Sunday, September 13, 2015

Dr. Thomas Holtz is my George Clooney.

When people ask me what I would do if I met this or that celebrity, I always say the same.  "I don't get starstruck." I really don't.  Being a bartender for so many years in popular spots, I have met my fair share of celebrities.  However, believe it or not, I get more giddy meeting amazing people in the field of science.  These celebrities are rockstars in my book.  Not only are they cool, but they inspire future generations with awesomeness.  Dr. Thomas Holtz is my George Clooney.  Why George Clooney Gary?  Well, just like George Clooney screams Hollywood, Dr. Holtz screams science and paleontology. The world needs more celebrities in the field of education.  Dr. Holtz is one of those celebrities.

Hats off to you Dr. Holtz and Happy Birthday.  Thank you for being an inspiration to us all.  I haven't posted in a great while, so I thought what better way to clean off the rust than to honor a great paleontologist.  I took the summer off to work hard, venture off on two field classes, and try to relax before going into another year of classes.  Special thank you to Lisa Buckley and Robert Gay for contributing to this site.  You are good friends and this site is yours also.  The pub is about sharing science and promoting good friends, so anything I can do, I do my best to help others.

P.S.  My son is a big fan of Dr. Holtz and not long ago made a character of him in Lego's video game Jurassic World along with others.  Click here to see!  Thought I'd share it again if you haven't seen it.  It is truly an epic creation.

Wednesday, September 9, 2015

Fieldwork Flail: The Ups and Downs of Being Out and About

Hello, Dear Readers!

Well, the thesis is off to the committee (eep!), so now I get to digitally dust off the blog and leave the academic hermitage that is writing thesis chapters! I've been figuratively chained to the office for most of the summer. While this was a self-imposed office banishment, having to stay indoors and write during the summer when every fiber of my being was screaming to be outdoors doing fieldwork wore on me. Needless to say, once the writing was done, I jumped at the opportunity to visit one of my favorite neoichnology sites before all the shorebirds abandoned us to the cold weather (thanks, birds). The site is a couple of hours drive from the museum and great for (long) day trip fieldwork.

What follows is a mixed bag of success and frustration: in short, it's the typical field story. 

I arranged with our summer field tech, Linda, to pick her up at 6am. I went to bed early, as I'd be up before the sun to put the finishing touches on my neoichnology field gear. Thanks to some horrid reaction to something I ate, I did not get to sleep until 2am. As I finally drifted off to sleep I thought "Oh, this trip is starting out well..."

The alarm blares off at 5am. I will be honest with you: I am not a morning person, even when I've had a decent night's sleep. "Good" is not paired with "morning" in my vocabulary. Our museum staff (morning people, the whole lot of them) take great delight in being all chipper around me when I first enter the building. The walking dead have more life in them than I do on waking. Several cups of tea infused me with what passes as life, I picked up Linda, we loaded the last of the gear into the field truck, and left town for a pleasantly uneventful drive to the site.

Oh, sorry. I slipped into telling fiction. Back to reality.

We were driving down the highway, which is pleasantly empty at this time of the morning. This means that I'm not ticking off the drivers who want to do 100-120km/hr by driving the speed limit (90km/hr). Given the driving habits of the region and the fact that we are smack dab in the middle of the BC wilderness, there are a lot of black tire marks on the highway. I didn't think anything of that new black mark on the road...until I was close enough to see that it had thickness. I slowed and swerved around whatever it was...


My foot left the gas immediately. We slowed to a crawl. This let me know that a) my tire(s) were still attached to the truck, and b) the axles (if damaged) would last long enough to get us to a safe shoulder. We crept along the road until we found a turn-off to a gravel road, engaged the hazards, and stepped out to survey the damage.

The flattest of all tires.

Important Field Tip #1: Know how to change the tires on your field vehicle. Don't just assume that you know how to change a tire - actually practice on your field vehicle before you set off on your adventures. Everyone on your field crew needs to practice being the lead on changing a tire. Even though we were right on the highway, we had no cell service and the satellite phone was being twitchy, so there would be no calling BCAAA.

Fortunately for me and Linda, while we had not been the leads on changing a tire, we knew enough from several assists how to do it. The most troublesome part of the process was lowering the bloody spare from under the vehicle because we couldn't find the thrice-damned attachment for the jack that fits into the decent mechanism. Which leads me to...

Important Field Tip #2: Keep all of your jack attachments in one area, even if they are small. It took longer than it should have to locate the proper attachment, which was helpfully located in the glove compartment. Once located, we were off to the races, so to speak. During the process we also encountered...

Important Field Tip #3: People are jerks. Don't trust that they will bother to stop, slow down, or even move their vehicle as they roar past you at 110km/hr on a relatively narrow highway. Out of the seven vehicles that drove past, not one even slowed down. This was all well and good - we didn't need help (and we didn't want the hassle of trying to tell someone that the damsels in distress actually could change a tire all by our little selves), but the gravel and dust being whipped at us from speeding trucks got old.

The tire change went smoothly. Once the tire was off...
we could see the extent of the damage. Whatever the tire had hit, it went right through. There would be no patching this tire. That tire wasn't just damaged: it was cancelled.
Linda shows us the extent of the damage.
That was Adventure #1. We decided that we deserved to stop at Tim Horton's before continuing on to the site. We also made a note of our location, because on the way back we planned to find the wretched thing in the road that thrashed the tire.

We made it to the parking area of the field site without any incident. Accessing the neoichnology site requires crossing a river. Usually the river is gentle and shallow enough at this location to cross without too much difficulty. However, recent rains had given the river a bit of vigor and depth. Each of us had a cumbersome load to pack across the river (plaster, mixing buckets, cameras, personal gear), and the local river bed flora add a nice element of slime to the bouldery river bed. Crossing would prove to be tricky.

We found a spot that looked promising, and started across. A combination of bulky gear, slimy boulders, and a slight misstep sent me flailing into the river.


All I remember going in was thinking "S**t, the camera!" and holding that aloft with my right hand while my left hand let go of the bucket (which Linda retrieved before it floated off on its own adventure) and broke my fall. This area was deep enough that I didn't break my fall before going almost completely under the water - I think the top of my head was still dry - but the palm of my left hand took the full force of my fall as it hit boulders and gravel. Needless to say, there was a little bit of damage.
It's only a flesh wound...I hope.
I carry a first aid kit with me, but there was very little I could do at this point that couldn't wait until I reached civilization. Sure, I could have dug around in my hand to remove bits of embedded gravel, but nice cushiony blisters formed around the impact sites, so I knew where the offending material was located. What worried me more was the sharp ache deep in my first metacarpal - did I break or crack it? I could still move it, albeit with some discomfort, so I figured we had come too far to give up on the chance of shorebird traces.

We finally crossed the river, and I changed into more-or-less dry clothes. We had arrived!

This area is dominated by Canada Goose tracks, and the fine-grained sediment captured their trampling nicely.
Canada Goose trample surface.
With the Canada Goose tracks were smaller anseriform (duck) footprints: they have a different overall shape than Canada Goose tracks, so we knew they weren't young geese.

Duck, duck, (not) goose. Do you see the inward curving outer toes?
Did you see the webbing? Webbing is a useful feature when it preserves, but webbing is inconsistently preserved in bird tracks. If the sediment consistency is just right (firm yet damp, like a firm wet beach sand), webbing may not impress. A more reliable feature is the curvature of the lateral toes: members of the duck group (Anseriformes) with palmate webbing (a completely webbed three-toed foot) have digits II and IV (the outer two toes) that curve towards the middle digit (digit III). Sandpipers with semipalmate webbing (webbing that attaches only partly down the length of the toes) do not have inward curving side toes.

Part of neoichnology is hanging out in an area long enough to see the local wildlife. Ideally, you want to see the animal in question make the footprints. If that isn't an option, you need to know who is frequenting the area. If the tracks you are looking at are fresh, there's a better chance that the trackmakers you see are the owners of those footprints. These tracks were relatively fresh, so I knew that there was a good chance the trackmaker was either nearby or would revisit the site. All we had to do was wait.

While we were waiting, we checked out the track surface for more examples of the same type of footprint preserved in different ways. Here is a great example of how there is not one preservational scenario that will preserve all features all the time.
The webbing on these Canada Goose prints is very poorly preserved, but the hallux (digit I) on the left footprint is gorgeous! Digit I is another one of those birdy features that is inconsistently preserved, yet so many rely on the presence of the hallux impression as THE feature for saying with 100% certainty "Yes! We have a bird print!" I have a paper in press that discusses how the fossil and neoichnology data shows it's rarely that simple. Stay tuned!

We also found great samples of skin impressions for Canada Goose footprints. This print doesn't look like much at first glance - no webbing, no hallux, no "heel" pad (which isn't really a heel, but a fleshy pad where the toes and the end of the metatarsals connect)...
...but on closer inspection, it has great skin impressions!
A close-up look at the footprint shows that it preserves the creases, ridges, and pebbly texture on the bottom (plantar surface) of this Canada Goose's foot.

We also found evidence of our mammalian friends on the track surface: guess who?
If you guessed wolf, you would be correct!
Grey Wolf trackway overprinting the multiple trackways of Canada Goose. Bonus question: was this wolf walking or moving faster than a walk?
While we waited for the arrival of our small ducks (we could hear some quacking in the distance) we made a few plaster of Paris replicas of the different preservational variations of the Canada Goose and the as-of-yet unidentified small duck tracks.
Small duck trackway being cast.

The track surface with plaster replicas (white patches) drying.
Making replicas of modern tracks is a really simple process, and it's something that anyone of any age can do. We use a fiberglass-reinforced plaster of Paris (Hydrocal FGR-95). I also add additional fiberglass matting to the backs of the replicas, as many of my track casts are long and thin. Field neoichnology casting is a cumbersome process: you have to haul out plaster, mixing containers, fiberglass mat (or chop, but that's a pain in the butt to work with) and garbage bags. You also have to haul the awkwardly-shaped plaster casts out of the field. However, I think it's worth it for bird tracks. We're getting mixed results with digital photogrammetry on small bird footprints, and one of the reasons is that they are often wet, shiny, and partially underwater. All of this extra reflection confuses the computer program, which "prefers" even, consistent lighting for all of the images used in making the 3D digital replica. Also, plaster replicas are cheap to make, and I'm an ichnologist on a very strict budget.

This brings me to Important Field Tip #4: Pack it in, pack it out. We mix all of the plaster in a container placed inside a garbage bag, and any plaster drips and slops are collected after they harden. We don't want to leave a trace while we collect traces.

While we were waiting for the replicas to dry, we saw that our small ducks had arrived!
This is a horrid picture, but viewing these ducks through my binoculars let me know that they are Green-winged Teals in their non-breeding plumage. They are a small brown dappled duck, but one was kind enough to rearrange its wing feathers long enough to show me the green patch.

This was a good day for ducks, but where were my shorebirds? We scanned every centimeter of this shoreline, crossed over this waste-deep body of water to a second projection of land and scoured that for shorebird prints, and came up with almost nothing. We saw really faint impressions of Spotted Sandpiper footprints, but they were made in such wet mud that they had all but collapsed in on themselves, leaving nothing but faint lines where the toes impressions should be. We were about to call ourselves skunked in the shorebird category when we came across this:
It turns out there were a pair of Spotted Sandpipers at this locality, but they were being extremely sneaky with us. We turned every corner just to see them flying away: none were comfortable with us in their territory, and they were more or less avoiding walking in areas that would keep an impression of a footprint for more than a few minutes. This was a huge change from last year, when two Spotted Sandpipers took a short nap while I was taking photos of them. On our way back to the field truck at the end of the day, we found out the little buggers had doubled back on us and were foraging in the areas we had already prospected. This brings me to my final Important Field Tip: you can't control your wild study taxa. Some days they cooperate, while on other days they flip you the feathery Bird.

This was a typical field excursion, full of wins (great duck and goose tracks) and fails (the Thrashing of the Tire and my new gravel piercings). Regardless of the frustrating parts, it was great to be back in the field!

Until next time,

P.S. - My thumb turned out not to be broken (yay!) but it was swollen and sore for a few days. Here is a picture the day after I landed on it. Luckily the blisters were just impact blisters - there were no embedded gravel chunks to remove.

Thursday, September 3, 2015

The Past Was Horrifying - Sounds of the Mesozoic

Okay, welcome to my part 2 of X on how the past was likely horrifying if we had lived through it. Today is going to be about what the Mesozoic Era might have sounded like. Apologies ahead of time but this will be a video-heavy post.

When we picture (or rather hear) what dinosaurs (and other prehistoric reptiles) may have sounded like most people will think back to dinosaur movies where the beasts are rampaging. Roaring, snorting, growling, and hissing creatures fill the screen with angry sounds. After the release of Jurassic Park, many of the sounds created by Universal's sound studio have been remixed and reused by other films both on large and small screens. Let's quickly review some of the iconic sounds that these creatures made back in the early 1990s.

Tyrannosaurus breaks out of its pen. Prepare to get T. rekt. Copyright Universal Studios.

My close friend (unfairly portrayed here) Dilophosaurus. Copyright Universal Studios.

The famous scene with Velociraptors in the kitchen. Copyright Universal Studios.

This gives us a great variety of sounds. From the deep bass rumbling roar of the Tyrannosaurus to the chirps of the Dilophosaurus, and the high-pitched screech of the Velociraptor we have great mood-appropriate sounds from our animal villains and protagonists. I especially love the sounds that the Tyrannosaurus in Jurassic Park makes. It gave me chills in the theater all those years ago and it still is exciting to me. But it also makes me question whether an actual Tyrannosaurus sounded like its cinematic depiction.

Since Tyrannosaurus and the other dinosaurs depicted in Jurassic Park are archosaurs, I figured it would be a reasonable place to start looking at the sounds our extinct friends might have made. If we can use extant phylogenetic bracketing for integument and parental care (among other things), why not the possible vocal capabilities? I decided to look at crocodiles and ratites + hoatzin, as my EPB.

What I found was frightening. The first thing I learned is that ratite sounds are not cute.

A modern Rhea, doing Rhea things.

Ostriches with their absurdly low booming sounds.

The frighteningly unexpected growls of the modern Cassowary.

The Hoatzin. Long video, but you can hear the sharp, chuffing near the start between parrot calls.

Being the glutton for punishment that I am, I decided to make myself listen to crocodilian sounds. Not only are they equally terrifying, but they also share some similarities to some of the ratite sounds.
Crocodilians have primeval sounding roars and the occasional hiss.

What is the takeaway from this investigation? For me, it is the idea that screeching, chirping, and otherwise boisterous dinosaurs may not be as plausible as Hollywood would like us to believe. Both croc and modern less-derived birds generally do not make "songs" or "calls" but rather deep rumbles/roars and occasional hisses/clicks. The shriek of the Jurassic Park Velociraptor, spliced together with dolphin and monkey sounds doesn't seem so plausible to me. Nor does the pretty sounding cry of our oddly-hopping Dilophosaurus (or it's rattlesnake-mincing attack cry) make much sense if the similarities between our EPB creatures represent a real signal. But what of our beloved Tyrannosaurus call?

A collection of all the Tyrannosaurus rex sounds from Jurassic Park

To me, this is the most convincing of all the theropod sounds produced for cinema. It sounds the most like the creatures I sampled for my EPB. But there is also another potential problem: size. Just as a tuba sounds deeper than a flute, the size of an animal's resonating chamber (larynx/sirynx) affects the deepness of the sounds it produces. Our largest terrestrial animal today, the African Elephant, is able to produce infrasound (sound too low to hear). The idea of large theropods or sauropods being able to produce infrasound is not itself unreasonable. The large birds and crocs I listened are already producing super-low frequency sounds and crocs are known to produce infrasound during mating season. The Mesozoic world may have been punctuated by low frequency roars and rumbles and silent periods interrupted by a strange feeling in your bones as a large sauropod or theropod let out a noise too low for our ears to hear.

"But wait," my ornithischian fans cry out (Pete, I'm looking at you...)! "What is this saurischian bias?" Well one reason for my saurischian bias is that most (but not all!) movie dinosaurs that make sounds are saurischians. Another is that we have to do a bit less speculation on the possible sounds some ornithischians would have made thanks to Sandia Labs and their 3D reproduction of a Paraaurolophus crest. While not perfect, it gives us an idea of what type of sounds large hadrosaurs may have been able to produce. It is worth noting that this reconstructed vocalization is a low sound, similar to what I've been suggesting for saurischians.

Ignore the metallic overtones...

Compared to the Jurassic Park Parasaurolophus cry...

Moral of the story: the Mesozoic would sound very little like what we imagine it to, based on depictions in cinema and television. Dinosaurs at least would have been making sounds more like their modern relatives than the mixed-up mammal sounds studios are fond of using. This would create an audio landscape deeply unfamiliar to our modern ears.

I'll leave you with one more clip: perhaps the most accurate dinosaur sounds in all of cinema history. Next time from me: discussion of a new tooth paper out in the Journal of Vertebrate Paleontology standardizing theropod tooth nomenclature, an issue near and dear to me at the moment!

1969's Valley of Gwangi, featuring an Allosaurus and a Styracosaurus