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

Brink et al. 2015 - What does it tell us about phytosaurs?

So new tooth news seems to be coming at a rapid pace this year! Several tooth-related papers have come out already and we're barely past the halfway mark. Most recently we have Brink et al. (2015) discussing funky features in meat-eating dinosaurs and, tangentially, other archosaurs. While I obviously love theropods and dinosaurs in general my interest at the moment is with non-dinosaurian archosaurs like our strange Chinle friends from Comb Ridge.

Duane Nash already did a good breakdown of what the article means in terms of theropod dinosaurs and how to relate the findings of Brink et al. to modern correlates as well as exploring what they could mean in terms of feeding and prey capture methods in various dinosaurs. If you haven't read his blog I'll wait.

Okay. Back? Good. As you can tell from both the article and the blog Brink et al. reject the stress-induced formation hypothesis for these interdental folds, as has been suggested previously. Instead they find that these structures are present even before stresses are placed on the teeth - while the unerupted teeth are still in the alveoli. So what does that have to do with Triassic teeth?

If you read the article you will see they sampled a few non-dinosaurian taxa (a phytosaur and an indeterminate Cretaceous croc) as well as the Triassic theropod Coelophysis. We have an abundance of phytosaur teeth at Comb Ridge and have picked up a few teeth we have tentatively IDed as theropod. So not only is Brink et al. a cool paper, it deals with some of our Triassic friends too!

Two views of phytosaur teeth in SEM and thin section, both from Brink et al. (2015), CC-BY
Image C shows mesial denticles under SEM and thin section. D shows a thin section with enamel, globular dentine, and primary dentine.

Brink et al. are looking mainly at the evolution and development of the structures with limited discussion on how the structures would have directly influenced prey capture and processing (though Nash, linked above, goes into that more). One of the more interesting things to me to come out of this is that phytosaurs have interdental fold structures like theropods and unlike crocs, Spinosaurus, ominivorous animals like Troodon and pure herbivores like ornithischian dinosaurs. Brink et al. further state that these adaptations are best interpreted as ways to capture large prey and crush bone. When we talk about phytosaurs, though, most people tend to interpret them as crocodile analogs. Sometimes this means perhaps ambushing large prey, other times preying on fish. This second option has been especially favored for the narrow-snouted forms, viewed by some as not robust enough to deal with large struggling prey.

A Redondasaurus attacks a decent sized prey item - a silesaurid. From Edyta Felcyn: go support her art!

There is some other evidence to suggest that phytosaurs were not just meekly eating fish and moderate-sized animals like dinosauromorphs (see image above). Coupled with their teeth that were perfectly adapted to ripping up large struggling prey items and mashing their bones, we have trace behavioral evidence to indicate this is exactly what happened. Last year Drumheller et al. documented a phytosaur attack on a living rauisuchian. You can read PastTime Podcast's take on the paper if you don't want to read through the paper itself. In short, though, they find evidence that a phytosaur tried to wreck shop on a rauisuchian, an animal that was basically a cross between a tyrannosaur and a crocodile. Wreck so much shop, in fact, that the phytosaur tooth went almost completely through the femur of the rauisuchian. This unfortunate fellow was then attacked by another rauisuchian and finally scavenged by a smaller phytosaur. Times were rough in the Triassic, even if you were the biggest, baddest fellow on the land.

Damaged psuedosuchian femur. The phytosaur attack is represented by the embedded tooth in Box A. Image from Drumheller et al. (2014).

If encounters like this were rare and the exception to the normal behavior of phytosaurs then the fossils described by Drumheller et al. are truly remarkable. Between the marked heterodonty found in adult phytosaurs described by Hungerbühler (2000) and the new evidence that they possessed dental adaptations that enabled them to capture, kill, and process prey larger than them it seems unlikely that this was a one-off chance encounter.

Ventral view of phytosaur snouts from Hungerbühler (2000). Note the different size and shapes of the teeth in this view.

 Instead our view of phytosaurs as fish-eaters occasionally attacking small-to-medium-sized land prey needs to be challenged. Phytosaurs were equipped with a dental battery that enabled them to routinely tackle large, dangerous, struggling prey as adults. This would include animals that were significantly larger than them. While juvenile phytosaurs seem to lack these dental adaptations (see, for example, my earlier post on this topic) and likely pursued prey smaller than themselves, adults would have been terrifying creatures to behold.

An interesting point to consider too: if phytosaurs were more like Nile Crocodiles than gharials, why don't we see ziphodont dentition in crocs? Certainly wildebeast and zebra don't give up after a fight. Brink et al. note that their Cretaceous croc also lacks ziphodont dentition, suggesting the behavior of crocs and their prey haven't changed much. Modern crocs are obviously capable of tackling large prey (though usually not larger than their own body). If they have gone hundreds of millions of years without the interdental folds and can eat large land prey, what were phytosaurs doing different?

Crocodiles and their prey in Africa - 2:57 from National Geographic

We don't have the fossils to answer that definitively but it would appear that modern crocodiles are not as good of an analogy for phytosaurs as has long been supposed. Hopefully future work at Comb Ridge and across Triassic collections will lead to new insights, clarifying what this unique clade was doing.

As an end note, Brink et al. suggest that ziphodont dentition with interdental folds is basal to all theropods, even thought phytosaurs possess the same tooth structure. It would have been nice to look at things like pseudosuchians from the Triassic to see if similar dental structure existed. If so, perhaps this sort of adaptation dates back to the rise of archosaurs in general. I guess that's another paper for another time.

Next up from me: a return to the lighter side. I'm going to be reviewing Richard Delgado's new Age of Reptiles comic series, Ancient Egyptians!

References:

Brink, K. S., Reisz, R. R., LeBlanc, A. R. H., Chang, R. S., Lee, Y. C., Chiang, C. C., ... & Evans, D. C. (2015). Developmental and evolutionary novelty in the serrated teeth of theropod dinosaurs. Scientific reports, 5.

Drumheller, S. K., Stocker, M. R., & Nesbitt, S. J. (2014). Direct evidence of trophic interactions among apex predators in the Late Triassic of western North America. Naturwissenschaften, 101(11), 975-987.

Hungerbühler, A. (2000). Heterodonty in the European phytosaur Nicrosaurus kapffi and its implications for the taxonomic utility and functional morphology of phytosaur dentitions. Journal of Vertebrate Paleontology, 20(1), 31-48.

'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.

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!