Saturday, October 24, 2015

A Paleonerd's Analysis - BBC's Walking With Dinosaurs Part 1

Not to be confused with the telepathic Pachyrhinosaurus of a certain 2013 movie.
Walking with Dinosaurs was a landmark documentary series which first aired in the Spring of 1999 and remains to be relatively popular today. The series took a novel approach to educating people about dinosaurs by using actual wilderness and backdrops of nature alongside CGI and mechanical puppets of extinct animals in an effort to simulate a Planet Earth or Life-style nature documentary. And it worked too, as the Walking with... series has come to span a large range of media, including two sequel series, a prequel miniseries, three spin-off specials featuring Nigel Marvin, a spin-off that Nigel himself started which was based off the spin offs he was featured in, a computer game, an arena spectacular show, a movie featuring telepathic Pachyrhinosaurus, a better version of said movie without telepathic dinosaurs, a spiritual successor, and endless merchandise that's too vast for me to list off.

However, one thing many people forget about this series is just how controversial it was when it first came out, especially among paleontologists. Even today minds are split on how much the show put a big emphasis on speculation and sensationalism rather than using a much more factual approach. The creators of the original series have said that their goal was to entertain, and that since theories about prehistoric animals are always changing, they couldn't possibly keep up with informational input. Even at the time the series came out, there was a number of "facts" presented which were wrong, and many more ideas which were correct at the time have since become dated.

This all made me curious just how much the show has aged with time, as well as how our view of these animals has changed too. So, after something like seven years, I sat down and decided to watch the series again. I'm still looking through the other episodes again and jotting down notes, but as soon as the next batch has been viewed I will be sure to post my observations here.

Here's some notes of things I noticed while watching the first two episodes of the series: First Blood and Time of Titans. Keep in mind that these notes are not just limited to facts presented, but also just observations I experienced about the show as a whole. I'll also try to note if the fact presented was true at the time or not, but just assume when reading through that the info was unknown at the time. Note also that I'm not going to go into too much detail about all the animal models, as I would take WAY too much time on the theropods alone. (i.e. broken wrists, shrink wrapped, tail too skinny, feather this, feather that, etc.)
-New Blood-
  • The program claims to take place in the Chinle Formation 220 mya, which would correlate roughly to the Blue Mesa and Sonsela Members of the formation. If that's the case, the environment is all wrong. Much of the Chinle 220 mya was a huge, dense swamp with a number of meandering rivers, and fossil preservation shows dense vegetation, large fish, massive metoposaurs, and phytosaurs making up a big portion of the fauna. It was only during the younger Owl Rock Member (~207 mya) that the environment started to become much more arid and desert-like.
  • Tying into the above, Coelophysis remains are supposedly from the Petrified Forest Member of the Chinle (~211 mya), which puts the star of this episode ~10 million years later in time than presented in the documentary. This can also be said for a number of other animals in the series as a whole, but I'll get to them when they come.
  • Kenneth Branagh (the narrator) is treating dinosaurs like they're some ultimate animals which are better than everything else in every single way. This reflects a lot of thinking in the late 1990s that dinosaurs were somehow superior to all other Triassic reptiles, but in fact, most recent research shows that they were not very unique in regards to anatomy, and in fact there were many other archosaurs (particularly things like Postosuchus and Effigia) which had almost all the same abilities dinosaurs had. Current consensus is that, as is the case with many evolution and extinction scenarios, dinosaurs just happened to get lucky and survived the Triassic-Jurassic Extinction event, allowing for their diversification.
  • I know at the time nobody really cared and that some people still don't, but can we please stop referring to synapsids as "reptiles?" They're not "reptiles", nor are they "mammal-like reptiles". Proper terminology would be stem-mammals, proto-mammals, or, ya know, just "synapsids".
  • The whole comment by Branagh on how the Placerias are the last of their kind and an "endangered species" might sound overly poetic, but in fact Placerias are only known from the very lowest parts of the Chinle, suggesting they disappeared rather early in the formation's history. Still, an “endangered species” title is rather bizarre choice of words.
  • The Placerias are so slow. Seriously, why? I understand they're big herbivores with semi-sprawling feet, but Hippos are pretty fast runners, and crocodilians can gallop, so why? I know tortoises who can outrun these things.
  • The "cynodonts" in the show are probably based off Kraterokheirodon colberti teeth in the Chinle. Although initially assigned to cynodonts, a 2005 study found them to be very distinctive to the point that they can't be confidently assigned to any known amniote group, leaving no evidence of cynodonts in the formation.
  • WWD had hairy, milk-producing proto-mammals before it was cool. Although, they do seem strangely a bit too carnivoran-like in behavior. Not that that's a bad thing.
  • "Postosuchus, a merciless ambush predator. The largest carnivore on Earth." Any number of the 6+ meter phytosaurs from the same formation would like to object to that. Also, Poposaurus got nearly as big as Postosuchus, and there were even bigger rauisuchids from elsewhere in the world at the same time. Postosuchus is far from the largest.
  • Postosuchus has upright limbs, long hind legs, and was recently shown to be capable of bipedal movement. So why the heck is it so slow? Seriously, all the animals outside of Coelophysis are moving at a snail's pace. I feel this is all a plot just to make the dinosaurs seem more interesting.
  • Peteinosaurus is from northern Italy, not the Chinle formation. Given, there are small isolated pterosaur bones from Chinle, but they seem to come from a very different type of animal than Peteinosaurus. (The Chinle specimen/s seem to be more similar to Eudimorphodon.)
  • Everyone always says in these documentaries that pterosaur wing membranes were delicate. Never mind most of the work that's come out (especially in recent years) talking about the layers upon layers of tissue reinforcements that's been found in their wings.
  • Peteinosaurus hunting dragonflies. I'll let Darren explain why this is unlikely.
    "Sorry, I still think it's dumb when artists show prehistoric animals chasing dragonflies. Have you ever tried to chase a dragonfly?" - Darren Naish
  • Seriously though, early pterosaurs including Peteinosaurus don't show the best flight capabilities, and much of their anatomy suggests they hunted prey (like lizards, small mammal-y things, and decent-sized insects) on the ground rather than in the air. It was only more specialized pterosaurs like anurognathids which developed the wings and bodies to catch flying insects, and even these animals likely lacked the speed required to catch high-speed insects like dragonflies regularly.
  • The wound on the Postosuchus' thigh really doesn't look that bad considering the injuries most Mesozoic archosaurs have been shown to live through, and she doesn't even really limp. I guess Postosuchus are just really wimpy. (Pro-dinosaur propaganda, say!)
  • With their dinosaur-chasing abilities and constant snarling, I'm wondering if cynodonts were the honey badgers of the Triassic. Was that the actual inspiration for their behaviors in the show? Heck if I know.
  • I might be wrong, but the male Postosuchus marks his territory with urine, which is pretty mammal-like and not what I think is typical of most reptiles. Most reptiles use visual signals to assert dominance, and when marking with scent they tend to use pheromones or "musk" rather than urine. If anyone knows otherwise, please tell me.
  • "...the dinosaur’s unique serrated teeth..." Uh, serrated teeth is a pretty common trait among reptiles, and animals in general. It sounds like they're trying to make dinosaurs look ultra-superior or something, but it just comes off as goofy.
  • Something for future dinosaur documentary makers to keep note: DON'T make your animals scream, squeal, roar, screech, hiss, and call ENDLESSLY when they're just wandering around foraging. During confrontations, communication, and courtship behavior its fine, but these Coelophysis are screeching every second for no good reason. And yes, it's really annoying.
  • How does a tiny wound on a single leg lead to full hindleg paralysis? They don't mention infection or anything, and the wound doesn't look like it's gotten any worse at all.
  • The music is telling me I should feel bad for the Postosuchus, but what exactly did she do this whole time? Eat a Placerias, roar a few times, and walk around a lot. I don't feel this is sad music worthy material.
  • Kenneth Branagh goes into gory detail about how the Coelophysis "use their jaws and front teeth to reach under the Postosuchus's scales and eat her from the inside out", but isn't this just how all predators eat? Open up the abdomen and dig in from the inside?
  • A key point argued for why dinosaurs took over the Earth and left other reptiles in the dust after the Triassic is they were better-adapted to drought because they excrete very little water. There is a theory proposed that archosaurs were better adapted to the dry Pangean climate after the Permian-Triassic extinction event because they didn't loose very much water when they excreted, but here they're arguing that dinosaurs were somehow better at conserving water than every other reptile group. Someone care to explain how dinosaur poop is any different from other archosaur poop? I highly doubt this is true.
  •  Coelophysis cannibalism reference. Coelophysis was long thought to have been a cannibal due to the discovery of juvenile Coelophysis bones in the gut regions of a few adults. However, many of these were eventually shown to be from the sphenosuchian crocodylomorph Hesperosuchus instead, leaving the evidence for that idea invalid. Even so, given that cannibalism is a common behavior in living organisms, and it's now known in later theropods, I don't doubt that Coelophysis was any different. Still, the fact that this trait is so commonly tied to the animal gets annoying.
  • Plateosaurus is from Europe, not the Chinle. Yes there are basal sauropodomorph footprints known from older layers of the Chinle, but then why even call them Plateosaurus? Why not just call them "prosauropods" like how the narrator was ambiguous with naming the cynodonts?
  • Plateosaurus could not walk on all four limbs like shown, as the hand was unable to pronate in such a way to allow quadrupedal movement. There are other "prosauropods" which could walk with a quadrupedal gait, but Plateosaurus was not one of them. (More reason to just call them "prosauropods".)

-Time of Titans-

  • This episode starts off with a female Diplodocus laying her eggs via an egg elevator. At the time scientists postulated as to whether or not sauropods utilized an egg elevator, or simply squatted. I’m pretty sure that the idea they simply squatted has won out these days, but this was mostly just speculation on the documentary’s part.
  • Mention that Diplodocus was the largest Jurassic dinosaur. Err, it’s really complicated as to which sauropod was likely the “biggest”, but Diplodocus definitely wasn’t one of them. Heck, I don’t even think it’s in the top twenty anymore. Average size is supposedly around 12 tonnes.
  • The Diplodocus hold their necks vertically out in-front of them and parallel to the ground. WWD was made during a time when many people were arguing over the position of sauropod necks, with a certain group arguing that they held them out parallel. More recent research has shown that this is most certainly not correct, and that sauropods probably held their necks in an S-shaped fashion like all other known land tetrapods.
  • All the sauropods also have nostrils on the tops of their heads. This was thought for the longest time since most saurpods have the nasal skull openings above the eyes, but it was more recently found that sauropods had fleshy nostrils which extended down past the bony openings to the end of the skull. No idea why they had this weird feature, but it might have had to do with a resonating system or for cooling the brain. They definitely didn't have noses on top of their heads though.
  • We get a time frame of ~152 mya, which would place this episode smack-dab in the middle of the Morrison's depositional history. This suggests that the Diplodocus presented are D. carnegii, but the setting is Colorado, while D. carnegii was best known from Wyoming at the time the series was made. However, D. longus, which is known from Colorado, was recently  found to be a nomen dubium in the big Brontosaurus paper, and is now lumped into D. carnegii, so I guess it works out now. *EDIT: see bottom.
  • Ornitholestes with a horn. This interpretation was suggested by Paul in his ever-famous book Predatory Dinosaurs of the World, in which the nasal bones were broken and made it look like the animal had a nasal horn in life like Ceratosaurus. This was corrected in later studies.
  • Just wanted to point out that Ornitholestes is literally the only non-avian dinosaur in the whole series which has feathers, and even these are hard to interpret as feathers (they're just tiny mobile quills). I should also note that dinosaur feathers had been discovered three years prior to the show's airing, and had been suggested by scientists as early as the 1980s. In other words, the show has no excuses. Even for the time, we knew feathers should've been included in a variety of the dinosaurs.
  • The "sauropodlets" are pretty cute. Not sure if they're spot-on to what we know of hatching sauropods, but they look pretty good to me even by today's standards.
  • Mention that the necks are stiff. Again, I think this was heavily disputed at the time, and I think even today it's still a controversial topic, but from what I've heard most experts now agree sauropod necks were decently flexible and could move in a range of motions. Although, it might differ a bit from species-to-species.
  • Diplodocid tails were rather flexible, but I don't think they were that flexible. They look more like someone tied a ribbon to the tail than an actual functioning tail in some scenes. They also mention that the tails were used in visual communication, but don't mention the idea that it could make a sonicboom like some models suggest. The sonicboom idea was first proposed in 1997 though, and had a fair deal of skepticism at the time, so I guess they just wanted to go the safe route.
  • Everything about the Anurognathus. Seriously, everything. Wrong lifestyle (based on what we know from it's anatomy), wrong appearance (even by late 90s pterosaur standards), and wrong side of the world. Anurognathus is known from the Solnhofen limestone of Germany, not the Morrison rocks of Colorado.
  • Anurognathus hunting damselflies. Look above to the Peteinosaurus comment.
  • There's a short segment of the episode talking about dung beetles and how they had their start feeding on dinosaur dung in the Jurassic. However, this might not be correct. Recent research into the origins of true dung beetles of the subfamily scarabaeinae has shown that while they originated in the Mesozoic, much of their diversification was tied to the Cenozoic mammal radiation, and that they were rare components of Mesozoic ecosystems. Instead, there's now evidence that an extinct group of cockroaches called the blattulidae were the primary consumers of Mesozoic dinosaur dung.
  • The "sauropodlets" form creches with individuals of the same age, which fits well with all the recent research suggesting that non-avian dinosaurs primarily tended to live in age-related groupings.
  • The Stegosaurus individual pumps blood into it's plates in only a few seconds, which is highly unlikely given that stegosaur osteoderms were likely covered in keratin. Keratin, as we all know, is dead tissue which doesn't have active blood vessels in it. Thus, it pumping blood into it's plates at such a rapid rate is extremely unlikely.
  • Branagh talks for a bit about how sauropods probably altered the environment around them during their foraging, which was a rather new idea at the time, but has become an increasingly interesting topic with research on how elephants affect African landscapes, as well as what computer simulations tell us about how the existence of sauropods and other large dinosaurian herbivores literally altered the Mesozoic climate.
  • This might be a nitpick, but Branagh mentions that the Diplodocus use gastroliths to grind up the food they consume. However, Wings and Sander (2006) analyzed this idea in detail and found that it didn't hold up, as sauropods only have a tiny percent of the required gastrolith numbers to preform proper grinding. Instead, they propose that gastroliths were instead swallowed primarily for detangling the mouthfuls of thick vegetation the dinosaurs consumed and preventing it from clogging the digestive system.
  • The juvenile Diplodocus are so slow when running away from the forest fire. Branagh mentions that they're this slow because "they always need three legs on the ground," but elephants have the same issue and they can run pretty fast when they need to.
  • Now Branagh says that Brachiosaurus was the biggest Jurassic sauropod, and while that's probably closer to the truth than Diplodocus, there are a number of bigger sauropod candidates.
  • Adult Diplodocus are said to be "programmed" to respond to juvenile calls. I don't know, sounds a bit too elephant-like in behavior to me, and sauropods don't care for young to begin with. Then again, soft shell turtles were recently shown to do something similar. Guess it's up to interpretation.
  • The next segment is all nothing but speculative courtship behaviors for sauropods, and while it is an interesting interpretation, I wish Branagh wasn't speaking during it, because then it seems like he's presenting all these courtship behaviors as true facts. If they had left it silent and the behaviors were just left to be interpreted, then it would be much more factual.
  • There's mention that female Diplodocus have fused hip vertebrae in order to support the weight of the male. This was actually a postulated idea in the late 90s which had some support behind it, as some sauropod specimens were found to have fused hip vertebrae and some didn't. However, eventually this trait was singled out as more likely representing ontegenetic features rather than male-female differences. I lost track of the paper proposing this though... (Anyone know of a link?)
  • These are some terminator Allosaurus. One of them falls off the back of a sauropod onto it's tail (Ouch!), and the other gets smacked in the side by a massive 100ft individual and shakes it off. I'd expect the latter at least to have an internal skeleton resembling Big Al or the Smithsonian Institution's specimen; completely riddled with injuries.
  • The Postosuchus in the last episode is poked in the leg by a Placerias tusk, creating a tiny wound which leads to agonizing pain and suffering lasting for months and costing her her life. Meanwhile, the Diplodocus has her entire belly torn into by an Allosaurus' massive jaws and forelimb claws, and Branagh is like "Eh, don't worry, she'll recover."
  • Mention that sauropods can live over a hundred years. In fact, the oldest sauropod to which we have directly estimated the lifespan of was roughly 50 years old, and the majority of Diplodocus individuals seem to have been between 12 and 25 years of age, so we lack any evidence of hundred-year lifespans in these animals. However, given that many sauropods did get much larger than the species with lifespans studied, and that most dinosaur specimens are immature, I wouldn't be surprised if larger sauropods had century-spanning lifespans. Just probably not Diplodocus.
  • Branagh goes on to say sauropods were "displaced by later dinosaurian herbivores." This really only seemed to happen in North America during the Late Cretaceous, 95 mya after the Cretaceous Thermal Maximum. North America prior to that time, as well as the rest of the world, was still sauropod-filled right up until the end of the Mesozoic. Not just that, but sauropods did manage to recolonize North America during the Maastrichtian in the form of Alamosaurus, and fossil discoveries from other late Cretaceous bonebeds might suggest they were there even earlier. So yeah, they weren't displaced and were going strong till the end. At the very most, they just had a rough period in just North America.
*EDIT: I was informed after writing this that the Diplodocus longus specimens have be reassigned to D. hallorum, NOT D. carnegii. This would actually make it more likely that  the species featured in the documentary is meant to be D. hallorum, as they are actually found in Colorado and got to much larger sizes than D. carnegii.

And that's about all I can say about the first two episodes. As you can tell by the length of the list, a lot of things have changed since the show has come out, and a lot of the information is definately now dated. Of course, that could just be due to my academic mindset; after all this is supposed to be a series for the public, but even then it's falling a bit short. Oh well, hope the next two episodes are better......

Wait, the next episode has the blue whale-sized Liopleurodon... Crap.

Cheers!

3 comments:

  1. I disagree with you on the Jurassic Pterosaurs being unable to catch dragonflys.

    ReplyDelete
    Replies
    1. Why?

      I mean, "unable" is a strong word, but do you really think they did actually do that so often that it could be shown in such a "documentary"? If so, why?

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    2. What I meant by that statement is that I didn't think that pterosaurs would *routinely* feed on dragonflies. Dragonflies and their relatives are incredibly agile insects that even the most agile birds today have a lot of trouble catching. Anuragnathids are perhaps the fastest and most well-adapted for catching aerial prey among pterosaurs, but even they would likely have great difficulty catching something like a damselfly, and would probably focus instead on slower-flying insects. However, if the damselfy was in a bad spot, injured, or otherwise easily catchable and a pterosaur was nearby, I don't see why the pterosaur wouldn't try to grab it, if at least once.

      Delete