Questions: BBC’s Prehistoric Planet, Episode 2

[Sightreader]

Hello everyone!  I’m relatively new to the world of dinosaurs and was watching BBC’s “Prehistoric Planet”.

 

As David Attenborough states before every episode, “we now know SO MUCH about the world of dinosaurs… this is their story”. The confidence of that statement - combined with Attenborough’s formidable reputation amongst laymen - makes me hopeful that the show doesn’t contain complete speculation without disclaimers. However, they show a lot of stuff that I’ve never seen in my limited reading.  Does anyone know what sorts of evidence might they have for this these behaviors?

Episode 2 - “Deserts” - begins with a massive group of male Dreadnoughtus - portrayed walking with necks relatively erect, like brachiosaurs - wandering far from their forests, plodding through the desolate South American desert to where a large group of females awaits them - in the middle of nowhere - to breed. Rows of what the show itself acknowledges to be “bizarre” balloon-like “gular air sacs” inflate up and down along the length of those immense necks, each allegedly connected to a series of “bellows” inside their neck bones. Battles for mating competition amongst males seems to be based on (what looks to me) like walrus behavior, with the massive creatures rearing up on their hind legs, falling forward until they slam into each other, followed by their relatively vertical necks slapping into each other as heads bite at each other’s necks. In the meantime, grappling forelimb spikes stab at each other’s torsos. 

What sort of evidence would be required to ascertain such behavior? Are there fossil finds of mass mating gatherings of Dreadnoughtus in South American deserts? I know that titanosaur vertebrae were extensively pneumaticized, but what’s the evidence that it was as a “bellows” system for inflating gular air sacs along the neck? If these sacs are self-described as “bizarre”, then wouldn’t the “extraordinary claims, extraordinary evidence” standard have to be applied in regards to their portrayal? As for the body-slamming, is there osteological evidence of inter-species impacts and injuries of the sort portrayed here? 

In the next segment, what looks to me to be a spectacularly GORGEOUS rendering of a Mononykus darts about through the desert to come to dead branch where it uses its specialized hearing adaptations to detect the sound of termites within. Specialized claws punch through the dead wood and a tongue - “twice the length of its head” - darts into the branch’s interior to grab up termites. Can we identify the length of tongues from the structure of the skull and neck? Anyway, the fidgety little creature absolutely suspends all disbelief in its rendering - especially when its feathers get soaked in a rare desert downpour - until it zips around a corner without banking at all. Not as severe as the sharp turns seen by the “compys” of Jurassic Park II, nevertheless, I find myself wondering whether such a small, agile theropod might have to LEAN INTO their turns as opposed to taking them utterly upright? A tantalizing glimpse of a flock enantiornithines appears in the foreground, completely blurred in front of our Mononykus stalking from the background. Our hero’s attempt to catch one completely fails - along with any hope of a closer look at a rendering of an “anti-bird”. What, specifically, was backwards about these birds? I never fully figured that out.  

There’s a brief segment of a desert watering hole in which an enormous variety of dinosaurs are gathered shoulder-to-shoulder, reaching over and under each other to take a sip. Even the arrival of a Tarbosaurus doesn’t break up the gathering; the Tarbosaurus is shown having to scoop water into its lower jaw to drink. Is there evidence of such mass gatherings of all sorts of species in the same watering hole? There must, I assume, be evidence that Tarbosaurs didn’t have a tongue or any other alternate, more efficient means of drinking. 

Barbaridactylus are shown congregating in isolated desert cliff plateaus, landing on their hind legs and competing for females. Have massive congregations of these creatures on desert plateaus been found? One male is shown chasing a competing male and “shooting it down” by nipping and tearing at its legs and wings until it falls from the sky and crashes in a heap. Have such injuries been established? They also make the assertion that females seek the maximum number of sexual partners in order to breed the fittest young. Are there statistics of this sort to back this up? Wouldn’t such a lack of selectivity would be a disadvantage? 

The final segment takes place in the gypsum dunes of South America. The hadrosaur Secernosaurus is shown with round pupils. I found this curious; I would assume these dinosaurs would have open range, herbivore lifestyle that would lead to the sort of horizontal pupils you see in cows, horses and lambs. I suppose this could be tested: these sorts of eyes require muscles that allow the eyes to rotate so when the animal tilts its head for feeding, it can keep the horizontal slits aligned with the horizon. Perhaps such muscles would result in attachment sites on skulls? Anyway, the Secernosaurs, like most of the dinosaurs in the series, have inner eyelids that blink at right angles to their outer eyelids. Wikipedia says it appears to be likely - but not yet a sure thing - that Secernosaurus lived in these vicious deserts, and along with that the show asserts their ability to migrate using stars for navigation. They also talk about their ability to hear ultra-low frequency sounds: clearly the skulls of hadrosaurs display all sorts of mysterious adaptations; would such hearing manifest itself osteologically? Finally, they show Secernosaurus licking their own skin for evaporated moisture as they move from arid air to the moister air of the coast. 

Thanks for any feedback you have on the questions I’ve posed here! Clearly I have a lot to learn… 

[GreatHoatzin]

You seem to have a pretty good grasp of things already!

I’d say a lot of these behaviours and anatomical obscurities are speculation. We have to remember that these are behaviours that occur when the animal is still alive, while fossils give us an image of after it died. (That’s why we can’t know if there were gatherings of species at water holes except from trace fossils, which are rare). There may be some injuries or marks in bones that help us deduce what may have happened in a lifetime, but it isn’t always certain.

As you said about the air sacs, I do not believe there is any evidence for it. They’re taking inspiration from modern day dinosaurs, birds such as the male frigate bird. It is quite likely that in the hundreds of millions of years dinosaurs were around that some might have evolved a feature such as this. 

The Mononykus’ quick turns might have just been an animation oversight, you can’t get everything right.

with the Barbaridactylus, again, they’re taking inspiration from modern birds. I imagined ravens, who nip and bite at eagles to rob them of their food. The mating is just speculation as well, though this behaviour is seen with a few animals today.

It’s the same story with Secernosaurus, although many believe they had quite complex hearing, with the evidence of their complex nasal passages, which we think could create a variety of sounds and pitches. Interesting thought on examining the skulls for muscle attachments. I believe it would be pretty difficult to determine where eye muscles attached, as they aren’t the same as simpler, larger muscles.

I hope I covered most of your questions. I think the main goal of Prehistoric Planet was to show dinosaurs like any other animal. In all the old shows and movies it was lots of hunting, and battling, and that’s what many people imagine dinosaurs as: vicious brutes we do nothing but attack each other. The documentary presents them as any animal you would on a modern-day nature documentary.

 

 

[Sightreader]

Yay!  Thanks so much for the great feedback; that’s SO informative!  I didn’t realize anyone replied to this… I would have thought it would have emailed me if someone replied, so I must not have the settings right. 

 

I ask because everything I know about dinosaurs doesn’t go much beyond a glorified book report.  All I can do when watching a show like this is simply pile speculation upon speculation!

[Lone Hunter]

I think you only get an email if you get a personal message from someone.  Ironic I just got through watching La Brea which I'm hooked on, it's refreshingly different and making me wish I could make friends with a baby wooly rhino  Wondering how accurate this show is, I didn't realize the rhinos were the size of a bus.

[Fossildude19]

22 minutes ago, Lone Hunter said:

I think you only get an email if you get a personal message from someone.  Ironic I just got through watching La Brea which I'm hooked on, it's refreshingly different and making me wish I could make friends with a baby wooly rhino  Wondering how accurate this show is, I didn't realize the rhinos were the size of a bus.

 

 

You can follow a topic, and get notifications by email or pop up on the website if your settings are set correctly. 

[Sightreader]

Interesting… I got notifications for these last two! From looking at the date of the reply, it would appear that arrived at the worst possible time for me: a teacher trying to cover extra classes (indefinitely) for a new hire who bailed on us just before school started. I strongly suspect it’s MY fault, not the forum’s, as all sorts of organizational breakdowns were destroying me at the time.

 

I saw some of La Brea - maybe a couple of episodes or so, just enough to know that it was some sort of time thing that got us back to prehistoric mammals, something that is almost never given attention in pop culture. As basic as my knowledge about dinosaurs is, though, my knowledge about extinct mammals is just about non-existent! 
 

In the meantime, I’m desperately trying to cover up all the primordial sinkholes ventilating my lesson plans for school…

Edited September 28, 2022 by Sightreader
Inept grammar.

[GreatHoatzin]

11 hours ago, Sightreader said:

Yay!  Thanks so much for the great feedback; that’s SO informative!

I’m glad you liked it! I had a lot of fun writing it

[Sjfriend]

The one thing that always taints my watching/ reading paleontological things is even with having living animals to watch there is still a fair bit of speculation about many of those still living. So, you can only imagine how that works out for long dead ones  I know they try to "educated guess" as much as they can from comparing living to fossil life but we have to know that. Unfortunately they don't always do a good job of pointing that out in programs. 

[Sightreader]

12 hours ago, Sjfriend said:

I know they try to "educated guess" as much as they can from comparing living to fossil life but we have to know that. Unfortunately they don't always do a good job of pointing that out in programs. 

Yes, you’ve hit the nail on the head: their failure to warn us of their educated guesses, more than anything else, is what really bothers me about this show. Yes, I am absolutely in love with their portrayal of dinosaurs as everyday animals just trying to scratch out a living like the rest of us and I support that goal even if it requires vast amounts of speculation (unlike Jurassic Park Dominion, which seems to have totally abandoned the idea that these might actually be animals).  I simply can’t sing enough praises for the beauty and quality of Prehistoric Planet’s reconstructions and their discipline in moderating the behavior they portray.

 

On the other hand, rather than exciting our imaginations by encouraging us to wonder what might or might not be and join in on the speculation, they instead seem to go out of their way to prevent us from questioning what’s shown. Not only does Attenborough say, “we now know so much about the world of dinosaurs… this is their story” - a formidable assertion suggesting some vast new trove of evidence that scientists simply can’t wait to put on screen - but it also suggests that all the research for their speculation has already been done for you by saying, “go to our website to see the science behind the episode” - as if every little detail portrayed has a blurb already documented in their vast website library. In actuality, the website only contains a single featurette for each show with evidence for the absolute least controversial thing they portray - “Gee, footprints show theropods swam” - while completely omitting evidence for the other 58-some minutes.

Edited October 1, 2022 by Sightreader
Grammar and clarity cleanup