades (in order to land a job) and the foremost expert in one narrow field (to remain relevant as a researcher). Well trained paleontologists are employed in all sorts of areas, from teaching med school anatomy to managing the geological resources at a national park. Having a good understanding of a lot of different areas of study keeps you marketable but also makes you a better scientist, since you’ll have more tools to approach research questions with. I’ve made sure to get a good education in both geology AND biology for this reason. Being an expert in one area is also important though, because it makes the “foremost expert” in something, which means other scientists will come to you on that topic.

Question 6: Going to college these days and then on to grad school has become a daunting task.  Many people are unaware of how long it takes to make it to the finish line.  The rewards are great, but what would you say to someone pursuing professional studies after college?

SD: The question of “are you a researcher” that I discussed in the last question is really important here. There are plenty of ways into paleontology that do not require advanced degrees. Becoming a fossil preparator, collections manager, museum display designer, or paleo artist does not necessarily require a PhD. If you do want to go the academic route though, it is important to have those qualities of a researcher, that “spark” of inquiry and imagination found in a good scientist, but also a lot of energy. The road through grad school is hard and you have to learn a lot more just how to do good science. Like I said, you’ve got to be a jack of all trades. You’ve got to learn a lot of different sciences, but also a lot of other skills, like scientific communication (from writing scientific literature and grants to public outreach). 

 

Question 7: What was or is your favorite project?  Would you be able to tell us about some of your current projects?

SD: Carnufex has been my baby for the last 3 years. I’ve really enjoyed working on this animal because it really is helping to make sense out of the various carnivorous pseudosuchians of the Triassic. Because of Carnufex, I’ve been working pretty heavily on the phylogenetics and evolution of that area of the pseudosuchian tree. I’m hoping to have a new paracrocodylomorph tree out in the next year or two and I’ll definitely be talking about some of the modifications within the basal crocodylomorph part of the tree at SVP.

Question 9: Do you ever get criticized on any of your work?  How do you handle it?

SD: So far, I haven’t had any major criticisms of my science. I’ve been pretty fortunate to have some pretty big names as mentors and I’ve got a lot of great people rooting for me. I’m sure that once I get more of my phylogenetic work out there I might start to stir some things up, but that tends to happen a lot with phylogenetics. I generally just try to remind people of what the science says and how science works; I’m putting hypotheses out there and the data that’s available to support it, that’s all. I really think that it’s important to not let things get personal in science. People are equal; ideas are not. If the data doesn’t support a hypothesis, we should let go of that hypothesis.
Some people did react somewhat negatively to the implication that Carnufex might have been bipedal and there are two things that I’ve tried to address with this: (1) we never explicitly said that Carnufex was bipedal, but the media seems to have taken the artists reconstruction (which is more of a rearing pose than true bipedality) and ran with it, but also (2) we haven’t explicitly ruled out that Carnufex was bipedal because it’s not outside the realm of possibilities given the large skull, short forelimb, and the fact that plenty of other Triassic paracrocs were likely bipedal. I just try to remind people of what the science says, and what it doesn’t.
With the recent publicity of Carnufex, I’ve gotten a little bit of personal criticism, especially focused on my voice, which has been very interesting. When it comes to personal attacks, I generally prefer to not “feed the troll” and just turn the other cheek. However, I also don’t tolerate bullies and especially not those perpetuating negative stereotypes, so I will sometime respond to negative criticism, but I always try to stay civil. And fortunately, as I learned on Twitter recently, there are a lot of great paleontologists out there on social media willing to back me up.

Question 10: Jurassic Park and Land Before Time (opposite ends of the spectrum I know) were the movies I remember as a kid that fueled my passion for dinosaurs.  What was your most memorable movie, book or TV program that inspired you with regards to paleontology?

SD: I think that we probably grew up in the golden age for dinosaurs in the media. Not only did the late 80s and early 90s have some great dino movies (Jurassic Park, the Land Before Time, We’re Back! A Dinosaur’s Story, Prehysteria!) and TV shows (Dinosaurs, of course), but the Discovery Channel was also still showing real documentaries then too. Walking with Dinosaurs and the other associated documentaries were great to have around as I considered a career in paleo. I think all of these had a bit of a snowball effect on me.

Question 11: I remember meeting my first professional paleontologist.  Do you remember the first paleontologist you ever met?  Were you a nervous wreck? 

SD: I remember emailing Matt Carrano when I was in high school and thinking about becoming a paleontologist. I was so excited to get a reply. I kept a pint-out of that email for years. My next real encounter with a “real” paleontologist was when I met Tom Holtz at an open house for University of Maryland. At first I was nervous, but he was such a nice and energetic person who I had so much in common with that we became pretty fast friends and the nerve went right out the door.
I still get a little nervous when I meet some of the big names in paleontology. Even though I know I shouldn’t, it’s hard to not get a little nervous when you’ve seen these people on TV and you know that they’re such an important part of the community. I tend to be a shy person anyway.

Question 12: Dinosaurs and the animals that lived at the same time as them were amazing creatures.  Why do you feel they continue to fascinate us?

SD: From my own experience, I think that they speak to the innate explorer in all of us. Our imaginations love the unfamiliar and the prospect of discovery. And in a time when our world seems to be shrinking, prehistoric creatures remind us that there are still new things out there to be discovered. Paleontology is currently the only form of time travel.

Question 13: What is your favorite time period?

SD: I adore the Triassic. I could probably gush about it for hours. It begins and ends with two of the biggest mass extinctions of all time. It’s the time of Pangea, the only time in the history of life on land that all the continents were connected. It is a time when the holdovers of the ancient Paleozoic ecosystems (like synapsids, temnospondyls, and cycads) are still abundant and when most of the modern clades we are familiar with first appear, including turtles, mammals, and archosaurs. It’s a time when dinosaurs are around, but they have not risen to dominance yet. It’s the time of the pseudosuchians.

Question 14: What hobbies do you have? (not necessarily paleo-related) 

SD: I certainly adore science to no end, and although I don’t have much time for hobbies these days, I am fortunate that a lot of my hobbies are related to paleontology. Most of my hobbies involve travel, the outdoors, and art (of varying types). I get outdoors as much as possible to hike, camp, or rock climb (although I don’t have much time these days except for when doing field work). I’ve been to the 48 contiguous United States, 7 foreign countries, 5 tectonic plates, 3 hot-spot volcanoes, and a whole host of national parks and monuments. I enjoy just about all forms of art and have engaged in almost all except for music and the performing arts. I used to do a lot of painting with acrylics and oil paints, but have shifted to focus mostly on drawing. I also really enjoy sculpture and sewing.

One of Susan's acrylic paintings.

 

One of Susan's graphite sketches.

Question 15: Have you ever been to New Jersey? 

SD: Being from Maryland originally, I’ve been to NJ a number of times. Most of my experiences with the Garden State have involved to turnpike, but as an undergrad at UMD, I helped organize a geology club trip to the Franklin mine to collect minerals and we camped in a nearby state park, which was beautiful. It was a really great trip. 

Thank you, Susan!  To learn more, please check out her website, the forgotten archosaurs, and follow her on twitter.  Farewell until next time!