Thursday, June 28, 2018

Interview with Paleontologist Amy Atwater


Amy is the Paleontology Collections Manager – Registrar at the Museum of the Rockies in Bozeman, MT. Her research focuses on North American Eocene primates called omomyids. The closest living relatives of omomyids are tarsiers of SE Asia.  Atwater grew up in Eugene, Oregon and spent her summers in the John Day Fossil Beds National Monument where she fell in love with paleontology and being outside. She received a Bachelor’s degree in Geological Sciences and a minor in Anthropology from the University of Oregon Clark Honors College. At the UO she studied the drivers of Plio-Pleistocene mammalian diversity of the Great Basin and the Great Plains of the United States and studied body size changes in Eocene primate. Amy received her Master’s at the University of Texas at Austin where she studied Eocene mammals from West Texas and Southern California as a National Science Foundation Graduate Research Fellow. For her Master’s thesis, Amy described three new genera of Eocene omomyids from the Friars Formation of San Diego County.



Question 1: Let’s start from the beginning.  What was your earliest sign of interest in paleontology that you can remember?

AA: I remember being about 4 years old and looking for fossils in Utah (where I was born) and Michigan (where my parents are from) with my family. We visited the John Day Fossil Beds National Monument in eastern Oregon when I was 5 years old and I remember being mesmerized about all the different fossil mammals that have been discovered there.

Amy at age six

Question 2: Did you have any professionals or family members who served as role models when you were younger?  Do you still have any now?

AA: Ted Fremd, who was the park paleontologist for the John Day Fossil Beds National Monument for a long time, has always been a role model of mine, and still is to this day. I watched videos of him doing fieldwork when I was little, and then I was lucky enough to do fieldwork with him in the park as a high school student and during my time as an undergrad at the University of Oregon.

Question 3: Was there anything you did or learned as you were on your way to your current career that you feel got you to where you are?  By this I mean any sort of field experience, a class, networking with the right people, or possibly something different?

AA: I was lucky enough to be able to volunteer with the Student Conservation Association (SCA) at Arches National Park in Utah. I also was selected for a GeoCorps internship through the Geological Society of America in Denali National Park and Preserve where I was a paleontology/GIS technician. During graduate school I was a paleontology intern at Big Bend National Park in west Texas. My time volunteering for the NPS not only allowed me to meet a variety of scientists who became references for me, but I also gained tons of first-hand experience.
Networking is also extremely important. I have always been very proactive in reaching out to professionals in paleontology who I might be able to volunteer with, or who I share research interests with. Maintaining those connections is vital for your future, you never know who might help you land your dream job or connect you with a great collaborator. 

Question 4: Much of your professional experience is with prehistoric mammals, most notably Eocene primates.  Was this specific content within paleontology something you already planned on working with, or did it “choose you” in a sense?

AA: I have always loved mammals. Living and extinct. Spending my summers as a child in the John Day Fossil Beds really cultivated that love and I honestly didn’t care too much for dinosaurs until college. I was always drawn to human evolution during middle and high school, and that plus my experience with North American mammals made falling in love with Eocene primates like omomyids quite easy. Omomyids closest living relative are tarsiers, and who doesn’t love those bug-eyed prosimians?!

Fossil omomyid skull

Question 5: What was or is your favorite project in paleontology so far?  Would you be able to tell us about some of your current projects?

AA: I learn so much about myself with each project I take on! My first paper heavily relied on databases, which made me realize that I want to work on projects that actually involves handling real fossils.
I have a paper that is going to be out any day now on my master’s research, where I described three new genera of Eocene primates (omomyids) from Southern California. I wanted to see the omomyid material at the San Diego Natural History Museum, and when I got a chance to look at the specimens there, I realized they represent new taxa. I did the comparisons and measurements necessary to write up the Systematic Paleontology, and I also ran phylogenetic analyses to understand how these new taxa relate to other North American omomyids. Parsimony is the most common phylogenetic analysis used in paleontology, but parsimony doesn’t investigate the total solution space, it’s just looking for the shortest route. So in addition of parsimony analyses, I also ran Bayesian analyses in order to have a better understanding of the evolutionary relationships within omomyids. Now I am at Museum of the Rockies in Bozeman, MT, where I am studying a close primate relative called Plesiadapis, which lived before true primates during the Paleocene age.

Fossil bird track in Denali.

Question 6: Tell us about Mary Anning’s Revenge!  How did that start?

AA: Mary Anning’s Revenge is a collaboration between Dr. Meaghan Wetherell and myself. We started the blog in 2012 when I was finishing up my B.S. at the University of Oregon, where Meaghan had just started graduate school. Meaghan and I already knew each other, she had actually been my camp counselor at science camps in the John Day Fossil Beds National Monument back in the day, so we decided to live together in 2012. Meaghan and I have a lot in common, we love science but we aren’t fans of the horrid sexism and prejudice that is pervasive in paleontology. We decided that we could use a blog as our platform to get our voices heard, and during a brainstorming session I brought up Mary Anning and how much bullshit she had to put up with (I had just read Remarkable Creatures by Tracy Chevalier) and the name Mary Anning’s Revenge was born. 
The blog is mostly our commentary on current events in science, mixed in with a whole lot of sass and laughs. We like to balance humor with informed opinions on what it is like to be an underrepresented voice in paleontology, usually with lots of statistics and research papers cited to back up what we say. Now that Meaghan and I don’t live together (or even in the same state for that matter), we don’t post as regularly as in the early days. We make up for this with our Instagram and Twitter accounts. I run our Instagram (@Mary_Annings_Revenge) and Meaghan runs our Twitter (@MarysRevenge), which you can follow for our musing on life and for updates on our latest blog posts.

Amy and Dr. Wetherell in West Texas

Question 7: Despite being busy in the museum, you make time to frequently post educational snippets of information with photographs of specimens on social media.  Why do you think scientists being active on platforms like twitter and Instagram is beneficial?

AA: Science communication is hugely important. I get a lot of messages from parents who are so grateful that they can show my posts to their young daughters who are interested in paleontology. before social media, the image of paleontology is typically that of an old rich white dude, and our field has so much more to offer. I want to inspire underrepresented groups in paleontology and also show the general public there isn’t a cookie cutter mold for all paleontologists.

Question 8: Where have you traveled for your career?  Do you have a favorite destination when it comes to fossils?  Why?

AA: All of my paleontology research has been focused on North America, so I’ve traveled a lot within the United States. I have worked in Oregon, Utah, Wyoming, Texas, Montana, California, and Alaska. Alaska is probably my favorite places to do fieldwork. I felt so lucky to live in a place where I could hike mountains, look at the tallest peak in North America, see incredible wildlife, and find dinosaur tracks. One day we were headed to a track locality and we had 13 grizzly bear sightings. A momma with two cubs walked within 5 meters of me (I was with a group of 7 and we all had bear spray, we were very safe), it was a thrill and working out in the wilderness was a dream come true.  

Big Bend Cretaceous strata

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

AA: Yes, I get criticized on my work. I am very open to constructive criticism, it improves your science. The most obvious way I have received constructive criticism is through reviewers for my research papers. It can be hard to read all the comments and edits, and sure, I frequently need a beer or two to read all that. But I am confident in my ability to do scientific research, and I know that these suggestions are about my work, not myself, and I repeat that in my head (or out loud…) when I’m going through everything.

Question 10: Jurassic Park and The Land Before Time (opposite ends of the spectrum, I know) were just two of the programs I remember as a kid that helped fuel my obsession with paleontology.  Did you have favorite shows, movies, or even toys growing up that fueled your passion?

AA: I loved watching documentary shows, like Steve Irwin in The Crocodile Hunter, Kratt’s Creatures, Zoboomafoo, The Jeff Corwin Experience, Bill Nye The Science Guy, etc. My friends and I would make and film our own nature documentaries in elementary school, it was a blast. I remember always being drawn to the outdoors and natural history, and it has always bothered me how many nature docs feature men and hardly any women.
And I have to be honest, the Jurassic Park films never really did anything for me (keep in mind I was 2 years old when it came out), I never saw it until I was well into high school. While I think it’s cool how much JP gets the public excited about paleo, I have issues with the stereotypes that are still rampant in those films, which I think can be damaging for our field in the long run. I really want media to change the depiction of paleontologists.

Hunting for primate fossils in Wyoming.

Question 11: One of my pet peeves is when people assume paleontology doesn’t really do any real good in the grand scheme of things and is just a “for fun” science.  Do you think paleontology has a bigger part to than this?  How?

AA: Well, honestly I think films like Jurassic Park are largely contributing to that assumption. But I have seen how paleontology has larger importance than just entertainment. I study early primates that went extinct in North America about 35 million years ago. Today, primates are one of the most endangered group of mammals on the planet. If we want to work to understand and prevent the extinction of these incredible animals, then using the fossil record where we already have an extinction recorded in the rocks will dramatically enhance our conservation approaches for living primates. If we are serious about conservation, then we must use the past to inform our future. So much of life that has existed on Earth is now extinct, to me it seems obvious that we must study the past to understand and protect the modern and the future.

Question 12: Who was the first paleontologist you met?  How was that interaction?

AA: The first paleontologist I met was Ted Fremd. I was attending summer camp in the John Day Fossil Beds during elementary & middle school, and he would frequently stop by the camp for lessons and hanging out. Ted was and is so approachable and friendly. I remember thinking, “Oh my goodness, I can make a career out of spending all my time outside looking for fossils? And I can be funny and have an awesome life like Ted’s? SIGN ME UP.”

Excavating oreodont fossils in Oregon.

Question 13: Why do you think prehistoric animals are so influential to us today?

AA: I think we love that sense of discovery and mystery about what existed on the planet before us. I have never found buried treasure (though I found a message in a bottle once in Alaska, it was from a preacher and it said I was going to hell), but I like to think that discovering fossils gives a similar rush. I think paleontology also offers a wonderful combination of science and creativity, which is really appealing to a wide audience.

Question 14: What is your favorite prehistoric animal?  Was it different when you were younger?

AA: My current favorite prehistoric animal are omomyids, which are tarsier-like primates that lived across North America, Asia, and Europe during the Eocene. When I was younger I think I liked Lucy the most. I remember being in 6th grade learning about Australopithecus afarensis and thinking that was the coolest thing ever. It helped me feel connected to our planet, knowing that humans evolved like all other life and we can study our own rich history.

Omomyids in the lab

Question 15: If you could use a time machine to go back and pick only one prehistoric animal to bring back from history and observe alive and in person, which would it be and why?

AA: Omomyids. First, I believe these early primates were likely adorable and I’d like to see that beauty in real life. Second, I am fascinated, like a lot of scientists, about what the heck a species is. Being able to observe my study animal as it lived could shed a lot of light about how these creatures were related to each other.
Question 17: Back to the time machine.  This time you can go back to any place and time period and have a look at what the environment was really like.  Which one would you pick and why?
I would want to go back to North America during the PETM (Paleocene-Eocene Thermal Maximum). This slice of time was the warming part of the Cenozoic and it really catapulted many mammalian groups to diversify and expand, and I would love to see all of the factors contributing to that explosion of life.

Question 16: Which is your favorite museum?  Why?

AA: My favorite museum is the Museum of the Rockies in Bozeman Montana! I am biased, because I work here! MOR is great because it houses the most T. rex and Triceratops fossils in the world, AND it has lots of cool fossil mammals, too. Bozeman is also a really fun town with tons of amazing outdoor opportunities, like being so close to Yellowstone National Park.


Question 17: What hobbies do you have?  (Don’t have to be paleo-related.)

Finding fossil plants in Denali
AA: I am the type of person that has to have time away from paleo to do my best science. I need a balance, and I am a firm believer in focusing on all aspects of my wellness, not just my occupation. This means my weekends are my weekends and I fight the urge to be working all the time. It’s easy to burn out because science perpetuates this notion that if you’re not doing science all the time, then you aren’t being productive, and therefore you are a bad scientist! I know my science improves when I give myself a break, and when I take care of myself. I learned this the hard way, I had all sorts of mental and physical health problems in undergrad and graduate school, including lots of trips to the Emergency Room. That was my wake-up call, my life and my health are so much more important than science.
So to actually answer the question, I have always loved being outside, that’s how I recharge. I love rock climbing, bouldering, river rafting, hiking, climbing mountains, or just sitting by a creek in the sunshine with a beer in my hand. I love to scrapbook, I like making jewelry, and I really love to sew. Spending time with my significant other, my family, and my friends is extremely important to me. And sometimes I just want to be alone on my couch watching Rupaul’s Drag Race while painting my nails and eating ice cream.

Tuesday, June 19, 2018

Sinoceratops: Beast of the Week

This week we'll be checking out a large ceratopsian that truly stands out from its relatives.  Enter Sinoceratops zhuchengensis!

Sinoceratops was a ceratopsian dinosaur that lived in what is now China during the late Cretaceous, between 72 and 66 million years ago.  From beak to tail tip it measured just under twenty feet long and like all its relatives, it would have eaten plants when alive.  The genus name translates to "Chinese Horned Face" and the species name is in reference to Zhucheng, the city its remains were discovered in.

Sinoceratops reconstruction in watercolors by Christopher DiPiazza

There were lots of ceratopsian dinosaurs that flourished throughout the Cretaceous.  Sinoceratops is particularly special because it is so far the only known ceratopsid, the family that includes the large kinds of ceratopsians with prominent horns and frill ornamentation, that lived in what is now Asia.  All other known ceratopsids lived in North America.  There are lots of small ceratopsian species known from China from the early Cretaceous, and even the late Jurassic.  It is possible most ceratopsians migrated into North America via a land bridge that existed at the time, called Beringia, and a few stayed back to give rise to Sinoceratops. However, it is also possible, given Sinoceratops' similarities to North American taxa, that some large ceratopsids could have migrated back to China, reslutling in Sinoceratops.

Within ceratopsids there are two major varieties.  The chasmosaurines, are the ones with long frills, and generally have long brow horns and short nose horns. (although exceptions exist).  Triceratops, Chasmosaurus, and Pentaceratops are all examples of chasmosaurines.  Sinoceratops belongs to the other group, the centrosaurines.  Centrosaurines had proportionally taller snouts and generally had large nose horns and small brow horns.  Styracosaurus and Pachyrhinosaurus are both examples from this group.  That being said some older forms of this group had long brow horns and short nosehorns, like Nasutoceratops and Machairoceratops, suggesting that long brow horns were ancestral to ceratopsids before chasmosaurines and centrosaurines split. Sinoceratops is more similar to the later centrosaurines, with a long nose horn and short brow horns, supporting the idea that it shared a more recent common ancestor with the later forms, and therefore was more likely a result of migration back to Asia from North America, instead of being from a lineage that just stayed in Asia the whole time.

Very rough info-graph I put together showing how Sinoceratops ended up in China from North American centrosaurine ancestors.

Sinoceratops is known from a few skulls that show us really interesting horn ornamentation.  The long nose horn and small, basically nonexistent, brow horns are not unheard of in this kind of dinosaur.  However, Sinoceratops had what appears to be knobby structures above its nostrils just in front of the nose horn on either side.  Unfortunately the fossilized skull that has these isn't that well preserved and as far as I know, the texture of the fossil doesn't tell us if these were smaller horn structures, or just the shape of the underlying skull.  This leads to some variation in reconstructions by paleoartists.

Section of Sinoceratops' snout, showing the unusual bony knob just infront of the nose horn.  Photo courtesy of Dr. Andy Farke.

The frill sported a series of narrow horns at its top that grew forwards and curved downwards at the tips.  In addition, the frill, itself, had a series of bumpy knobs along the top and down its center which may have had a layer of keratin, forming shallow horns, in life.   

Close up of the top of Sinoceratops' frill.  In addition to the forward facing horns on the top, you can also see the raised areas on the frame of the frill that may have been shallow horns in life.  Photo courtesy of Dr. Andy Farke.

As usual, the exact purpose of these horns is unknown, but it is possible they were for display within the species, maybe for attracting mates and/or intimidating rivals.  The nose horn could have been a stabbing weapon against predators and the frill horns could possibly have helped by deterring hungry jaws away from the neck. That being said, if defense was the primary purpose for ceratopsid horns, we'd see more uniformity over the millions of years that this branch of dinosaurs evolved.  Display adaptations, however, evolve and change more rapidly.

Portion of Sinoceratops' skull, featuring the eye socket, nose horn, and the little bony knobs over the nostrils.  Photo courtesy of Dr. Andy Farke.

Sinoceratops is featured in the newest installment of the Jurassic Park franchise, Jurassic World Fallen Kingdom.  In the movie it is depicted with two holes in its frill.  Let it be known this isn't backed up by any evidence and almost certainly wasn't the case for the  real animal.  While there were two holes in the skull, like there are in most ceratopsians, they were almost certainly covered up by skin in life.

That is all for this week!  As always feel free to comment below or on the  facebook page.  Special thank you to Dr. Andy Farke for kindly providing the amazing photographs of Sinoceratops' fossil material used in this post.

References

Xu, X., Wang, K., Zhao, X. & Li, D. (2010). "First ceratopsid dinosaur from China and its biogeographical implications". Chinese Science Bulletin55 (16): 1631–1635. 

Wednesday, June 13, 2018

Beast of the Week Reviews Jurassic World Alive

Jurassic World has jumped on the wave caused by the mobile game sensation started by Pokemon Go.  "Jurassic World Alive" uses your phone's GPS to generate a map of your neighborhood (or wherever else you are at the time) with dinosaurs and other  prehistoric animals hanging out in various places.  You walk around until you are close enough to one to collect its DNA (which involves a target-shooting mini game) and then you use that DNA to generate your own specimen of that creature.  You can collect as many of these beasts as you like, make them stronger with more DNA, and even battle them, turn-based style, against other players.  (Although I'm not entirely sure you're really fighting other players.  The last Jurassic World game had a battle system they advertised as player vs player that turned out to be really against a computer once it was noticed how predictable everyone's opponent was.)

I've always seen dinosaurs walking around my neighborhood.  Good to confirm it wasn't just all in my head.  For a second there I thought I might be crazy!

Of course it also wouldn't be a Jurassic World game without freaky hybrids.  In this game you can use the DNA of two creatures to make monstrous hybrids.  Unlike in the last game where you sacrificed your two original creatures to make a hybrid, now you don't lose your original parent creatures when you create a hybrid.  (This is nice since I became rather attached to my Einiosaurus.)  Sometimes you can even combine hybrids you already made to create even weirder hybrids that are a combination of three creatures, instead of two.  To be fair, Indominous rex, from Jurassic World, was a combination of a Tyrannsoaurus, Velociraptor, Majungasaurus, cuddlefish, and a frog.  So think of that before you start whining about triple hybrids in this game.  Science Fiction!

Here's what comes out when you combine a ceratopsian with a pseudosuchian.  That's a thing you know now!

That's all well and good, but what about something for the pure of heart paleontology lovers?  Is this a game for them, too, or just casual Jurassic World fans?  Well I downloaded the game, have been playing it for a bit over a week now, and kept this question in mind the whole time.  Let's dive in!

First thing I want to bring up right off the bat that is that all the prehistoric animals in this game are referred to as a whole as "creatures" in this game, and not "dinosaurs".  This is appreciated since there are more than just dinosaurs to collect in this game, including plenty of pseudosuchians, synapsids, and amphibians.  It's a subtle detail, but it's also one that makes an impact on me.  Countless times I have seen games, toys, shows, movies, and any other kind of entertainment about dinosaurs and other prehistoric life refer to to the whole pool of subjects as "dinosaurs".  This is because the term, "dinosaur" is more charismatic and fun than "prehistoric animals".  I suppose Jurassic World has enough popularity going for it that it can afford to tell it like it is in this regard and not lose any downloads.  Good on them.

So how about the accuracy of the creatures?  The Jurassic Park/World franchise is notorious for making mistakes on accuracy, and sometime straight up actively choosing less accurate designs for the sake of what hey think is better entertainment.  With that in mind I will say up front that any creature that has been featured in any of the films appears in this game true to the way it did on the big screen, accurate or not.  So Dilophosaurus has a frill and spits poison, Velociraptor is featherless, Apatosaurus' neck is too thin...all the same inaccuracies in the movies that paleontology nerds, like myself, have been pointing out at nausea for the past twenty five years, are also in this game.  They do attempt to acknowledge the fact the Velociraptors are over-sized in the flavor text...that's something!  Right?

This fixes everything.  All you nerds can stop whining now.

THAT BEING SAID....when it comes to animals that are not featured in the films, and therefore don't need to uphold any sort of image for recognition sake...some (not all) are actually pretty darn good!  I said something similar in my review of the last mobile game about Jurassic World, two years ago.  This game has actually improved further, having significantly more passable models in this newest game.

Let's start with the most popular instigator of accuracy debates, feathers.  Almost every theropod, specifically coelurosaurians, that we know almost certainly had feathers in life, have feathers in this game.  I'm not talking about the lazy half-attempt few feathers on the head or arms either.  We're talking fully feathered dinosaurs here.  Creatures like Deinocheirus, Proceratosaurus, Utahraptor, and even some of the tyrannosaurids (on which feathers are debatable even scientifically speaking), like Lythronax, sport full coats of plumage.

Plenty of dinosaurs in this game have feathers. 

Frustratingly enough, like I said above, Velociraptor, which has possibly the strongest evidence for feathers in life, is portrayed just like it is in the films in all its naked glory.  I find this particularly amusing when you look at it next to other dromaeosaurids in the game that are portrayed fully feathered.

(top) Utahraptor is appropriately feathered (with a few minor detail mistakes) but sacred Velociraptor (bottom) is the same old naked it's been since the 1993.  Sigh.

In general their large theropods have improved.  Dinosaurs like Suchumimus (which is based on paleoartist, Julius Cstonyi's artwork for the Jurassic World website over two years ago), Megalosaurus, Majungasaurus, and Gorgosaurus are almost totally safe from criticism from me.   The only really glaring problem is that all their wrists are still wrong, with their palms facing down, instead of inwards.  But the the models of these large meat-eaters, especially when compared to those of the same taxa in the last Jurassic World game, are much more accurate.

(top) The pretty terrible excuse for a Megalosaurus from the Jurassic World mobile game, released in 2015, which looks like a warped Tyrannosaurus model.  Compare it to (bottom) the significantly better Megalosaurus in the new Jurassic World Alive game, which is much more accurate.  This is just one example.  Many of the large theropods are much more accurate compared to the last game.

Some of the ornithopod dinosaurs are also really well done.  The one that I was impressed the most by was Edmontosaurus.  I love how the beak actually angles down beyond where the skull's beak would end, which is consistent which what we now know based on a nicely preserved specimen of this dinosaur, now on display in Los Angeles, that shows the keratin beak on top of the bone, proving that it didn't have simply a flat "duck bill".  This is something lots of portrayals of this animal (even scientific ones) get wrong. The Edmontosaurus in this game also has the row of raised scallop-pattern scales running down the back which is also consistent with known hadrosaur fossils.  Nice!

That's a decent hadrosaur!

Of course there are still some models that are just as bad as they were in the last game...or just bad on their own.  The amphibians, like Diplocaulus and Koolasuchus, or some of the pseudosuchians, like Nundasuchus and Postosuchus, come to mind.  The sauropods, ceratopsians, and thyreophorans, while not flat out horrible, all suffer from somewhat subtle inaccuracies in their general anatomies.

At the end of the day, despite how frustrating it is, Jurassic World isn't trying to be scientifically accurate, especially if it gets in the way of what they think will get them better ratings and more money.  That being said, after looking at this game, it is evident that at least some people on creative design team definitely did their homework about these animals and applied what they learned where they could.  This attention to detail is a refreshing oasis of fleeting scientific accuracy in a desert of ignorance.  This game isn't going to fix everything, but it has its positive aspects that the latest movies don't.  Just like with Pokemon Go, it encourages people to go outside and interact with their surroundings, plus it can also help some newer paleontology fans of all ages learn the names of some creatures they may not have known about before. 


Sunday, June 10, 2018

Dilophosaurus: Beast of the Week

This week we will check out a dinosaur that is unfortunately, despite its popularity, is very poorly understood by the general public.  Make way for Dilophosaurus wetherilli!

Dilophosaurus was a meat-eating dinosaur that lived in what is now Arizona, in western North America, during the early Jurassic Period, 193 million years ago.  Trace fossils, like footprints and even a belly imprint of a dinosaur sitting down from the east coast of the United States have also been associated with Dilophosaurus. (or a dinosaur very similar to Dilophosaurus from what we can tell)  The largest specimen measures about twenty three feet long from snout to tail.  The genus name translates to "Two Crested Lizard/Reptile" in reference to the fact that this dinosaur had two, parallel, half-disc-shaped crests on the top of its snout.  The species name is in honor of John Wetherill, a Navajo councilor from near where Dilophosaurus' bones were first found.

Dilophosaurus wetherilli temporarily being startled by a Protosuchus.  The inner monologue here is something like "GAH!...OH, YUM!"

Dilophosaurus was the largest known member of the coelophysoid family of theropod dinosaurs.  Coelophysoids were meat-eating dinosaurs that were highly successful during the late Triassic and early Jurassic periods.  They all were relatively lightly built, had low, narrow snouts, long necks, tails, and legs, hollow bones, and three clawed fingers and one vestigial finger on each hand.  Other examples of coelophysoids are Coelophysis and Liliensternus.

Dilophosaurus' skull is striking.  The first thing you notice are those two crests that grew from the top of the snout.  These crests were made of very thin bone, and probably were too delicate to be used as any sort of weaponry in life.  That being said, they were most likely a kind of display adaptation within the species.  Unfortunately we don't have a large enough pool of complete Dilophosurus skulls to say if they were present in both sexes or not, but they are present in all the complete adult Dilophosaurus skulls on the fossil record so far.

Partially reconstructed Dilophosaurus skull mount on display at the American Museum of Natural History in New York.

Dilophosaurus had a long, slender snout with long, curved teeth that were compressed laterally.  They appear to have been great at slashing and puncturing, but not ideal for crushing or taking any sort of hard impact.  This doesn't seem to have been too much of an issue for Dilophosaurus when you think about its known environment, however.  It was the largest known predator in its environment.  All its prey consisted of much smaller animals, including small, early crocodilians, amphibians, mammals, and sauropodomorph dinosaurs that were about half Dilophosaurus' size.  So Dilophosaurus wouldn't have needed to have had bone-crushing jaws to tackle large prey, because everything it would have been hunting that we know of could have been overpowered with relatively little effort once caught.  In fact, the shape of Dilophosaurus' upper jaw has a deep notch just before the nostril.  This jaw has convergent evolved in other dinosaurs, like spinosaurs, which we know were eating fish in life.  There is a strong possibility that Dilophosaurus was a fisher as well.

Dilophosaurus holotype specimen.  Photo by of Eduard Sola.

One specimen of Dilophosaurus shows multiple injuries that had healed in life.  These include fractures, bony tumors, and even a deformed finger on the right hand.   All of these injuries were concentrated on the arms, hands, and shoulders.  This supports the idea that Dilophosaurus may have used its arms and front claws the most for fighting or subduing prey.  Or maybe it just took a nasty fall or ran into a tree?  Regardless, the point is Dilophosaurus was capable of taking a beating and shaking it off to survive years later!

Oh, and one more thing.  Dilophosaurus was one of the main dinosaurs in the original Jurassic Park.  Its being featured in this movie was sort of a double-edged sword.  On the one hand, an obscure dinosaur, that not many people were familiar with outside the paleontology community, suddenly became insanely popular amongst the general public, and is still highly regarded to this day.  On the other hand, it was portrayed horribly inaccurately, sporting a retractable frill, similar to that of a modern Frilled Lizard, and had the ability to spit venom.  Neither of these features are supported by any fossil evidence whatsoever and were completely made up in the name of showbiz.

References

Milner, A. R. C.; Harris, J. D.; Lockley, M. G.; Kirkland, J. I.; Matthews, N. A.; Harpending, H. (2009). "Bird-like anatomy, posture, and behavior revealed by an Early Jurassic theropod dinosaur resting trace". PLOS One. 4 (3): e4591.

Rothschild, B.; Tanke, D. H.; Ford, T. L. (2001). "Theropod stress fractures and tendon avulsions as a clue to activity". In Tanke, D. H.; Carpenter, K. Mesozoic Vertebrate Life. Bloomington: Indiana University Press. pp. 331–336.

Senter, P.; Juengst, S. L.; Heymann, D. (2016). "Record-breaking pain: the largest number and variety of forelimb bone maladies in a theropod dinosaur". PLOS One.

Welles, S. P. (1984). "Dilophosaurus wetherilli (Dinosauria, Theropoda), osteology and comparisons". Palaeontographica Abteilung A. 185: 85–180.