Tuesday, July 28, 2015

Archosauriform Tooth - New Preprint

As promised, I am back with more tooth news!

My students and I just published an updated version of our preprint describing an unusual archosauriform tooth from the Chinle Formation of Comb Ridge. In this preprint we describe a small, serrated tooth that one of my student co-authors discovered as float in May of 2014. While this article is not peer-reviewed it was submitted for review last week with a few minor changes from the preprint. I caught a few things from my students I had missed before, like calling semionotiform fish tetrapods.

What is the significance of this tooth? In addition to it being the result of my high-school students' fieldwork, this rather plain-looking tooth is somewhat unusual.

MNA V10668. Image from Lopez et al., 2015. A lingual B labial C distal D mesial E apical F basal. Scale bar = 1 mm. CC BY-4.0
At first glance the tooth appears to be relatively nondescript. It is triangular in profile with a slight labial curvature (meaning the tip is deflected towards the center of the mouth). It isn't too wide at the base and is not recurved. All in all, a pretty standard tooth.

A further look at it tells a different story. When my students looked at it and compared it to other Triassic teeth they noticed several differences. It has more serrations on the distal carina than most of the other reported taxa from the Chinle. It is labiolingually compressed, much more than a phytosaur but much less than a dinosauromorph.

My prompt to the students was relatively simple; identify this tooth to the most exclusive group you can. My students spent lots of time describing and comparing MNA V10668. A couple of my students were very stressed out but came through with useful comparisons, as I mentioned above (and detail in the paper).

One thing that was not adequately done in the first draft of the manuscript was a comparison with phytosaurs. The students, including ones who didn't become authors, were either A) not very good at elucidating the similarities and differences between MNA V10668 and phytosaurs or B) didn't attempt to do so at all. This was a problem since no doubt any reviewer would immediately ask to see why we thought this tooth was different from phytosaur teeth. Now adult phytosaurs were easy to distinguish from: they are quite a bit larger than MNA V10668.

Machaeroprosopus skulls at the New Mexico Museum of Natural History. CC-BY 2.0, created by Lee Ruk. No scale is provided but the skull is certainly longer than 1 meter.
Distinguishing from juveniles created a different problem. Juvenile phytosaurs are not as well known; those that have been identified in collections are usually not mentioned or poorly described in the literature. Fortunately the MNA has two juvenile phytosaurs in their collections that helped me address that problem: PEFO 13890/MNA V1789, a paired set of juvenile premaxillae and MNA V3601, a terminal right dentary. Both have teeth and alveoli that are the right size to address the question of whether MNA V10668 came from a phytosaur.

Juvenile phytosaur jaws. Top: PEFO 13890/MNA V1789, Macheroprosopus zunii premaxillae in A) ventral view. Bottom: MNA V3601 right dentary in B) lateral C) dorsal views. Scale bar = 1 cm. From Lopez et al. (2015), CC-BY 4.0
While these are not complete sets of dentition you can get a good idea as to what the teeth of juvenile phytosaurs would have looked like. Generally the bases were circular, not laterally compressed like MNA V10668. The teeth that are present in these specimens are all conical. Some, in MNA V3601, lack serrations. This allows us to feel reasonably certain that MNA V10668 doesn't come from a juvenile phytosaur. Our conclusions would be more solid if we had more preserved dentition from the posterior portion of the jaw, especially since this is the part of adult jaws that have teeth that look more like our specimen. None-the-less it is pretty clear that the juvenile jaws are less specialized than adults in their respective tooth positions - it seems reasonable to suggest that posterior teeth are also conical. This would also be in line with some modern archosaurs and their different juvenile/adult diets. Having conical teeth would help juvenile phytosaurs capture insects and other small prey while adults exhibit heterodonty, allowing them to efficiently process large prey items.

In any case, it appears pretty clear to my students (and myself) that MNA V10668 represents something other than a phytosaur. For that matter, it doesn't correspond to any other identified taxon from the Chinle Formation. Is it unique enough to name a new taxon off of? I don't think so. I admit this is a subjective call, but since the concept of a species in a paleontological sense is subjective anyway I don't see a problem there. In any case it is not like any other identified animal tooth from the Triassic of the southwest.

Lopez A, St. Aude I, Alderete D, Alvarez D, Aultman H, Busch D, Bustamante R, Cirks L, Lopez M, Moncada A, Ortega E, Verdugo C, Gay RJ. (2015An unusual archosauriform tooth increases known tetrapod diversity in the lower Chinle Formation (Late Triassic) of southeastern UtahPeerJ PrePrints3:e1539 

Tuesday, July 21, 2015

My Students Need Your Help

I'm going to cut right to the point here (in case the title didn't give it away). My students need your help. I know I am the goofy tooth blogger who writes about "Indominus rex" and little tiny teeth from the Triassic but the plain fact is that those little tiny teeth don't find themselves. In fact they like to stay hidden, the sneaky little fellows. My high school students in my paleontology program find the majority of them.

In case you didn't read my introduction post, I teach at Mission Heights Preparatory High School and run the nation's only paleontology program at a public high school. I am pretty dang proud of it and my students. We have been doing this since March of 2014 and we already have one publication with one of my students, another pre-print ready to go to review with student lead authors, and a student-led abstract accepted for presentation at the 75th Annual Society of Vertebrate Paleontology Annual Meeting in Dallas this year. All very exciting stuff and it has all been predicated on the field work we have been doing in the Late Triassic Chinle Formation at Comb Ridge, Utah.

In order to do this fieldwork, we have been relying on two things: rented vehicles, paid for by student fees and my personal truck. These two elements have allowed us to access field sites and bring back fossils to MHP but they have their drawbacks. Student fees create a burden on our students, especially in our low-income, rural community that we serve. Some of these students are classified as homeless. Most of our students are on free-and-reduced lunch, meaning that their annual family income qualifies them for government-provided school lunches. These are generally not kids who can afford a $75 fee to rent vehicles, get gas, and buy food. Several promising young scientists had to miss out on trips (and have since moved on from science all together) because their family lacked the means to support them in pursuing our fieldwork. This is a huge concern for me! I have trimmed by budget as much as possible but with the huge cost of renting vehicles for multiple days I cannot get my per-person cost down any lower for our regular spring fieldwork trips. If we care about having scientists accurately represent our society we should be concerned that low income students are dropping out of science because they feel they cannot participate.

The second drawback is in relation to my personal vehicle. It is a 2004 Ford Explorer Sport Trac. It is a great vehicle and has served me well but it has 186,000 miles on it. I was working at a quarry in Utah with the Natural History Museum of Los Angeles County last week and my truck malfunctioned. Now the fix was easy and relatively inexpensive, and since the crew had multiple vehicles they were not out of work while my truck was in the shop. My truck, however, was out of commission for a day and a half. On a multi-week trip this is not a huge deal but when we are working at Comb Ridge we are typically out for only two days. That is a huge blow! I was lucky enough to have my truck break down in Moab - that would certainly not happen with our Comb Ridge work since we rarely go into town. The nearest town, Bluff, also does not have a full-service auto repair facility and parts stores. In addition the NHMLA had multiple field vehicles available to get in and out of locations and haul gear. For our program we use my truck to haul all the gear and rented vehicles to haul all the students. If we had a breakdown with my truck in the field with students it could be a real disaster with no easy fix.

That is why I am asking for help. I am trying to raise $8,000 for a field vehicle for MHP. We have raised a bit over 1/8th of the total goal but we have a long way to go. I am hoping that if you care about students, paleontology, getting students involved in paleontology, or just creating a more science-literate society you will consider donating to our fundraiser. All money raised will go directly to the cost of a field vehicle or, if we are unable to purchase one, into renting field vehicles until the funds are depleted.

If you like learning about teeth, that is where the teeth come from. And I have more tooth posts coming up soon!

Saturday, July 11, 2015

Bigger. Badder. More teeth?

Okay, show of hands: who has seen Jurassic World? If you haven't seen it I promise this article won't be spoiler-filled. I promise I won't discuss plot points. In fact, I won't discuss anything that you can't see in the trailers. What I will discuss, though, is teeth!

So if you have seen any of the promotional material for Jurassic World you know that the scientists have created a "genetically modified hybrid" named "Indominus rex." Leaving aside issues about genetic modification and dinosaurs in the Jurassic Park universe, one of the tag lines for this new animal was "Bigger. Louder. More teeth."

Jurassic World promotional image. Image (C) Universal Studios.

Fair enough. From the trailers you know that Dr. Wu says, "She was designed to be...bigger than the T. rex." This also makes sense -Tyrannosaurus is obviously a super-cool animal and would be a big draw at an amusement park like Jurassic World. If you were setting out to make a world-beating attraction then you could do worse than to choose T. rex. While other theropods may have been larger, it is certainly the most charismatic and probably the most well known. So when they are saying that "Indominus" is bigger, louder, and has more teeth they are probably comparing her to Tyrannosaurus.

There's just one problem with that. "Indominus" doesn't have more teeth that T. rex.

Skulls of Tarbosaurus (A) and Tyrannosaurus (B) by Jørn H. Hurum and Karol Sabath [CC BY 2.0], via Wikimedia Commons
As you can see, Tyrannosaurus has a combined total of 15 premaxillary and maxillary teeth. Now let's take a look at some of the promotional images and trailer stills from Jurassic World.

All images (C) Universal Studios.
How many teeth do you see? I count between nine to 11, depending on which motion-blurred image I'm using as reference. This is a situation different from, say David Peters, because in the case of "Indominus" there is no actual skull to do tooth counts with. Unfortunately I have to make do with images.
Here is Chris Pratt under a vehicle in a still taken from a Jurassic World trailer. I have numbered the teeth in the upper jaw (that I can make out), though the depth of field and motion blur make it difficult to be certain on their ID.
So last time I checked 9 < 15. Even 11 < 15. The big, scary "Indominus" has fewer teeth than a Tyrannosaurus. Maybe they were referring to ornithomimosaurs when they were making their comparison? Who can say.

Does this really matter? No, not really. Me nit-picking the strange, croc-toothed creation from Jurassic World doesn't change anything in the grand scheme of things. I just found it amusing that one of their promo points is in fact wrong. It doesn't impact how I feel about the movie, which I enjoyed. It shouldn't change how you feel about the movie.

Want more Jurassic World teeth analysis? Join me next time here at the Prehistoric Pub when I try to figure out what the heck is going on with the "Indominus" dentition!

Tuesday, July 7, 2015

A Toothy Issue

I am going to talk about teeth today. When I first knew I was going to get into paleontology I didn't think I would every really study teeth. I mean, teeth are neat and everything but I wanted to study dinosaurs! Dinosaurs, especially when I was younger, were mainly known for having relatively simple and easily-identifiable teeth that didn't tell us much besides diet. The only people who studied teeth were mammal paleontologists (which I foolishly looked down upon in my middle and high school years).

Even as I progressed through college I didn't pay much attention to teeth. Sure there were some odd teeth known from the Triassic Period, like Revueltosaurus and Tecovasaurus, but they were rare and the exception to the rule. I figured that they provided only marginal information on the ecosystem and that the major components were well known and understood - things like phytosaursmetoposaursaetosaurs, and rare dinosaurs like Coelophysis. Well it turns out, unsurprisingly, that this view is naive and wrong.

Some of this change has come about from the work of Andy Heckert in the early years of this century. Although his treatise on Chinle microvertebrates is somewhat out of date now (it was published by the New Mexico Museum of Natural History and Science in 2004) it helped establish that the diversity of animals living in western North America was much higher during the Triassic Period than people had previously suspected. In addition to naming new taxa like KrzyzanowskisaurusProtecovasaurusand Crosbysaurus, his PhD work showed many new tooth types from the Chinle Formation and Dockum Group that had never been reported in the scientific literature!

Our work at Comb Ridge has focused on teeth. This is not because we set out to find lots of teeth. As with most things in paleontology you focus on what you find. At Comb Ridge we haven't found phytosaur skulls and troves of fossil fish like we do further north. We haven't found aetosaurs like in Arizona or mass graves of dinosaurs like in New Mexico. Instead we are finding teeth. Lots and lots of teeth. So many teeth that one locality, The Hills Have Teeth, may be the most productive microfossil site in Utah - it is certainly the most productive microsite in the Chinle of Utah. We have a dozen species represented, possibly more, from this one hill and they are all known from their teeth. So let's have a brief overview of tooth anatomy and terms so that it doesn't seem like I'm speaking gibberish in future posts.
Handy guide for some of the most common tooth terms I made based on an image from Lopez et al. (2015). Scale bar = 1 mm. CC-BY 4.0
List of Dental Anatomical Terms and Definitions
  • Apex - the "top" or tip of a tooth; the portion furthest away from the gumline.
  • Apical - a directional term, referring to things towards the apex.
  • Asymmetrical - a tooth, viewed from the apex, that does not have the same profile on the lip-side as it does on the tongue-side.
  • Base - the "bottom" of the tooth; the portion of the tooth at the gumline.
  • Basal - a directional term, referring to things towards the gumline.
  • Carina - a distinct ridge or edge, usually found along the leading or trailing edge of the tooth.
  • Cingulum - a ridge, "waist", or "belt" of thickened enamel running around the tooth near the gumline.
  • Circular - refers to a tooth that is circular in outline when viewed from the apex.
  • Conical - a tooth that when viewed from the side has a roughly cone-shaped or pyramidal outline.
  • Crown - the portion of the tooth from the gumline to the tip. What most people think of when they use the word "tooth."
  • Denticles - triangular or angled protrusions along an edge used for cutting food. Can be angled towards the apex or facing perpendicular to the crown height. In some species these can be subdivided into smaller denticles.
  • Dentine - the tough inner material that makes up most of a tooth. Very hard but not shiny.
  • Distal - the part of the tooth facing the back of the mouth. In older literature this is sometimes referred to as "posterior."
  • Enamel - the tough, shiny, outer surface of a tooth. A very hard material!
  • Infolding - used to be commonly referred to as "labyrinthodont", which means "maze tooth." These are places on the tooth where the enamel is folded in towards the center of the tooth. It appears wrinkled.
  • Labial - the side or portion of the tooth that faces the outside of the mouth. Labial literally means "lips."
  • Laterally compressed - refers to a tooth that is much thinner "side to side" than it is "front to back" when viewed from the apex.
  • Lingual - the side or portion of the tooth that faces the inside of the mouth. Lingual literally means "tongue."
  • Mesial -  - the part of the tooth facing the front of the mouth. In older literature this is sometimes referred to as "anterior."
  • Occlusal - the surface, face, or point of the tooth that would rub against ("occlude") the opposite tooth from the opposite jaw. Sometimes used in place of apical when referring to a viewing angle.
  • Recurved - a tooth that, when viewed from the side, has the back (distal) side curved inward, so that the edge looks like a half-moon.
  • Resorption pit - a pit on the base of a tooth, showing where bone and dentine were reabsorbed by the animal to allow the tooth to be shed.
  • Root - in animals with teeth set into sockets, the root is the dentine that extends below the gumline into the jaw to anchor the tooth.
  • Serrations - like on a steak knife, these are small notches on the edge of a tooth for cutting or slicing food.
Okay, so there are a number of terms there but I think I've given the definitions in terms that aren't too hard to follow for the average person. Let me show a few examples of teeth so I can sort of show how these terms are used "in the real world."

Crosbysaurus tooth. Scale distance = 1 mm.
The above picture is of part of a Crosbysaurus tooth from one of our sites at Comb Ridge. It shows denticles, the pointed cutting parts on the distal edge (or carina) of the tooth. Each of the pyramid-shaped structures has smaller bumps on them - these are the accessory denticles. This picture is in labial view.

Crosbysaurus tooth. Scale distance = 1 mm.
Here is another view of the same tooth. Here we are looking at the tooth in mesial view with the apex on the right and the base on the left. You can see a resorption pit at the base - it looks like the tooth is hollow. You can notice that this tooth is laterally compressed - it is much narrower than it is tall.

Archosauriform tooth. Scale distance = 1 mm.
Last example. Here is an archosauriform tooth in basal view. The front of the mouth, or mesial side, would be towards the right while the back of the mouth, or distal side, is to the left. You can see in this view that the tooth is asymmetrical - the labial and lingual sides are not equal. This picture also gives a decent view of the resorption pit located in the middle of the base here. That tells us that this is a shed tooth crown.

Thanks for making it through this! I know there were a lot of terms but I promise they will come in handy for many of my future posts. And now you can impress your dentist with your knowledge of dental terminology! The paleontology of teeth (Odontology) is not just for mammal paleontologists. All of this work with microfossils and Triassic teeth has certainly given me a new appreciation of how important these little things can be and what they can tell us about an ecosystem. Just what specifically can they tell us? That sounds like another blog post in its own right.

Tap Talk Tuesday with Dr. Phillip Manning!

It's a rainy day out in the field, so while I wait for things to dry up around here, I thought I'd post an an interview.  This interview however was from way back in 2011. The questions I asked pretty much set the standard for the questions I still ask today when interviewing.  I have tweaked them over the years, but I came up with the following series of questions because it was what I wanted to know as a kid.  The interviews I've given over the years have been wonderful. I appreciate the time that everyone has set aside to do them for me and I'm always thankful for the opportunity.  OK, let's see what it's doing outside.  I will report more soon from the field, but in the meantime, enjoy one of my first interviews below.  Until later later everyone!
For those of you who may not know, Dr. Phillip Manning is an internationally renowned paleontologist, fossil hunter and writer.  He has taught vertebrate paleontology and evolution at the Universities of Liverpool and Manchester and currently heads the Paleontology Research Group in the School of Earth, Atmospheric and Environmental Sciences (SEAES) at the University of Manchester.  Dr. Manning has published papers on many diverse subjects, including dinosaur tracks, theropod biomechanics, arthropod paleontology, vertebrate locomotion, and the evolution of flight in birds.  Along with his long list of many accomplishments that continues to grow, Dr. Manning has also worked with National Geographic on an amazing series called Jurassic CSI.  
Dr. Manning has always been a hero of mine.  On May 17, 2011, I finally got a chance to meet the good doctor in person at a lecture being given by Dr. Jack R. Horner at The Academy of Natural Sciences in Philadelphia, PA.  It was an absolute honor to meet such an educated gentleman in the field of paleontology.  I only wish that I had my copy of Grave Secrets of Dinosaurs by Dr. Manning for him to autograph.  I have fond memories of picking up this book when it first came out and never putting it down.  I highly recommend picking it up.  
Upon meeting Dr. Manning, I was a nervous wreck, but his humbleness will quickly calm you down.  He is a brilliant man, but also very down to earth.  Passionate about his work and someone I admire greatly. I appreciate him taking the time to hangout and talk with me that night.  I learned a lot.  Not long after that awesome night of meeting Dr. Manning, we exchanged e-mails.  I asked if he would be interested in doing an interview for my website and he graciously said yes!  So, without further ado ladies and gentlemen, I give you our interview.  Special thanks Dr. Phillip Manning. 

You are one of my heroes in the field of paleontology.  Who did you admire growing up?

I watched Sir David Attenborough on TV whenever I could. The series 'Life on Earth' was quite life-changing for me...I realised we lived in a big world. I have to point out, I was about 7 years old, living in a village in rural Somerset...quite the middle of no-where, but beautiful! I have been lucky enough to meet and work with Sir David on a BBC series a few years ago and he was 'the real deal', a splendid gentlemen and a scholar.

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

When I first moved to Somerset aged about 6 or 7, I discovered I had Lower Jurassic (Lias) fossil in my own garden. That's when it started proper. However when I was aged 5, i visited the British Museum of Natural History in London, now called the Natural History Museum. Stood before me was the mount of Andrew Carnegie's Diplodocus...wow...that also had a major 96 feet impact on a very small child.

What was your favorite dinosaur growing up?  What dinosaur is your favorite now?

I had two favourites as a child, and yes...you can probably guess them both...Triceratops and T. rex. I am sooooooo grateful to have been able to find both these dinosaurs in the Hell Creek Formation now. In recent years I have grown very fond of Archaeopteryx....and hope to publish another paper on this beastie soon!

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

My advice is simple, choose the subjects which you most enjoy, as it will be these in which you have most chance to excel. There is no single route into palaeontology, which I know is some folks chosen career path. Many of my palaeo colleagues come from both arts and science background...like myself, others are pure science and some are pure art. The key here, is I took a path that was dictated by no one. If there is a 1+1=2 path to palaeo, I'm afraid i do not know it, as thankfully we are all very different. Darwin made a point of celebrating variation within a single species :-) and we are no exception to this rule. To put it another way, there is no 'one size fits all' route for me to advise any budding bone-hunters out there. This is probably a good thing. 
However, If a person has a specific university course in mind, then I urge them to look at the entry requirements now...as this will be an affective gatekeeper after High School. If you have your heart set on being a palaeontologist, you have already taken the most important step. There are few places you can learn passion for a subject, as that is something only a few are gifted with at an early age. It seems that many such folks are also 'one' of the lucky ones.

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?

This is a very tough question, as here I should put-on my 'professor hat' and spout the virtues University and grad school...however, like I said before...we are all very different. Some folks are terrible scientists and do not enjoy the rigours of academia, this is fine...it would be a strange world if we all ended up as 'Dr'. Some of the best field palaeontologists and great thinkers of the field did not have a formal college education. This is fine, many 'trained' academics have a tough time keeping up with 'amateur' enthusiasts. The 9 or 10 years it takes to scratch your way through 1st degree, masters and PhD can and usually is, very tough. I did it, but many do not complete their studies. I have to admit, that doing my MSc and PhD was certainly the hardest things I have done in my life.

What was or is your favorite research project?  What are some of your current projects?

Some of my favourite projects have involved digging-up dinosaurs on the Isle of Wight. I was lucky enough to help excavate the then un-named, Neovenator from the Lower Cretaceous back in 1989. It was more of a mud-bath than an excavation, as the Wessex Formation from whence it came is a tad sticky. This reminds me of my favourite joke! 'What's brown and sticky?.................a stick :-).....sorry!! My most recent projects have been involved with working on the Stanford Synchrotron, a particle accelerator than can generate super-intense x-rays that allows us to analyse the chemistry of fossils. We have mapped 120 million year old pigment patterns in Chinese fossil birds and even gotten a whiff of pigment in the famous Archaeopteryx....this work continues.

Jurassic Park was the movie I remember as a kid that fueled my passion for dinosaurs.  What was your most memorable movie?

I have to admit, Jurassic Park was quite a fun romp. I watched the UK premiere, as was studying for my Masters at the University of Manchester at the time. However, my favourite film...is not a palaeo-one, but Lord of the Rings....which I am sure will be overtaken by The Hobbit when that is released.

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

That's another tough question, as I was lucky enough to be taught Geology at school, so had an early intro to the field. However, when I was about about 11 years old I visited the local Museum in the ancient city of Wells (Somerset). I had some fossils that I needed identifying, as I was sure I had found a Lower Jurassic vertebra from a marine reptile....which it turned-out I had! Well's Museum is a strange little place (seemed huge to me then) and the Curator had an apartment in the Museum (strange, funny, odd, but what a great job!). I remember knocking on his door and then sitting down at a small table with my fossils finds. I honestly can't remember if I was worried or not...I think that happens when your much older. Most kids are fearless...I could do with some of that 'fearless' every now and then in my field of work.

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

Dinosaurs are the ultimate 'safe' monsters. They are well and truly extinct, but 'monsters they be'...The sheer size and weirdness of these beasties never ceases to gob-smack me every time I see a new specimen.

What is your favorite time period?

The years from 1800 to 1860. This was an age of discovery. Here the world changed forever, from an Earth that was perceived to be 6000 years old and created by the hand of God, to an Earth of immense age inhabited by species that have evolved through the natural selective processes of 'decent with modification; into the 'endless forms most beautiful' to paraphrase good old Darwin. The foundations of 'modern geology' and the underpinning of palaeontology was also achieved in this period of time...it must have been a very exciting intellectual landscape in which to romp.

The time span in which the dinosaurs lived in was huge.  How do paleontologists remember all that information from such a vast era?  Do paleontologist focus on one particular subject?

We do not remember, those who say they do....are being economic. We use books, like anyone else, to brush-up on our knowledge as and when required. With the advent of the internet, we can now fact-check things and publish papers ever faster than before...which can be a pain in the rear sometimes, as many papers that should not be published...are!

Project Dryptosaurus has been my passion for as long as I could remember.  Why do you feel Dryptosaurus is such an important dinosaur?  

Dryptosaurus is a curious beastie in many ways. I have to be honest, I prefer Cope's name Laelaps, but this is sadly no longer valid :-( We have the lovely Tom Holtz to blame for that...thanks Tom ;-) However, we can thank Tom for bringing your beastie into the hallowed realm of the tyrannosaurs...woof! Any late Cretaceous large theropod excites folks...especially if they are the kin of T. rex. Here we have one of the worlds oldest discovered big predators from the Late Cretaceous, slap bang near some of the biggest human population centres in North America...we should know more about Dryptosaurus than T. rex!

Works Cited:

Monday, July 6, 2015

'Tis the season for digging Triassic beasts! Part 1

Today we set out for the badlands of New Mexico and had a rather productive first day.  It was a scenic drive and as you get further out, civilization begins to disappear in your rear view mirror.  On our way, we enjoyed a wonderful geology lesson via Dr. Axel and also fancied our new field vehicle!  Yup, you heard right, we now have a new truck.  Complete with air conditioning!  Our last truck was very old and has been put out to pasture.  I will miss that suburban.  She was a good ride and I will always have fond memories of her.
Our old truck.
The new Beast!
On our way into the field.
I was up at 5AM and waited to get picked up by the good doctor.  He was there right on the tick as always and soon we were on our way to the museum to load up.  There we would meet up with the others.  Loading up the trucks is the first important thing we need to do.  You definitely don't want to forget anything or you will be up a Triassic creek without a paddle!
Getting the lab ready the night before for when we return.
The first day in the field is usually comprised of uncovering the site and getting organized.  Sometimes you have specimens in the ground that could not be taken out during the last class or field season.  That being the case, these finds need to be tended to ASAP in order to get them out safe.  After a brief lecture, we set out around the site to secure any finds that were left behind.  Specimens left behind are wrapped in plaster casts or covered with tarps to keep them safe from the harsh elements of the desert.  Along with uncovering the finds, we all have the pleasure of unloading the equipment we will be using for the time we are at the site.
Tarp covering important specimens from last field class.
The first day is mostly about prepping the site, but just by prospecting around, you can see evidence of what this area once looked like.  Fish!  Yes, fish scales, fish parts, and lots of fish fossils liter the quarry floor.  They tend to look exploded, but overall they are very beautiful to look at.  They are a perfect fossil in which to gauge what the area must of been like during the Late Triassic.
Fish fossil.  Notice the beautiful scales.
At our locality, fossils we find are sometimes found on the surface.  Trace fossils are often seen in the area.  Gretchen, our museum director, found a gorgeous example.  A trace fossil is an imprint of a specimen.  Dinosaur tracks are good examples of trace fossils.  Plants, insects, and other types of organisms can leave fossilized imprints for us to find.  Below are a few examples of burrows found in the area.  These are trace fossils that have become very prevalent in recent field seasons.
Burrows from an overturned piece of mud stone.
Gorgeous piece found by Gretchen.
You can also find bone material out on the surface at times.  While unwrapping a site we call Bravo West, Gretchen our museum director found a small bone.  Finds that are found out and about are sometimes labeled as a "Float."  Float meaning we don't know for sure where the fossil might have come from.  A good example would be a couple of turtle shell pieces I found while prospecting about.  Way above our dig site is a formation from the Pleistocene. In seasons past, large turtle shells have been found at the base of the cliff side.  Now, where is the source of these pieces?  That is yet to be discovered!

Small bone found by Gretchen while uncovering Bravo West.
Turtle shell pieces that were transported down a steep hill.
Out in the field, you sometimes encounter wildlife.  While it is rare to spot something like a wild boar or mountain lion, little creatures scamper about.  I was lucky enough to get up, close, and personal with a Collard Lizard.  He was very calm as I approached him.  Probably doesn't get many Jersey Boys bothering him, so he let my presence slide.  No spiders thank the maker!  I am terrified of Tarantulas.  Hopefully I don't encounter any this field season.

I really enjoyed our first day in the field.  Always something new and exciting to learn. I had a productive first day and so did our team!  We have a great group this year as always and we all made fantastic discoveries.  All this on the first day!  Not far from where I am currently working, the previous field team uncovered a phytosaur mandible!  It will take some time to get out, but it looks sweet!  The first thing I uncovered was a tooth.  Right under it was a vertebrae.  These two items remain as it is pouring rain outside.  The weather outside is pretty nasty at the moment.  In all my years coming out here, I have never seen the weeds so high from all the rain.  Everything I found was located several centimeters below the quarry floor.  My best find of the day was a piece of a phytosaur skull!  A decent size too!  We shall see what tomorrow brings.  
Tooth I found.
Looking good, but not the smartest field gear to wear out in the desert. This was during the cool morning.
I mentioned yesterday that I would be posting live from the field.  Well, by live I mean whenever I get a chance ha ha.  As things progress, I will be limited on time, but I will post whenever I can from out here!  Until next time, have a great night everyone.
Fossil of a fresh water clam Dr. Axel found while examining my phytosaur skull.

Sunday, July 5, 2015

Hello and Introduction

Howdy all!
I'm new to the team here at the Prehistoric Pub and to blogging in general. I figured I would introduce myself to you all and let you get to know me!
I'm Rob Gay and I am a paleontologist in Arizona. Ever since I was a kid I have loved dinosaurs and other prehistoric wildlife and knew that this is what I wanted to be. Flash forward to the present and here I am - living the dream as it were.

Here's me, contemplating the dream.

My research has focused on the Late Triassic and Early Jurassic of the Colorado Plateau (you can look at some of my publications here). I am particularly interested in how the terrestrial faunas of what is now the American Southwest were structured 50 million years after the Permo-Triassic extinction (the largest in the history of the world) and how this structure changed and adapted to the "new world" of the Jurassic after the Triassic-Jurassic extinction.

I am currently engaged in several projects related to this overall line of research. I am doing a study on collections biases in the Kayenta Formation to see how our view of this ecosystem may be skewed. This may in turn impact our understanding of how these ecosystems actually functioned. This might seem a minor point but if we want to see how biological systems recover from extinction then we need to know what the systems actually looked like and how they functioned.

I also have been working for several years now in the Chinle Formation of southeastern Utah, both with a team from the St. George Dinosaur Discovery Site at Johnson Farm and the Natural History Museum, as well as with a team from my high school paleontology program - the only one at a public school in the country. The Chinle Formation is well known in Arizona (at the Petrified Forest) and in New Mexico (at places like Ghost Ranch) for the amazing variety of life from the dawn of the age of dinosaurs. Utah is also well known for its prehistoric life, but the Late Triassic Period has been rather underrepresented. Between work in Lisbon Valley and at Comb Ridge we are starting to piece together just what this area looked like 203 million years ago. We have identified new and unusual types of reptiles as well as documenting the presence of a plant-eating crocodile-like reptile known as Crosbysaurus. In the case of Crosbysaurus, this is the first time it has been reported from the state of Utah.
The tooth of Crosbysaurus from Comb Ridge. Abbreviations: Ap, apex; DD, distal denticles; MD, mesial denticles; RP, resorption pit. Scale = 1 mm. Image is from Gay and St. Aude (2015), CC-BY 4.0
I am very pleased with our Comb Ridge work in general because it is all with my high school students. They get a chance to experience real-world hands-on science by being involved in all aspects of vertebrate paleontology - including publication! I know I will blog a lot more about this in the future so I won't belabor it here!

In addition to all of my paleontology work I am also a dog-parent of two awesome beasts. I like playing video games. I enjoy craft beers; I am on a saison kick right now due to it being summer, but IPAs are my thing generally. I'm looking forward to letting more people know about my students' research, my research, and generally interacting with folks on here. Cheers!

Back to the Triassic!

My last flight was very empty and reminded me of a Jurassic Park III movie moment.
Yesterday began my second trip of the summer field season.  I am currently writing you from New Mexico where I will be starting another Triassic adventure. Tonight I will be meeting with the field team and going over preparations for tomorrow at which time we will be heading out early in the morning.  Our field class will be exploring an area called the Redonda Formation which dates back around 200 million years ago (the late Triassic Period).  The Triassic Period comes before the Jurassic and is filled with all sorts of interesting prehistoric beasts.  The unique place we will be digging contains specimens that existed just before a mass extinction wiped them out.  This mass extinction eventually gave rise to the dinosaurs which flourished for millions of years after.  I am very excited to be here and have been visiting this site with my professor, mentor, and good friend Dr. Axel Hungerbuehler for many years.  One of my first treks to this site was mind blowing and can be read about here!
Field work being done during 2013 season.
This field season should be a grand one!  For the first time, I will be posting live from the field. I am limited as to what I can post as always, but I will do what I can to take you along with me.  Over the years, I have accumulated 1,000s of photos, videos, and documentation.  One of the questions I get a lot is "Gary, how come you don't show anything?"  Some things can not be shown on social media.  The reason(s) being is because a lot of what we do is still in research.  Not to mention it is also important to respect the land we work on and to protect it from the public.  My field work is not volunteer and involves working with academia.  That being said, we still have a lot of fun!
I get plastered during the 2013 field season.  
Field work can be a lot of fun, but the "work" end of it for sure holds up to its name.  If you click here, you can read an example from our 2011 field season.  OK, I'm off to a lecture about our field studies, but tune in tomorrow for a post about our first day's work.  As an added bonus to my recent adventure out west, I found out today that I was featured in a newspaper article back home!  It is about blockbuster movies and opening weekends.  I simply give my take on the opening of Jurassic World from an entertainment perspective.  Click here to read!