Saturday, September 17, 2011

Planet Dinosaur Review

Since I reviewed Dinosaur Revolution, I might as well tackle the other big dino documentary that came out this month.  As with Dinosaur Revolution, this review only covers the first episode, which in this case was about Cenomanian North Africa.

Planet Dinosaur's special effects range from decent to sad.  While I could go on about the little details like Ouranosaurus chewing like a mammal, having depressions where its laterotemporal fenestrae are, Microraptor lacking primaries attached to its second finger and having wings which are too short, etc., the simple truth is that the dinosaurs are less accurate and less believable as real objects.  The maniraptorans (Troodon, Microraptor, Epidexipteryx) are especially poor.  That's not to say it's all bad.  The Rugops (possibly an Aucasaurus from the Auca Mahuevo episode) and Sarcosuchus look pretty good, the Spinosaurus is decent except for its short tail, and the Ouranosaurus dying had nice motions and rapid breathing.  Seeing this show really made me realize how good the models and animation were in Dinosaur Revolution though.  It's such a shame the talent/money spent on the latter couldn't have been used for a program like Planet Dinosaur.

As far as behavior goes, it was refreshing to see dinosaurs acting like dinosaurs.  There are a few stupid things, like Spinosaurus eating part of a fish, then leaving to catch more ("with prey plentiful, Spinosaurus can afford to be wasteful").  Or Rugops' subsequent portrayal as an obligate scavenger.  Or Spinosaurus slashing the fish with its hands, only to eat tiny bits at a time. But at least nothing they do is human-like.  The behavior is largely defended by reference to actual studies (see below), and the show does a good job of making a story based on these.  The larger narrative of Spinosaurus being the largest and last spinosaurid and dying from climate change was flawed because Late Cretaceous African dinosaurs are poorly known, and Hone et al. (2010) and Candeiro et al. (2004) described Santonian spinosaurids.  But Candeiro et al.'s conclusion was doubted in their 2006 paper and Hone et al.'s study is quite new.  Bearing in mind I don't know how accurate the paleoclimatology was, the larger story felt more plausible than Dinosaur Revolution's apparently tacked-on story of how dinosaur parenting helped their success.

My favorite part of Planet Dinosaur is that it manages to explicitly incorporate numerous journal articles.  These are shown in informational panels with the year of publication, age, country, and figures from the original articles or photos of specimens referenced by them.  They even managed to rotate one of Stromer's Spinosaurus vertebra drawings in 3D, haha.  We have Stromer (1915), Dal Sasso et al. (2005), Amiot et al. (2010), Dal Sasso et al. (2009), Sereno et al. (1996), Tanke and Currie (2000), Sereno et al. (2008), Kellner (2004), Charig and Milner (1986), and a biomechanical strength analysis of Carcharodontosaurus' jaws.  I don't know how much I agree with some of the conclusions (like amphibious spinosaurids), but at least they're actually from the scientific literature and not just random made-up possibilities. 
There are ocassional errors, like overlaying a tyrannosaurid dentary on Sinraptor's skull, or using Stromer's reconstruction as the basis of the Spinosaurus skeletal, resulting in one of the worst reconstructions I've seen.  It's good they knew to tilt it horizontal and give it the right skull, but the anatomy!  Sacral neural spines lateral to the ilium, the femur articulating with the postacetabular process, two sets of pubes... I could insult it all day. 

Please put this travesty out of its misery
And yet other details of their informational panels are accurate, such as Irritator and Siamosaurus being inconspicuously listed as additional spinosaurids on the map.  Overall, it's quite good.  I actually learned what Onchopristis was, and that there's a partial Spinosaurus maxilla with an Onchopristis tooth embedded in it (not just MSNM V4047 with its embedded vertebra).  There's also apparently a Spinosaurus neural spine found in 2008 in Morocco that had been broken in life, which I had never heard of.  Any time a dinosaur show manages to teach ME something, I'm impressed. 

So I quite liked Planet Dinosaur.  It's almost the exact opposite of Dinosaur Revolution- generally inaccurate restorations behaving fairly realistically, packed full of references to specific discoveries in the literature, telling us what we know and why.  I'll be watching the following episodes, and contra my earlier statement I'll probably tune in to the other Dinosaur Revolutions too.  I'll just have to treat the latter like the Transformers 2 of dinosaur programs- pretty to watch, but turn off your brain.  On the other hand, I'll be interested to see if Planet Dinosaur presents any more discoveries I hadn't heard of. 

Tuesday, September 13, 2011

Dinosaur Revolution review

Well, that was painful.  I decided to join the trend and review the show that's been so hyped- Dinosaur Revolution.  Little did I know my yearly allowance of eyerolls would be used up.  I only watched the frirst episode "Evolution's Winners" and frankly have no desire to sample more.

First the good.  The models were usually excellent, with non-pronated hands and all that good stuff.  I especially enjoyed the dilophosaurian snouts on the Cryolophosaurus, and the Mongolian mammals which weren't just shrews or mice.  I also liked the homage to Dryptosaurus and Ceratosaurus artwork in the Cryolophosaurus section (though I don't think they could really stand on their tails, given how most theropod chevrons look).  The Gigantoraptor's feathering was more problematic, as it seemed more like a naked theropod covered in feathers than an actual feathered creature like a bird, where body outlines are hidden and feathers interact and fold.  Its wings were always held out in front, which for a display is fine, but even the female who wanders up is posed this way.  The animation itself was a mixed bag.  Most moved smoothly, but the Saurosuchus looked unnatural for instance.  Similarly, the rendering was good for most, but the therapsids in the opening seen looked plasticy.  What's that you say?  My "good" paragraph's actually mostly full of criticisms?  Guess that prepares the way for the rest of the review...

What made Dinosaur Revolution most difficult to watch is the rampant anthropomorphism.  Basically none of the subjects actually behaves like a reptile, or a bird, or even a non-ape mammal for that matter.  They're chock full of human mannerisms.  You can always tell what they're supposed to be feeling, as if brains that size could even house such emotion.  But it's not just behavior.  My jaw dropped at the blatant 'sexy eyelash' marks on the female Eoraptors.  Why not just go the whole hog and give them real eyelashes they can flutter alluringly?  Then the male's heart (shaped like a heart of course) could project from its chest like a piston.  Would have been almost as realistic as the expectant smile he shows as she approaches in the actual program.  Even ignoring the behavior, the plotlines have so many "entertaining" improbable portions, like the Eoraptor unwittingly throwing a therapsid into Saurosuchus' mouth, that any illusion you're watching reality is destroyed.  And what was up with that swarm of hostile flies chasing the Antarctic fauna and killing the lizard... for blood!  Is this a 1950s horror movie or something?

Which would have all been excusable if the show at least taught us something.  Then it'd be a Dinosaur Train for adults, which wouldn't be my idea of a good program to watch, but would at least educate the part of the public that finds documentaries boring.  But no, I don't think there was any actual paleontological data contained in that hour, besides most of the portrayed anatomy and a few basic facts like "birds are dinosaurs" and "Cryolophosaurus is from Antarctica".  I say "most" because while the models were largely accurate, they sometimes contained some fictional aspect.  The rhamphorhynchoid tail fin on the female Eoraptors, for instance.  Or the highly elaborate wattles and soft horns on the male Gigantoraptor.  And when it comes to behavior, we have bower-building Eoraptors, color flushing Cryolophosaurus which killed the young of rival males, a stomping and twirling Gigantoraptor mating dance, Glacialisaurus which lived in harems (which we so know from the partial hindlimb...), etc.  It's not that these soft parts or behaviors are impossible, but Joe Public's only going to remember Gigantoraptor as "that goofy rainbow-colored thing that dances" or Eoraptor as "those raptors that cutely chirp and build mounds to select mates, and then care for their baby who adorably falls down, awwww".  So you're emphasizing the fictional aspects of these animals, while not going into any of the actual known interesting facts about them.

But maybe the show could have retained some use if all of this human-like/fictional appearance and behavior was there to illustrate some greater true scientific fact, that even network execs think viewers could remember.  Alas, no.  The implication of the Eoraptor portion was that dinosaur success was due to more complex parental care, but my impression has been that evidence for such care is limited to maniraptorans, supposed evidence for care in hadrosaurs (and thus Ornithischia) has been refuted, and that baby sauropods were too small to associate with adults and aren't apparent in herd trackways.  And even the mosasaur cares for its babies enough to get revenge on sharks for eating them (vengeance is such a widespread trait in squamates...).  As does the Cretaceous mammal, more realistically.  If you want to make the point dinosaurs were probably often brightly colored with display structures as the Gigantoraptor portion tries to, a far superior method would be to show say ten different possibilities for a few species in quick succession.  Changing colors and adding wattles wouldn't be that resource intensitive and would get the idea across to laymen without making it seem like we know they had definite soft features and patterns (I'm guessing the Yixian pigments were unknown when this was made).  The Cryolophosaurus portion taught us about the factual behavior... of lions.  The mosasaur segment taught us... er... "a mother's protective instinct is a force of nature than can change the world."  And the Glacialisaurus one taught us "a little bad luck goes a long way."  That's certainly scientific.  Maybe the next episode will teach us "the disadvantaged underdog can succeed with perseverance and faith in himself."  Sigh

To sum up, watch if you like largely accurate-looking dinosaurs acting like humans in zany situations and learning valuable life lessons.  If you want a show that clearly indicates which parts are based on paleontology, shows dinosaurs as they may have been, and teaches you something about them, keep dreaming.

Friday, September 9, 2011

Tehuelchesaurus and how to describe the affinities of a taxon

I've often complained about the tendency for authors to view their most parsimonious cladogram as "the right" tree, such as here and here.  I note that it's usually more helpful to describe how parsimonious different hypotheses are, since while new analyses usually change the topology somewhat, they rarely support relationships that were strongly rejected before.  Carballido et al. (2011) recently redescribed the sauropod Tehuelchesaurus, and in addition to a detailed osteology and several other important discussions, their paper contains a phylogenetic analysis that did things just the way they should.  The analysis (249 characters, 45 taxa) is based on Wilson's (2002) analysis with added data, including numerous newly added macronarians.  Some characters were ordered, taxa which cause polytomies were deleted a posteriori, and Tehuelchesaurus emerged as a basal camarasauromorph sister to Galveosaurus, not a relative of Omeisaurus as originally thought by Rich et al. (1999).  But instead of simply letting the matter rest there, Carballido et al. included the section "Testing Alternative Positions for Tehuelchesaurus."  Music to my ears.  They tested not only the Omeisaurus alternative (9 steps longer), but also positions slightly more (1 step longer) and less (2 steps longer) than Galveosaurus, and noted the character support for all of these.  In addition, the authors wrote the following which basically covers any plausible position-

"Other positions within basal camarasauromorphs (in any position within the Janenschia/Tastavinsaurus clade, as sister taxon to Europasaurus, more basal than Europasaurus, and as sister taxon to Camarasaurus) and as a macronarian outside Camarasauromorpha, but more derived than Haplocanthosaurus, require three additional steps. Placing Tehuelchesaurus as sister taxon of Haplocanthosaurus results in a suboptimal tree four steps longer than the MPTs, and as the most basal macronarian needs even five additional steps. Even more steps are required to place this taxon in the Titanosauriformes (seven additional steps as a basal somphospondyl and eight additional steps as a basal brachiosaurid).

Any position outside Macronaria also results in considerably suboptimal tree lengths. Five additional steps are needed to make Tehuelchesaurus the most basal diplodocoid, but any position within higher diplodocoids results in trees that are at least ten steps longer than the MPTs. Likewise, placing Tehuelchesaurus outside Neosauropoda requires six additional steps, and any placement among basal, nonneosauropodan taxa results in trees at least nine steps longer than the MPTs. Thus, the possibility of a Jurassic Patagonian clade of sauropods, including Patagosaurus and Tehuelchesaurus, can also be rejected, as it requires 12 additional steps."

The paper succeeds in giving you a much clearer idea of Tehuelchesaurus' relationships than any one cladogram could.  Anybody describing a new taxon should follow their example.

Carballido, Rauhut, Pol and Salgado, 2011. Osteology and phylogenetic relationships of Tehuelchesaurus benitezii (Dinosauria, Sauropoda) from the Upper Jurassic of Patagonia. Zoological Journal of the Linnean Society. DOI: 10.1111/j.1096-3642.2011.00723.x