The anatomy of Zilla, the TriStar 'Godzilla'

I recently posted an updated version of the 'Science of Godzilla' article, and what a great success it was. But I'm kicking myself, because I totally forgot something else I should have mentioned: Tracy L. Ford recently had cause to produce a number of anatomical drawings of Zilla (aka GINO*/Deanzilla/Fraudzilla), the monster bipedal reptile that invades New York in the 1998 TriStar movie Godzilla. Like all Godzilla fans, I don't regard Zilla as a 'Godzilla' at all; rather, it's a charlatan, an imposter. And the movie itself is awful.


* Godzilla In Name Only

Anyway, Tracy has been kind enough to let me use his drawings here. Here they are, with a bit of commentary.

We begin with a full skeletal reconstruction (and anatomical life drawing) of the creature. In the skeleton, note that Tracy has provided Zilla with a pelvis where both the pubis and ischium are relatively short: indeed, Zilla's body and pelvic region is not particularly deep, so it cannot have had long-shafted, rod-like pubes and ischia like those present in theropod dinosaurs. Tracy has also given Zilla a lizard-like, fenestrated scapulocoracoid. We don't know whether Zilla has gastralia or not: if it is a mutated lizard (see below), the presence of inscriptional ribs incorporated into the abdominal musculature would be predicted.

The gracile, slender-shafted hindlimb bones of Zilla appear somewhat surprising in view of Zilla's incredible size (unwards of 20,000 tons): you might predict that there would be large trochanters for hypertrophied musculature, expanded articular ends, or much thicker bone shafts... but no. The gracility of Zilla is, indeed, a bit of a paradox (Christiansen 2000).

Note in the life drawing that Zilla has pronated forelimbs where the radius is medially positioned and the palms face the ground. This configuration is most likely present because the designers looked at old illustrations of theropods.


Zilla's dorsal armour is undeniably similar to that of the true Godzilla. Note in Tracy's illustrations that there are several parallel rows of osteoderms, extending from the pectoral region to the end of the tail. Transversely-arranged, flat scutes and lateral rows of smaller scutes cover the dorsal surface of the neck.

Zilla's identity is somewhat obscure. It's implied in the movie that it's a mutated giant lizard (perhaps a marine iguana... which would explain why Zilla originated in the south Pacific* and eats fish**), and a mutated giant lizard only superficially similar to theropod dinosaurs. Zilla's feet don't make much sense in that the hallux (digit I) is absent, while the small, divergent digit is digit V (the one on the outside edge of the foot). I reckon that the designers looked at theropod feet, but then 'flipped' the foot anatomy in order that Zilla didn't look precisely like a theropod. You can see from Tracy's drawings of the hand that Zilla has a divergent thumb, in which case it's superficially similar to theropods and different from lizards.

* Given that marine iguanas only live on the Galapagos Islands.
** Given that marine iguanas are strict herbivores.


Finally, we come to cranial anatomy. Zilla's massive lower jaw and protruding chin region are peculiar and anatomically novel, and perhaps incongruous with its diet of fish: you might regard its head as 'over designed', or perhaps the result of a hormonal imbalance. Indeed, the creature proves to be a parthenogenetic female, pregnant with a clutch of several hundred eggs, so something freaky is going in hormonal terms (Zilla's parthenogenetic ability is at least consistent with a squamate identity: e.g., Maslin 1971, Lenk et al. 2005, Watts et al. 2006). The laterally positioned nostril and eye don't appear at all consistent with Zilla's amphibious/semi-aquatic lifestyle, but then neither do any other of its characteristics. It looks about as aquatic as a psittacosaur (ha ha - - an in-joke).



Above is Tracy's take on the skull. That massive coronoid process is consistent with a very powerful bite. The fact that the tooth crowns appear borne on bony pedicels is peculiar and makes it looks as if the dentition is acrodont (where sockets or an anchoring groove are absent, and where the teeth are fused to the jaw bones), but...


... as you can see here, the teeth are very long-rooted and hence the dentition must in fact be thecodont (where the teeth implant in deep sockets). Tracy surmises that canals in the tooth crowns are connected via ducts to specialised labial glands.

To my knowledge, none of this has been published, though I believe it did form the topic of a conference presentation. The skeleton anatomy of Zilla is evidently quite well known (arguably more so than that of the real Godzilla), though no information is yet available on its internal soft-tissue anatomy. I hope you enjoyed this additional excursion into monster anatomy, and many thanks indeed to Tracy Ford for allowing use of his illustrations.

For other Tet Zoo articles on speculative zoology, see...

Refs - -

Christiansen, P. 2000. Godzilla from a zoological perspective. Mathematical Geology 32, 231-245.

Lenk, P., Eidenmueller, B., Staudter, H., Wicker, R. & Wink, M. 2005. A parthenogenetic Varanus. Amphibia-Reptilia 26, 507-514.

Maslin, T. P. 1971. Parthenogenesis in reptiles. American Zoologist 11, 361-380.

Watts, P. C., Buley, K. R., Sanderson, S., Boardman, W., Ciofi, C. & Gibson, R. 2006. Parthenogenesis in Komodo dragons. Nature 444, 1021-1022.

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the movie itself is awful

Indeed, but 'Zilla' herself isn't its biggest problem. Who the hell thought it would be a good idea to cast Matthew Broderick as the male lead in an action movie? If Arnold Schwarzenegger had been there hamming it up instead, the movie might at least have had a chance of ending up in the 'So Bad It's Good' category.

perhaps a marine iguana... which would explain why Zilla originated in the south Pacific

On biogeographical grounds, isn't some kind of Brachylophus-like Pacific island iguana a more likely candidate?

superficially similar to theropod dinosaurs

When looking at those 'Zilla' drawings, I am actually more reminded of reconstructions of rauisuchids (including the Postosuchus from Walking With Dinosaurs).

Hmmm...that "50 m" scale bar can't be right can it? That would seem to suggest that GINO was around 1200 - 1500 ft tall and roughly 2000 ft long?

The teeth and their strange pedicels remind me of mosasaurs.

It looks about as aquatic as a psittacosaur (ha ha - - an in-joke).

Please do explain!

By David MarjanoviÄ (not verified) on 19 Nov 2010 #permalink

Hmmm...that "50 m" scale bar can't be right[,] can it?

If the scale bar is right, GINO is 300 m tall. Like the Eiffel Tower. Doesn't that sound right?

By David MarjanoviÄ (not verified) on 19 Nov 2010 #permalink

For clarification on the drawings. I did them for a talk I gave at the Godzilla convention that was held in Burbank a decade ago (I think). Mike Fredricks asked me if I could give a talk. I actually gave two; one on the 'new' Godzilla (because there was just one verison of it and it was easy) and the other on the biggest dinosaurs. Out of the two talks I had about 6 people. I gave the talks anyway. Only the head reconstruction was ever published. It was in the Godzilla Magazine.

By Tracy Ford (not verified) on 19 Nov 2010 #permalink

@ David
300 m - is that how tall GINO is supposed to be? I'm not familiar with his specs but he didn't appear that large to me when I saw the movie. For example, he seemed a good bit shorter than most of the buildings he ran past or hid behind. If he was really 300 m tall then he would have been substantially taller than all but a handful of buildings in Manhattan. To me GINO looked roughly the same size as the original Godzilla which would have put him somewhere around 100 m in height.

This cannot be a reptile, giving complete absence of coolness, which even Fiji iguanas possess.

Better take on graboids!

I can't speak to the science of it, but yes, the Devlin/Emmerich Godzilla was a vast disappointment.
I will say that the animated series that followed at
least took a stab at making Godzilla more like Godzilla.
( He/She got the true atomic breath and many other monsters to fight. ) worth seeking out, if you like monsters.
GINO works only slightly better if you consider it more
a re-make/sequel to The Beast From 20,000 Fathoms,
the Ray Harryhausen classic that (Probably) inspired
Godzilla.( And Darren's comments on the "Rhedosaurus"
would be welcome.)

By Craig York (not verified) on 19 Nov 2010 #permalink

@David Marjanovic: About the psittacosaur thing, Tracy published a paper in the ceratopsian volume suggesting that Psittacosaurus was semi-aquatic. I posted a lengthy critique on my own blog of that theory, and then I hosted his lengthy response. Then I responded again. Good times!

I would think that the simplest explanation is that this was a commissioned work, and that the God of Evolution was having a bit of an off day. Rejecting his plans for giant beetles, or a more efficient wheeled locomotion system would probably not have put him in too good a mood, hence the rush-job on this one.

By Dan Holdsworth (not verified) on 19 Nov 2010 #permalink

It's implied in the movie that it's a mutated giant lizard

The ominous music playing over footage of marine iguanas was one of the narmiest things I've ever seen, and I frequently watch MST3K-caliber films.

If the scale bar is right, GINO is 300 m tall. Like the Eiffel Tower. Doesn't that sound right?

Nope, according to Godzilla Wiki the canonical height is only 55-84 meters. IIRC the foot was as long as a city bus, not a fleet of them!

Ugh, Zilla. He appropriately gets DESTROYED in .2 seconds by the Real Godzilla in the movie Godzilla: Final Wars :>

I thought it was also funny that Zilla was all crappy CGI. Hahaha.

Aside from the odd loss of pedal digit 1, the phalangeal formulae of both manus (2-3-3-3-1) and pes (0-4-4-4-2) are weird. Is there another tetrapod anywhere like that? For the manus, mammals come closest. For the pes?? I'm pretty sure no squamate is at all similar.

(Barney, incidentally, is confusing, as his external anatomy points toward two and three digits in the manus and pes, respectively, but internally he displays pronounced syndactyly, with four fused digits contributing to anatomical digit II in the manus, with an internal mammalian formula. Syndactyly in the pes is less clearcut, but he again has the mammalian formula for skeletal digits.)

By John Harshman (not verified) on 19 Nov 2010 #permalink

I think the thing we're overlooking here is "aquatic gorgonopsids".
*nods knowingly*

By Marcus Good (not verified) on 19 Nov 2010 #permalink

The "So bad it's good" highlight of the 1998 "Godzilla" film came when the Apache Attack Helicopters fired Sidewinder heat seeking missiles at GINO, and instead had the missiles impact on the Chrysler Building due to the fact that GINO, being cold blooded, isn't hot enough for the missiles to lock onto.


Why use Sidewinders? Why not use Hellfire Anti Tank Missiles, with vastly more powerful warheads, which were designed for use against ground targets?

And, moreover, surely a creature as massive as GINO would be a text book bulk homeotherm? He would be red hot to any kind of Heat Seeking Sensor!

And if his body really was that low (The scriptwriters seem to take the phrase "Cold Blooded" literally) wouldn't he have collapsed into a hypothermic coma even before the film started, and saved everyone a great deal of trouble?

Rant over!

You're all right about the size. Thanks for the link to the video; this one is a lot better because it isn't all pitch black.

By David MarjanoviÄ (not verified) on 20 Nov 2010 #permalink

11: I've always thought that it seemed more like a 20,000 Fathoms remake than a Godzilla movie.

18: Another highlight of that scene was how the helicopter pilots helpfully just flew horizontally away from GINO, so it could more conveniently chase after them and run them down.

You know, as opposed to just flying UP and out of its reach.

By Bootstrap (not verified) on 20 Nov 2010 #permalink

The iguanian lizard with the most reduced phalangeal formula(e) would be Moloch horridus, which varies from (manus/pes) down to (Greer 1989, The Biology and Evolution of Australian lizards). Phalangeal reduction is not seen in any of the more cursorial and partly bipedal members of the group.

The teeth look mosasaurian, and that chin does remind me of a couple of lizards, though only pareiasaurs and gorgonopsians actually get close. Mark Hutchinson and I described a large Plio-Pleistocene skink jaw from Wellington Caves that had a pretty massive symphysis, and at one point he suggested a name referencing Dudley Do-Right.

But I have a possible ancestor of Zilla right here: a late Oligocene 'water dragon' (referable to Physignathus in the obviously paraphyletic sense including the type P. cocincinus and also the Australian P. lesueurii, shown genetically to be closer to the amphibolurine clade) that has an unusually tall snout and massive mandible. There've been plenty of instances of Australian reptiles dispersing to and flourishing on islands in the south-west Pacific (mekosuchine crocs, meiolaniid turtles, Eugongylus-group skinks, carphodactyline geckoes).

I'm not sure if I should propose a relationship to Zilla in the official description, what do you think?

Darren: Please note new email address.

By John Scanlon, FCD (not verified) on 20 Nov 2010 #permalink

"The biggest problem with that movie isn't Broderick, it's NYC. Godzilla attacks Tokoyo. End of discussion."
There's some pretty good Godzilla novels where he shows up all over the place, actually. Some pretty good monster battles in those things, too.

"I will say that the animated series that followed at
least took a stab at making Godzilla more like Godzilla."
I've heard that the Godzilla from that series is actually recognized as "Godzilla" by Japan...

gorgonopsians actually get close

Hear, hear.

I'm not sure if I should propose a relationship to Zilla in the official description, what do you think?

Yessssssssss!!! Hide it in the acknowledgments or something if necessary, but do it.

By David MarjanoviÄ (not verified) on 20 Nov 2010 #permalink


I'm not sure if I should propose a relationship to Zilla in the official description, what do you think?

Hmm, I can understand (and would approve of) paying homage to the original Godzilla, but do you really want to give that kind of positive publicity to the 1998 movie?

John: I think it's a nice idea; you could come up with a creative etymology (perhaps something that mean 'genuine little dead GINO' or something like that). And you'll note that there are genuine semi-technical references that you can cite when alluding to a relationship with GINO (e.g., Christiansen 2000, as per above). By the way... experience tells me that you can sometimes (depending on journal) cite blog posts in technical articles. Just sayin'. Anyway: hey, I'm no media whore (cough cough), but it's the sort of thing that might guarantee a bit of publicity. And definitely a write-up on Tet Zoo :)

@kad: 300 m - is that how tall GINO is supposed to be? I'm not familiar with his specs but he didn't appear that large to me when I saw the movie.

She didn't appear to have a consistent size in the movie. I'm thinking especially of the scenes in the subway; there's one where Zilla's eye is as big around as a pedestrian tunnel, but later she crawls through a subway tunnel that isn't much larger.