Sunday, February 25, 2018

Herrerasaurus: Beast of the Week

Today we will be looking at one of the earliest dinosaurs.  Enter Herrerasaurus ischigualastensis!

Herrerasaurus lived in what is now Argentina, in South America, during the Triassic Period, roughly 231 million years ago.  The largest specimen on record would have been about twenty feet long from snout to tail, but all adults may not have reached this size, possibly averaging out at around fifteen feet.  When alive Herrerasaurus would have eaten meat, according to its teeth.  The genus name translates to "Herrera's Reptile", in honor of the goat herder who discovered the first bones of this dinosaur, Victorino Herrera.

My Herrerasaurus ischigualastensis life reconstruction in watercolors.

Herrerasaurus had a boxy profile to its skull, which was armed with a lower jaw that was able to flex back and fourth.  This is an unusual adaptation for dinosaurs, but is common in many modern lizards, like monitors, to help manipulate large chunks of food to the back of the mouth to be swallowed.  (lizards evolved this trait independently of Herrerasaurus, however.)  Herrerasaurus was also armed with extremely long, dagger-like teeth, that curved towards the back of the mouth, another quality of a meat-eater.  

Cast of the first discovered Herrerasaurus skull on display at the Academy of Natural Science in Pennsylvania.

Herrerasaurus had strong arms, each armed with three curved claws.  It had proportionally short thighs, and long lower legs and feet, suggesting it was a fast runner in life.  It's tail was not very flexible because of the bony structures in its vertebrae, which is also a characteristic of dinosaurs that were good runners, to aid in maneuverability.  

Herrerasaurus had a number of odd characteristics about its anatomy that have caused scientists to dispute over what kind of animal it really was.  It walked in a fully erect posture, like all dinosaurs, but the socket where its femurs attached to its pelvis was not as open, or "window-like", as it is with later dinosaurs.  It also only had two vertebrae over its hips, called sacral vertebrae, whereas most dinosaurs typically have three.  Lastly the bone int its hip, called a pubis, was angled behind the body, which is typical in ornithiscian dinosaurs, dromaeosaurs, and birds, the last two wouldn't evolve until millions of years after Herrerasaurus.

Herrerasaurus mounted skeleton on display at the Field Museum in Chicago.

Herrerasaurus is one of those fossil creatures that has gone through a few identity crises over the years since its discovery.  Because it lived so early on in the Mesozoic, before dinosaurs started truly diversifying, it has proven tricky to place, genetically.  At first, because of its teeth and long legs, it was classified as a very early theropod.  However, some suggested it had more in common with early sauropodomorphs, like Plateosaurus.  Some have suggested that Herrerasaurus, despite its meat-eating qualities, was actually closest to ornithiscian dinosaurs, because of its backwards-facing pubis bone.  It was even proposed to be not a dinosaur, at all, placed just outside the dinosaur family tree and classified as something more closely related to crocodiles due to more basal traits in its skull and hips.  However, as more and more fossils from the Triassic are being unearthed, the latest analysis of Herrerasaurus places it back as a dinosaur,  almost at the very base of the dinosaur line, as a kind of very early sauriscian dinosaur.

References

Benedetto, J.L. (1973). "Herrerasauridae, nueva familia de saurisquios triasicos" (PDF). Ameghiniana. 10 (1): 89–102.

Bittencourt, J.S.; Arcucci, A.B.; Marsicano, C.A.; Langer, M.C. (2014). "Osteology of the Middle Triassic archosaur Lewisuchus admixtus Romer (Chan~ares Formation, Argentina), its inclusivity, and relationships amongst early dinosauromorphs". Journal of Systematic Palaeontology. 0 (3): 1–31. 

Gauthier, J.A.; Nesbitt, S.J.; Schachner, E.R.; Bever, G.S.; Joyce, W.G. (2011). "The bipedal stem crocodilian Poposaurus gracilis: inferring function in fossils and innovation in archosaur locomotion" (PDF). Bulletin of the Peabody Museum of Natural History. 52 (1): 107–126. doi:10.3374/014.052.0102. Archived from the original (PDF) on 2015-09-24.

Gilmore, Charles W. (1920). "Osteology of the carnivorous dinosauria in the United States National Museum, with special reference to the genera Antrodemus (Allosaurus) and Ceratosaurus". Bulletin of the United States National Museum. 110 (110): 1–159. 

Nesbitt, S. J.; Smith, N. D.; Irmis, R. B.; Turner, A. H.; Downs, A. & Norell, M. A. (2009). "A complete skeleton of a Late Triassic saurischian and the early evolution of dinosaurs". Science. 326 (5959): 1530–1533.

Novas (1993). "New information on the systematics and postcranial skeleton of Herrerasaurus ischigualastensis (Theropoda: Herrerasauridae) from the Ischigualasto Formation (Upper Triassic) of Argentina". Journal of Vertebrate Paleontology. 13: 400–423.

 Novas, F.E. (1994). "New information on the systematics and postcranial skeleton of Herrerasaurus ischigualastensis (Theropoda: Herrerasauridae) from the Ischigualasto Formation (Upper Triassic) of Argentina". Journal of Vertebrate Paleontology. 34 (4): 400–423.

Padian, K.; May, C.L. (1993). "The Earliest Dinosaurs". In Lucas, Spencer G.; Morales, M. The Nonmarine Triassic. New Mexico Museum of Natural History & Science Bulletin. 3. pp. 379–381.

Sereno, P.C.; Novas, F.E. (1993). "The skull and neck of the basal theropod Herrerasaurus ischigualastensis". Journal of Vertebrate Paleontology. 13 (4): 451–476.

Saturday, February 24, 2018

Let's Publish The Old Kingdom!

Cretaceous North Africa, home to the largest meat-eating dinosaur known to science, Spinosaurus, was a fascinating environment from which we have a wealth of fossils and information from.  Despite this, never before has there been a textbook strictly dedicated to this fascinating time and place in earth's history.  That is before paleontologist, Jamle Ijouiher, decided to compile all his research on this subject into one amazing textbook for anyone to buy and own in his/her own collection of reading material!

Jamale is a rare gem because he used his own funds to get this book published.  He also insisted on fairly paying his artists whom he hired to provide the illustrations for this book.  (I am one of said artists.)

My Spinosuarus aegyptiacus is one of the illustrations featured in Jamle's upcoming book, The Old Kingdom.  Click the link below to donate and ensure it gets published!

Because of this, Jamale needs our help to get this book through the last stages of publication.  Check out this link and read more about his mission to get his book published and contribute a donation if you can!  It will be helping paleoartists, like myself, scientists, like Jamale, and take us one step in the right direction of having good scientific material available for anyone who wants it. 

Sunday, February 18, 2018

Pteranodon: Beast of the Week

Today we will be looking at the most iconic pterosaur of all.  Check out Pteranodon longiceps!

Pteranodon was a large pterosaur (prehistoric flying reptile that was not a dinosaur.) that lived in what is now central United States, including Kansas, Alabama, Nebraska, Wyoming, and South Dakota, during the Late Cretaceous Period, between 86 and 84.5 million years ago.  The biggest Pteranodons on record have wingspans of over twenty feet from tip to tip, but average males were more close to eighteen feet and the females (Yes, we are pretty sure we can tell the two sexes.  More on that later.) were a bit smaller, with about a twelve foot wingspan.  When alive Pteranodon would have been a meat-eater, feeding on fish and other marine prey that lived in the shallow sea that once covered the region of the the country that Pteranodon would have flown over in life.  The genus name, Pteranodon, translates to "Toothless Wing" because...wait for it...it didn't have any teeth and it had wings.  Ironically there are way too many pop culture representations of this animal that have teeth!

Two male Pteranodon longiceps fight over a cephalopod.  Reconstruction by me in watercolors.

Pteranodon is a very well-studied animal, known from over one thousand fossil specimens!  Among these individuals we find two body types.  One type is the most iconic vision of this animal, being the larger of the two, with an average wingspan of eighteen feet (but some are larger as stated above) with a long, pointed crest growing out of the back of the skull.  The second body type is much smaller, with only a twelve-foot wingspan. (Still huge if you consider the largest flying animal today, the Wandering Albatross, has a wingspan just under that.) These smaller individuals also had a short, blunt crest behind the head and wide hips, even wider when compared to their in every other way larger crested counterparts.  At first it may seem there were two species of related pterosaurs sharing the same environment, but upon closer inspection, the evidence is pointing to one species that was sexually dimorphic.  (sexual dimorphism- when the males and females of a species look different.) The the larger, crested type was the male, and the smaller, short-crested, was the female.  Why do we think these two forms were different sexes of the same species and not simply two different species?  Let's look at the three key differences between them I listed above.

Skeletal mount of a female (probably) Pteranodon hanging from the gift shop ceiling of the American Museum of Natural History in New York.

1) Size
This isn't actually an indicator of sexual dimorphism by itself.  This is because within reptiles, there are many examples of female-larger and male-larger species across the board.  Sometimes even within the same genus of reptile there are variations with male and female size dimorphism.  So that one is out as far as evidence goes.  Let's look at the other two clues.

2) Crests
In almost all animals that use display structures like colors, frills, horns, manes, or crests as a difference between the sexes, the males are the ones that have more going on. Don't misunderstand me here!  There are plenty of species where both the males AND females have cool structures...it's just in the ones that there is a difference between the two, the males are the ones with the more visually intense bits to show potential mates how healthy they are.  It's more biologically taxing to be the female, carrying and giving birth, so males are often the ones competing for their attention, instead of the other way around.  If these two forms were opposite sexes, the ones with the long crests would more likely be the males.

3) Hips
This is the strongest piece of evidence.  The smaller individuals with short crests had wider hips.  Wider hips are found in females of almost any species of vertebrate for giving birth.  In this case, wider hips would make it easier for those individuals to carry and lay eggs.  The fact that they are specifically wider than those of the other body type that is larger in every other way, including a cool display crest, strongly suggests we are looking at males and females of the same species.


Sketch I did in graphite of a female (probably) Pteranodon longiceps.

Beyond being one of the few fossil species we can pretty confidently distinguish the males from the females in, Pteranodon had a number of other cool things going on with its anatomy.  Let's start with that beak.  It was huge!  In fact, Pteranodon's skull is much longer than the rest of its body!  A beak like that, combined with the evidence that this animal spent much of its life soaring over the sea, would have been excellent for snatching up fish and other small marine prey.  Pteranodon may have even dove for its food, using its beak like a spear to catch prey even deeper under the water's surface.  Having a long beak is a helpful adaptation for a predator hunting prey in the water because it greatly extends the striking range without having to move the whole body much.  To further support the idea it was a fish-eater, fish bone and scale fossils have been found in the stomach cavities of Pteranodon specimens.

Pteranodon mount on display at the American Museum of Natural History in New York.

Pteranodon had particularly long wings, even for a pterosaur, because it was adapted for soaring long distances.  We can see parallels in flying animals, like birds, today.  Birds that live most of their lives soaring over the ocean, like albatross, have long, tapered, wings, as well.  Like them, it is likely Pteranodon was capable of going long distances without flapping.  It may have even been able to sleep while flying!  (although we don't have direct proof of that)  That being said, the arm bones of Pteranodon suggest it had HUGE muscles there in life, so flapping wouldn't have been a problem for this pterosaur, either, if i t needed to do so.

Pteranodon longiceps male (probably) skeleton hanging in the American Museum of Natural History's temporary pterosaurs exhibit.

Since all the Pteranodon fossils on record were unearthed in an area that would have been a sea during the times of their deaths, we can logically assume Pteranodon spent most of its time flying over water, probably resting and nesting on islands or rocky cliffs surrounded by, or near the water.  While Pteranodon, itself, was an adept predator, it had to watch out when it got near or in the water for the gigantic sea monsters it shared its world with.  Most notable was the mosasaur, Tylosaurus.

Lastly, please don't refer to Pteranodon as "pterodactyl".  Too often are pop culture depictions of pterosaurs labelled as "pterodactyl", but are clearly based on Pteranodon.  Seriously, if you say "pterodactyl" that in front of a paleontologist, he or she will no doubt correct you with a pleasant smile, but I promise you that poor scientist is screaming inside.

References

Bennett, S.C. (1992). "Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests". Journal of Vertebrate Paleontology. 12 (4): 422–434. 

Bennett, S.C. (1994). "The Pterosaurs of the Niobrara Chalk". The Earth Scientist. 11 (1): 22–25.

Bennett, S.C. (2000). "Inferring stratigraphic position of fossil vertebrates from the Niobrara Chalk of western Kansas." Current Research in Earth Sciences: Kansas Geological Survey Bulletin, 244(Part 1): 26 pp.

Tomkins, J. L.; Lebas, N. R.; Witton, M. P.; Martill, D. M.; Humphries, S. (2010). "Positive Allometry and the Prehistory of Sexual Selection". The American Naturalist. 176 (2): 141–148.

Witton, M.P.; Habib, M.B. (2010). "On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness". PLoS ONE. 5 (11): e13982.

Tuesday, February 13, 2018

Safari Ltd Review: Pachyrhinosaurus

It is time for Prehistoric Beast of the Week's second installment of Safari Ltd dinosaur toy review!  This time we will check out Safrari's rendition of Pachyrhinosaurus, which they generously sent to me to review for you all.

Pachyrhinosaurs was a ceratopsian dinosaur, in the same general group that includes the most famous Triceratops, that lived during the Late Cretaceous in what is now North America.  There are currently three named species, all from North America.  One of these species, the youngest one, Pachyrhinosaursu perotorum, is known from remains found in Alaska!  Pachyrhinosaurus has gained popularity in the mainstream thanks to the relatively recent Walking with Dinosaurs 3D movie, which starred Pachyrhinosaurus.  In fact, when I use Safari's Pachyrhinosaurus toy to help me teach visitors at the museum, many kids I teach instantly can identify it because of that movie!

Wild Safari has gotten better and better over the years at sculpting their ceratopsians.  Their Pachyrhinosaurus is definitely one of the best toys of this genus out there, which was originally released in 2014.



The first thing I notice about this figure is the texture of the skin.  It is covered in small mosaic-like scales.  among these are fewer, larger scales, creating rosette-like patterns on the dinosaur's body.  The sculptor did not make this up.  There are actually a few ceratopsian mummies on the fossil record that preserved skin and skin imprints that match this texture.  Among them are Triceratops, Chasmosaurus, and most relevant in this case, Centrosaurus, which was most closely related to Pachyrhinosaurus.  So while no skin from Pachyrhinosaurus, specifically, is known, and technically there is a chance its skin could have been different from this, the sculptor was using logic and research when creating this piece which is always appreciated. (and makes for a great teaching point from an educational standpoint.)

The top photo is of real fossilized Centrosaurus skin at the American Museum of Natural History.  The bottom image is a close up of Safari ltd's Pachyrhinosaurus' skin texture.  Homework was definitely done.

Pachyrhinosaurus is probably best known for its unique head ornamentation.  Unlike many other ceratopsians, which had horns on the nose and over the eye sockets, Pachyrhinosaurus had a wide mass of bone, called a boss, on its snout.  This boss would have increased the surface area of the dinosaur's face and probably made a great tool for applying blunt force to whatever the dinosaur chose to ram into when alive.  The frill of Pachyrhinosaurus, however, was adorned with horns, especially a pair of curved ones on the top.  Safari's model also sports three small horns right in the middle of the shield part of the frill.  These middle horns are only present in one species of this genus, Pachyrhinosaurus lakustai.

The three horns right in the middle of this model's frill give it away as Pachyrhinosaursu lakustai, specifically.

The other thing that Wild Safari has been getting right about its ceratopsians lately that many other toy companies still fall short on is the number of claws on the front limbs.  Ceratopsians have five fingers on each hand, but only the first three of those fingers on each hand actually possessed  claws.  This model showcases that correctly.  The angle at which the front limbs are positioned is also accurate, being slightly bent to the sides.

Ceratopsians, like all known dinosaurs...and archosaurs in general actually, had claws on only the first three fingers of each hand.

The one thing that I would complain about on this model would be its lack of bulk.  Large ceratopsians, like Pachyrhinosaurus, were notably robust creatures with wide hips.  Safari's model is too narrow when viewed from both front and side angles.  Overall it gives the appearance of a much more gracile animal than it probably would have been in reality.

That is all for this time!  If you are interested in grabbing one of these awesome guys for yourself, they are sold at most educational toy stores, or visit Safari ltd's website here!


Monday, January 22, 2018

Laganosuchus: Beast of the Week

Today we will be checking out a wonderfully specialized prehistoric crocodile.  Check out Lagaosuchus thaumastos!

Laganosuchus lived in what is now Niger, Africa, during the Cretaceous period, about 95 million years ago.  According to the known fossil material, adults could grow to be over twenty feet long from snout to tail.  Like most crocodiles, Laganosuchus would have been a meat-eater when alive.  The genus name, Laganosuchus, translates to "Pancake Crocodile" because of the shape of its snout.  When alive, Laganosuchus would have shared its habitat with fellow crocodilian, Kaprosuchus, and the plant-eating dinosaur, Nigersaurus.

My Laganosuchus life reconstruction in watercolors.  This poor fellow was part of a larger painting...as prey for a Spinosaurus.

Laganosuchus didn't earn the name, "Pancake Crocodile", for nothing.  This crocodile's jaws were extremely wide and shallow, causing it to have an extremely flat head.  The jaws were lined with small, pointed teeth.  This suggest that Laganosuchus was adapted to hunting fish in a specialized manner.  The leading hypothesis as to exactly how Laganosuchus did this is that it would lie still in the water for extended periods of time with its mouth ajar, becoming part of the environment for passing fish.  As fish became more and more comfortable around it, they would be more comfortable swimming closer and closer to the mouth.  Some may have even swam inside the mouth, seeking refuge in the seemingly cave-like structure.  When this happened, Laganosuchus could shut its jaws lightning-fast, catching and eating any fish unfortunate enough to be too close at the time.  Laganosuchus and its proposed hunting style always reminded me of this scene from the Jim Henson movie, The Dark Crystal.  Watch at twenty five seconds in if you want to see what I mean.



Unlike many other species of crocodilian, who's jaws are strong and good at holding tight under pressure, the jaws of Laganosuchus are rather thin and delicate.  This further supports the idea that this crocodile wasn't hunting large prey, rather focusing on smaller fish and other animals instead.  It's contemporary and neighbor, Kaprosuchus, may have filled that niche of going after larger prey with its shorter, but more powerful jaws and proportionally larger teeth.

Lower jaw of Laganosuchus featured in Paul Sereno's 2009 paper.  Note how thin it is and how proportionally small the tooth sockets are.  This crocodile was probably specialized in hunting smaller fish.

Laganosuchus is an important find because it helps break the false idea that crocodilians remained completely unchanged through the Mesozoic to today.  Yes, they have been around since then, but they were far from stagnant in their evolution.  Crocodilians experimented with many different forms during their history on earth, and as is the case with Laganosuchus, some were extremely specialized.

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

References

 Sereno, P. C.; Larsson, H. C. E. (2009). "Cretaceous crocodyliforms from the Sahara". ZooKeys. 28 (19 November 2009): 1–143.

Friday, January 19, 2018

Interview with Marine Biologist: Melissa Marquez


Today we have the honor of getting to know Melissa Marquez, a marine biologist, most famous for her work with sharks!

Melissa Cristina Marquez is a Latina marine biologist and wildlife educator with a BA (Hons) in Marine Ecology and Conservation degree from New College of Florida, USA and an MSc in Marine Biology from Victoria University of Wellington, NZ. Marquez currently resides in Sydney, Australia.

She is a freelance environmental contributor, wildlife artist, aspiring children's book author, and founder of The Fins United Initiative (TFUI; www.finsunited.co.nz), a program that brings attention to the unusual and diverse sharks (and their relatives) of the world and the threats they face. Marquez is also host of the Spanish marine conservation podcast, ConCiencia Azul. You can follow her adventures around the world on Twitter (@mcmsharksxx).



Question 1: At what age did you become interested in sharks?  Were they always a passion of yours? 

MM: I grew up watching David Attenborough documentaries and The Wild Thornberry’s on Nickelodeon. When I moved to the USA from Mexico I got to watch Shark Week for the first time and became hooked on sharks! My first love was manatees, though… but they just didn’t end up exciting me as much as Chondrichthyans (sharks, skates, rays, and chimaeras).

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?

MM: People like David Attenborough, Sylvia Earle, and Eugenie Clark are big role models I’ve looked up to. Now, while those three have been instrumental to my pursuing of marine biology, I also have colleagues that I also look to as role models.

Melissa gearing up for a shark dive in the Bahamas.

Question 4: 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 or all three?

MM: I think networking is the best skill I’m using and is allowing me many of the opportunities I’m getting today. Of course everyone needs to take advantage of field experiences (such as internships) and take certain classes (I recommend learning R-programming and ArcGIS for an edge in graduate school). But networking is an art and can be hard to do! I talk about networking tips that worked for me in these three (One, Two, Three) articles for my #STEMSaturdays series with femSTEM.

Question 5: Is the field of marine biology different now than from when you started as far as you can tell?  How about from when you were a child? 

MM: I don’t think it has changed in that you still have passionate scientists trying to unravel the mysteries of this massive ecosystem that sustains our planet. If anything, it has changed for the better—programs like Blue Planet have brought the magic of the ocean to everyone’s fingertips and has inspired many to come study and help protect the ocean.

 
One of my favorite TEDx Talks was Melissa's about the representation of female scientists in marine biology.

Question 6: What was or is your favorite professional experience so far?  Would you be able to tell us about some of your current projects?

MM: I think getting to do dorsal fin ID with great white sharks and inputting all that data into a dataset to be analysed was the moment where I realized, “Holy crap, my field is really cool and this is what I want to do for the rest of my life.” I’m currently looking for a PhD position, so I’ll tell you some of the science communication outreach projects I’m a part of:
·       The Fins United Initiative is a shark, skate, ray and chimaera education and conservation program aiming to unite fin lovers worldwide. Through partnerships with K-12th grade educational institutions, The Fins United Initiative provides easy-to-access materials that educators can use in their classrooms.
·       Little Fin Fighters: A collaboration between the organisation Keep Fin Alive and The Fins United Initiative in educating younger generations about plastic pollution and how to reduce their plastic pollution footprint.
·       Shark Bites Book Club: The Fins United Initiative is proudly teaming up with authors around the world to introduce The Shark Bites Book Club to promote and encourage science literacy in all ages.
·       ConCiencia Azul: The Spanish version of Speak Up For Blue Podcast. ConCiencia Azul interviews Latinx* marine science researchers and we discuss ocean-related topics, as well as speak about some of the unique hardships Hispanic/Latinx countries face.  The show will post a new episode once a week starting February 2018. // *Note: Latinx is a gender neutral term often used in lieu of Latino or Latina.
·       Writing efforts: This upcoming year, in-between my jobs, I will be putting much of my effort into becoming an author and writing books that will help promote and encourage science literacy in all ages.

Melissa giving her "Shark Talk" to a group


Question 7: You have traveled to a lot of interesting places around the world for your research.  What was your favorite traveling experience so far?  Do you see yourself traveling more in the future?

MM: I honestly can’t pick just one favourite traveling experience- they are all treasured for one reason or another. I’m fortunate enough to have traveled to over 20 countries in my short life. But I do hope I continue to get to travel in this line of work. Currently I have a conference in Malaysia in June lined up; I may go to another conference in Brazil, too.

Melissa doing field work in Mexico

Question 8: What is the biggest misconception about your line of work that you find people tend to believe? 

MM: Many people think marine biologists are constantly out at sea with animals and that just isn’t the case. Like most scientists, we spend a fair bit amount of time inside (writing, analysis of data, doing research, applying for funding grants, etc).

Question 9: How much of your work takes place in the field with the animals vs. in a lab setting?

MM: The majority of my time is spent behind a computer analyzing data and creating science outreach materials for The Fins United Initiative. Field work is usually in batches of “seasons” and depending what you are studying, your time in one place (be it the lab, field, or at a computer) varies.

Melissa out on a boat, on another collection trip.

Question 10: Was there anything about your career that you had to learn/do that you were not expecting?  How did you conquer it?

MM: I was definitely not expecting how isolating some of the work can be! But that’s just the nature of our work, at times. You learn to be the best company to yourself, haha.

Question 11: Do you ever get criticized on any of your work or for what you do?  How do you handle it?

MM: Of course! I’m big on journalists using the correct terminology when they cover fatal shark encounters (and will call them out on using inflammatory language such as “shark attack,” “man-eating monster,” or “terrifying killing machines”). This has gotten a lot of ire from the certain people in the public who turn their anger at the situation to me. I’ve gotten death threats and told that they wished I was the next person to die from a shark bite. At first I was really shocked by the viciousness of people but I’ve developed some thick skin over the years. If I truly am getting harassed or feel like I’m in danger, I don’t have second thoughts on reporting the person.


Question 12: Do you ever work with aquariums?  If so, in what capacity?

MM: I’ve worked with aquariums in the past as someone who helps take care of the elasmobranchs in the facility. Feeding them, mainly. You can see the one of my elasmobranchs in New Zealand on the cover of SMORE magazine.

Melissa handling a carpet shark (Cephaloscyllium isabellum) in New Zealand.

Question 13: One of my favorite things about what you do is that while you do great scientific work, at the same time you are constantly communicating with more general audiences, as well, to actively dispel lots of stigmas attached to sharks and their relatives.  What are some of the most common misconceptions that people have about sharks that you wish would disappear?

MM: My main two would be this: sharks intentionally eat people and sharks don’t get cancer. First, “rogue sharks” (a shark that has a taste for human flesh) are not real and no scientific evidence backs their existence. We are not on the menu for sharks! Secondly, there are many documented observations of sharks that have growths (possible tumors) on their bodies. They have fantastic immune systems but as susceptible diseases like cancer regardless.

Melissa holding a spiny dogfish after a collection trip for the aquarium she worked at.

Question 14: You are most famous for your work with Sharks and their relatives, rays, skates, and chimeras.  Do you have experience working with any other kinds of marine life?  What about land animals?

MM: I do! In the past I’ve been lucky enough to work with dolphins, whales, manatees, otters, and a variety of other marine life. While interning in Belize I was also in charge of a slew of jungle animals- including ocelots!

Question 15: Are there any species that you want to work with that you have not worked with before?

MM: Plenty! I would love to work with mako sharks, oceanic white tips, whale sharks, thresher sharks, more deep sea sharks… the list goes on!

Question 16: What is your favorite animal overall? (Be as specific as you need to be.)

MM: The tiger shark (Galeocerdo cuvier) is hands down my favourite animal. No competition. I’ve been face-to-snout quite with them numerous times and they are just perfect in my mind. Everything from their big eyes that watch your every move down to their uniquely shaped teeth and their gorgeous pattern on their skin… I can’t get enough of them! Tiger sharks are actually what sparked me to open my Etsy store that focuses on shark patterns- to showcase their beauty without the distraction of teeth.

 
Melissa up close and personal with a tiger shark (Galeocerdo cuvier) in the Bahamas.

Question 17: Why should preserving endangered marine life and their ecosystems be important to the everyday person?

MM: The marine ecosystem covers the majority of our planet yet we know so little about it and are destroying it! We need to remind people that their actions, especially those near the coasts, affects the ocean. And if you harm the ocean, well that affects everyone, even if those people live far from the ocean. The Gulf of Mexico dead zone (spread from fertilizer going down the Mississippi) is a good example of this!

Question 18: What can we all do to help preserve marine ecosystems?  

MM: 
1.     Eat sustainable seafood.
2.     Reduce your plastic pollution footprint (reduce, reuse, recycle).
3.     Help educate others about why the marine ecosystem is important.
4.     Donate to NGOs and other charities (or research facilities) to help support marine science research!

Melissa on the beach in her native Puerto Rico.

Question 19: What would your advice be to anyone trying to make a career in marine biology (or science in general for that matter) now?

MM: To follow your passion! You may get people in your life that tell you that you shouldn’t pursue marine biology (or science) but if that’s what fires you up then GO FOR IT. It’s your life and you should live it the way you want to, regardless of other’s opinions.
Education-wise, I suggest to many scientists to take computer programming/language classes (being well versed in R or foreign languages if great to have), make sure to take a few writing classes and to always take the required science and maths!

Question 20: What hobbies do you have? (Don’t have to be science-related.)

MM: I just moved to Australia, so my husband and I love going for hikes around the Sydney area to check out our new home! We’re excited to get a car and go on road trips, too. I’m a runner, love scuba diving, and like to cook as well. During my down time you can always find me reading.

Monday, January 15, 2018

Compsognathus: Beast of the Week

This week we will be looking at a popular, but often misunderstood dinosaur.  Let's check out Compsognathus longipes!

Compsognathus was a relatively small, meat-eating dinosaur that lived in what is now Germany, France, and possibly Portugal, during the late Jurassic period, about 150 million years ago.  From snout to tail, an adult measured almost four feet long.  The genus name, Compsognathus, translates to "delicate jaw" and the species name, longipes, translates to "long foot", both in reference to this dinosaur's anatomy.

Compsognathus longipes with Archaeopteryx chick as prey.

The first specimen of Compsognathus discovered back in the mid 1800s was only a little over a foot long, and was considered the smallest known dinosaur.  In addition, there were not many small-ish fossil dinosaurs known yet, either, so Compsognathus became sort of an oxymoron, and therefore quite popular.  It almost always would appear in books about dinosaurs for years to come as "the smallest dinosaur!" often being compared to a chicken in size.  However, during the 1970s, a larger specimen of Compsognathus was unearthed in France that was almost four feet long.  Not huge...but certainly bigger than a chicken, proving the original German specimen was only a juvenile when it died.  Thanks to many more dinosaur discoveries since then, Compsognathus was far from the smallest nonavian dinosaur, but for some reason that stigma hasn't fully shaken even today.

Compsognathus that was discovered in Germany.  This specimen was roughly the size of a small chicken, and was for many years regarded as the smallest kind of dinosaur. (not including birds)

One cool thing about Compsognathus is that we know what it was eating before it died.  Both specimens on the fossil record have the bones of lizards in their body cavities, proving this dinosaur was a meat-eater, and likely quite agile if it was catching lizards in life.  The teeth in the front of Compsognathus' mouth were straight and pointed, while the teeth lining the sides of its jaws were more flattened, and blade-like.  This would have enabled it to capture and process small prey.  Compsognathus had two relatively short arms, each equipped with two long fingers and a third shorter finger.  For a while Compsognathus was believed to have only had two fingers because of the incompleteness of the first uncovered specimen.

Thanks to well-preserved specimens of other closely related dinosaurs that preserved down-like feathers on their fossilized bodies, it is logical to assume Compsognathus also had some sort of feathering in life.  This is despite the fact that no fossils of Compsognathus, itself, provide  fossilized feathers, themselves.The kinds of feathers found on members of Compsognathus' family would have been fine and soft in life, and may not have fossilized under the conditions that Compsognathus, itself, was in.

Compsognathus skeletal mount on display at the Academy of Natural Science in Philadelphia, Pennsylvania.

During the late Jurassic, the parts of Europe that Compsognathus was native to were a chains of small islands in a shallow sea.  The islands would have been relatively dry, sandy, but also would have had inland lagoons.  Some of Compsognathus' neighbors would have included all matter of marine life, small lizards, the pterosaurs, Pterodactylus and Rhamphorhyncus, and fellow feathered dinosaur, Archaeopteryx.  Since no remains from any large land animals have been found from this habitat, it is likely these small islands could only support animals under a certain size threshold due to a lower availability of food and space.  It is very likely that Compsognathus was the top predator of its community.

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

References

Chen, P.; Dong, Z.; Zhen, S. (1998). "An exceptionally well-preserved theropod dinosaur from the Yixian Formation of China". Nature. 391 (6663): 147–152.

Seebacher, F. (2001). "A new method to calculate allometric length-mass relationships of dinosaurs". Journal of Vertebrate Paleontology. 21 (1): 51–60.  

Stromer, E., 1934, "Die Zähne des Compsognathus und Bemerkungen über das Gebiss der Theropoda", Zentralblatt für Mineralalogie, Geologie und Paläontologie, Abteilung B, Jahrgang 1934: 74–85

Therrien, F.; Henderson, D.M. (2007). "My theropod is bigger than yours...or not: estimating body size from skull length in theropods". Journal of Vertebrate Paleontology. 27 (1): 108–115.

 Zinke, J. (1998). "Small theropod teeth from the Upper Jurassic coal mine of Guimarota (Portugal)". Palaontologische Zeitschrift. 72: 179–189. doi:10.1007/bf02987825. Archived from the original on 2007-09-27.