The time has come to recycle this Tet Zoo classic, dating to February 2007 (it's actually one of the oldest of Tet Zoo ver 2 articles). I've updated it a bit and have included new pics - enjoy! [image below from Kaiji anatomical drawings.. read on for discussion].

To begin with, let's get things straight and admit up front that Godzilla is not a real animal, nor was it ever. It's an unfeasibly big late-surviving dinosaur (belonging to the hypothetical taxon Godzillasaurus, according to some), mutated by radiation, with a radioactive heart. Godzilla is virtually impervious to other gigantic monsters, and also to robots, artillery, laser blasts, lava and fire. Not real. Sorry about that. But by posing questions about fictional entities we can still learn stuff, and you may be surprised to learn that Godzilla has, on occasion, been discussed semi-seriously by various biologists and palaeontologists. Ok, that won't surprise you if you already know anything about Godzilla, but what the hey.

A little bit of introduction to Godzilla first. To date, Godzilla - and here I mean the real Godzilla, and not the thing that appeared in the 1998 TriStar movie (known variously among Godzilla fans as Fraudzilla, Deanzilla [after writer/producer Dean Devlin], GINO* or Zilla) - has appeared in over 20 movies, dating from 1954 to the present. If you've seen any of the new films, you'll know that they don't follow on chronologically from their predecessors. The films are still being made, with the latest being Godzilla: Final Wars (2004).

* Godzilla In Name Only [shown below].

The obvious and boring stuff about scaling and bone strength and so on

Godzilla is meant to be something like 100 m tall and between 20,000 and 60,000 tons in weight (his size fluctuates in the various films). Of course lots of people who like doing sums and talking about cubes and so on have used the mathematics of scaling to show why - duh - Godzilla couldn't really walk, stand, or even exist. Michael Dexter presents the arguments here, and also brings in thoughts on blood pressure, circulation and physiology to show that a living Godzilla would variously fall to pieces, tear itself apart, have its organs turn to jelly, explode due to a build-up of internal heat... you get the picture.

I know of two palaeontologists who have made comments on various of Godzilla's physical properties. Jim Farlow, a palaeobiologist based at Indiana University-Purdue University Fort Wayne, speculated in 1998 on the foot size of TriStar's GINO [GINO shown here]. Jim noted that he'd "probably have to log-transform the measurements to get [the data from the toes] onto the same graphs with my other data without scrunching the other points into an indecipherable blur near the origin". He also noted that it might prove difficult to cast even a single Godzilla footprint given grant limitations and the cost of plaster of Paris, silicone or latex rubber. Sadly, Prof Farlow never published his thoughts on this subject and all we have is a message posted to the dinosaur mailing list (here).

Sauropod expert Mike P. Taylor did a bit of science on Godzilla (this time on the original, not on the TriStar creation), but has also - for shame - failed to publish his results. Interested in how much weight can be absorbed by the limb's cartilage pads, and in how big these pads needed to be in sauropods, Mike threw Godzilla into the data set to see what might happen. Godzilla's cartilage disks would not, it seems, hold up under his incredible weight, and we can therefore conclude that a terrestrial biped of Godzilla's size and weight is impossible. Mike included this valuable and surprising [joke] data in his 2005 presentation 'Upper limits on the mass of land animals estimated through the articular area of limb-bone cartilage', and to his annoyance it was the one brief comment on Godzilla that earned a mention of this presentation in a write-up of the respective conference (Jones 2005). An abstract of Mike's presentation exists (Taylor 2005), though it doesn't mention Godzilla, and you can see the presentation for yourself on Mike's website. The relevant slide is shown below. Incidentally, this work pre-dated the recent surge of interest in the biology and mechanics of articular cartilage.

In 2000, a peer-reviewed technical paper on the biology of TriStar's GINO was published in Mathematical Geology by zoologist Per Christiansen. Per is well known for his work on mathematical scaling in dinosaurs, proboscideans, cats and other tetrapods (his homepage is here). Providing a wealth of speculations and inferences about GINO's locomotor abilities, biomechanics and physiology, the article mostly critiques the view that the new Godzilla created for TriStar's 1998 movie is more realistic, from a biological perspective, than the Japanese original (Christiansen 2000). To cut a long story short, Per concluded that TriStar's GINO violated a number of biomechanical rules; in short, the creature is biologically implausible. Not exactly a surprise. His comment that the real Godzilla "is actually much more plausible from a biological perspective" (p. 239) is mostly based on the real Godzilla's massive columnar legs and walking (rather than sprinting) gait.

Indeed, TriStar's GINO did look far more realistic: its horizontal body posture and flexed hindlimbs make it look like a super-gigantic theropod (this despite the fact that it was meant to be a mutated lizard of some sort). Incidentally, the original plan for the TriStar movie was to have a Godzilla that was very much a re-vamped version of the original one: check out this brilliant concept drawing. The TriStar Godzilla also behaves more like an animal than the real Godzilla: it doesn't seem to have a sense of honour, doesn't talk to other monsters, doesn't use martial arts, and doesn't have atomic breath, for example. But given that it's over 120 m long, 90 m tall and weighs over 24,000 tons, yet is slim-legged and slender, able to run at over 300 mph, and capable of leaping over skyscrapers and such, I somehow sense that Devlin, Emmerich and their colleagues were not striving for biomechanical accuracy in creating the new-look monster. Or, at least, let's hope not. Come to think of it, these are the guys that gave us Independence Day: you can judge that movie by its very first line of dialogue.

Actually, the exact size of the TriStar Godzilla is difficult to pin down given that different sizes have been provided by different people associated with the film and, as Per and others have noted, this is a moot point anyway as the animal changes size throughout the film [in the adjacent scene, GINO's foot is way longer than a New York taxi]. This might explain why Godzilla's exact dimensions are curiously absent from my copy of The Official Godzilla Movie Fact Book (Weinberger & Margolis 1998).

Incidentally, the two different godzillas have a battle in Godzilla: Final Wars, set in Sydney of all places. No prizes for guessing who wins. When GINO is destroyed, one of the human characters says "I knew that tuna-eating lizard was useless".

Godzilla's phylogenetic affinities

Based on the conclusions of Japanese palaeontologist Dr Yamane, we 'know' that the original Godzilla from the 1954 movie was a dinosaur, and - according to Carpenter (1998) - it was clearly a theropod. Yes, this is Ken Carpenter, the palaeontologist best known for his work on the armoured ankylosaurs. By inferring certain morphological details, Carpenter concluded that Godzilla must have been a gigantic neoceratosaur related to ceratosaurids and abelisaurs [Carpenter's reconstruction of Godzilla, shown to scale with Tyrannosaurus rex, is shown below; from Carpenter (1998)]. In part this idea comes from the shared derived character of bony scutes growing along the dorsal midline: present in both Godzilla and ceratosaurids, these aren't present in other theropods and were therefore interpreted as a synapomorphy.

And finally.... Godzilla's 'biology'

Little heard of here in the west is the interesting area of Kaiju-biology (Kaiju means monster). To see the sort of thing that kaiju-biologists get up to, visit Kaiju-Biology or "Why Wasn't Bio This Fun in School?" and Kaiji anatomical drawings (please do, you won't regret it). It is said on some Godzilla websites (here for example) that Kenichi Yamane wrote a thesis on Godzilla's biology, focusing in particular on Godzilla's eventual demise (in the 1999 Godzilla vs. Destoroyah) by way of radioactive meltdown. The cutaway pictures used below are - apparently - taken from this thesis. It might not surprise you, however, to find that Yamane is not a real scientist, but one of the main characters of Godzilla vs. Destoroyah. In fact, Yamane is the adopted grandson of the Dr Yamane from the original Godzilla movie of 1954.

The anatomical drawing taken from Kaiji anatomical drawings [shown at very top of article] reveal a few of Godzilla's morphological traits (the pictures originally appeared on modern_fred's kaiju eiga set on Flickr). Godzilla's brain is relatively small. In view of Godzilla's apparent intelligence, this might seem surprising - however, one can make an argument that proportional brain size is a poor proxy for 'intelligence' given that some relatively small-brained animals are still capable of reasonable feats of cognition. The diagram also reveals that Godzilla has large lungs; presumably these enable the storage of large quantities of gas, and hence explain Godzilla's long dive times.

The drawing at top reveals some extreme skeletal weirdness; if accurately depicted, they make Godzilla highly peculiar compared to other tetrapods. He appears to lack connection between the thoracic ribs and the sternum*, possesses a rounded ossification (a sesamoid?) in the elbow region and seems to have fused metacarpals. An elongate, strut-like coracoid (apparently consisting of two, sub-parallel shafts) is weird in being superficially bird-like, and he has a mammal-like patella. Combined with features such as the external pinnae, some of these attributes have at times led workers to wonder if Godzilla might not be a dinosaur or even a reptile at all, but actually "[a] wildly divergent [synapsid] that tried to emulate theropods in [its] own way" (Ramjet 2007). Godzilla's enormous leg muscles are said to be specialised for the support of his gargantuan weight, and a few unique organ systems - the 'uranium sack' and 'nuclear reaction sack' - are visible in the abdominal region. These structures allow the production of radioactive fire-breath, and also energise the body.

* Henry Tsai notes that the artist may simply have not drawn all of the ribcage in order to reveal the viscera. Good point.

It what might be a minor inconsistency in anatomical interpretation, the proposal has also been made that Godzilla generates radioactivity by way of a drastically modified stomach, now termed the plasma gland. Radioactive particles emerge from the gland and are expelled via the mouth during combat: excess radioactivity is passed into the dorsal scutes at the same time "not unlike the overflow guard in your ordinary bathtub", apparently (according to this source: this is where the image used above comes from). Thanks to its plasma gland, Godzilla continually generates new radioactivity as a source of power, discharging the excess via the scutes and a duct leading to the mouth. This also means that Godzilla doesn't need to eat: surely a good thing when you weigh over 24,000 tons. I don't think that Godzilla can possess a 'uranium sack' and 'nuclear reaction sack' and a plasma gland, so these interpretations are indeed inconsistent. This merely highlights the difficultly inherent in understanding and studying the anatomy of such a massive creature. Remember that many details of elephant anatomy remain mysterious!

Other interesting speculations have been made about Godzilla's biology, including on his cell structure, and on the mysterious substance known as Regenerator G-1. This provides him with unparalleled regenerative abilities. Clearly, there is much to learn about the biology and anatomy of this most remarkable of kaiju.

The original article appeared here. For other Tet Zoo articles on speculative zoology, see...

Refs - -

Carpenter, K. 1998. A dinosaur paleontologist's view of Godzilla. In Lees, J. D. & Cerasini, M. (eds) The Official Godzilla Compendium. Random House (New York), pp. 102-106.

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

Jones, D. 2005. Meeting reports: Progressive Palaeontology 2005. The Palaeontological Association Newsletter 59, 77-79.

Ramjet, N. 2007. Comment 337667 on 'The Science of Godzilla'. Tetrapod Zoology.

Taylor, M. P. 2005. Upper limits on the mass of land animals estimated through the articular area of limb-bone cartilage. In Anon. (ed.) Conference programme and abstracts: Progressive Palaeontology 2005, University of Leicester, 15-16 June, p. 18.

Weinberger, K. & Margolis, D. 1998. The Official Godzilla Movie Fact Book. Puffin Books, London.