Talk:Dinosaur size

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I am a little concerned about edits to this article by 71.107.107.4, however I do not know enough about this subject to know where the truth actually lies, or whether terms like "lanky" have context-specific meaning. The reference at the end of the article is too vague to be used as an arbiter. Could someone who knows something about these beasts (a) comment here and (b) cleanup the article as appropriate? Thanks. Nick Levine 12:58, 8 March 2006 (UTC)

71.107.107.4's edits don't make much sense. He switched Spinosaurus and Giganotosaurus, apparently under the (mistaken) impression that the later was longer, but din't bother to correct the size data itself. He added "height" to the article, which is largely meaningless when dealing with these types of animals, and on which little to no published data exists (I can't think of any science papers offhand that include a height estimate, except to the hip). Use of adjectives like lanky and heavy are a little misleading, and redundant with the data provided. If one wishes o know how "lanky" Giganotosaurus was (assuming lanky to mean long and lightweight), just look at its length vs. its wight. Further discussion of that sort of thing should be confined to the species page.


As for the data itself, the estimates by Mortimer are all based on published sizes of specimens and/or individual elements. Since I don't have an extensive library of papers to draw from, I can't say whether or not the *overall* sizes are supported in the literature. If someone has a published source that contradicts one of Mortimer's estiamtes (as in the more recent dal Sasso paper), please modify the data accordingly and add the citation to references.Dinoguy2 14:59, 8 March 2006 (UTC)

Contents

[edit] Size

I don't know about you guys, but I believe height should be in the article. Also THINK of this, if a T-rex and a Spino would fight, they may be just as tall or it's just fantasy, WHAT DO YOU THINK OF THAT!

If you have a scientific source that discusses how tall a species is, y all means use it in the article. You didn't say where you were getting your height numbers from, so how are we supposed to know if they're real or if you made them up?Dinoguy2 20:24, 8 March 2006 (UTC)

Now, does height really matter when it comes to theropod size? Benosaurus 19:29, 2 February 2007 (UTC)

Now why isn't there any information on the sauropods here? 22:09, 12 March 2006 209.103.198.153

I'll add an (at least provisional) list of largest sauropods using Mike taylor's site [1] and the recent DML thread on the subject [2].Dinoguy2 22:39, 12 March 2006 (UTC)
A problem with height of sauropods is that there is considerable doubt that any of them could hold their necks vertically (with the possible exception of relatively short-necked Camarasaurus Cas Liber 03:23, 31 July 2006 (UTC)

There is no info on the ceratopsians here.

I'm not sure if there should or shouldn't be a section for the tallest Theropods here.

Probably not. Height varies with how the dinosaur is standing, and there are very few published height estimates out there.Dinoguy2 19:14, 20 March 2006 (UTC)

I'm a little confused with the recent changes that occured, the lengths of the theropods were changed minerly, but I don't think it was necessary to make that miner of a change.Spinosaur 10:39, 15 April 2006 (UTC)

Well, if we're going to list down to decimals, we might as well list the right ones. I suppose we could round to the nearest whole number, and we'd have to state this in the text.Dinoguy2 19:54, 15 April 2006

I think that some of the sauropod estimates have gone awry.

Argentinosaurus was NOT 22-30 m long, probably 35+ m is more accurate. 66-88 tons. C'mon. 80-100 is more like it.

Cite?Dinoguy2 00:54, 20 October 2006 (UTC)

Here are a few links that cite Argentinosaurus at the dimensions that I gave above.

http://www.miketaylor.org.uk/dino/faq/s-size/records/ http://www.gavinrymill.com/dinosaurs/giants/giants.html http://dml.cmnh.org/2001Jun/msg00665.html

By comparison, only one link cites Argentinosaurus at 22-26 m, 60-88 tons:

http://dml.cmnh.org/2004Sep/msg00086.html

A few days ago, I made a few changes to the "Sauropods" section of this article. For one, the estimates for Argentinosaurus are completely unheard of. 66-88 tons? I don't think so. 22-30 m doesn't sound accurate either. To prove this, all other pages on Wikipedia itself cite Argentinosaurus at around 35 m, and 80-100 tons. External links are given above. Same goes for Paralititan. 32 m is much more likely for a creature that weighs 65-80 tons. The given estimates have sourced from Mortimers article (2004). He gives 28-34 m for Bruhathkayosaurus, 22-26 m for Argentinosaurus, and 20-24 m for Paralititan. The weights of these giants would also be proportionately reduced to 157 t, 73 t, and 56 t. However, while 20-24 m is given for Paralititan, 65-80 tons is the weight estimate give here, whcih is about the weihght of a 32 m long creature. Plus, 28 m is the minimum length estimate for Bruhathkayosaurus, while 44 m is the maximum. Why are the maximum lengths not given for the other sauropods as well. Take Seismosaurus. 32 m is given here, while sources put it as high as 54 m. In short, this entire thing is a mess. I made the necessary changes, but someone changed it back, whcih is vandalism. I hope this stops.

Looking only at the Seismosaurus example, you're right that it was originally claimed to be about 40-50 m long, but this GSA poster made a case that a lot of additional vertebrae were mistakenly assumed to fill a gap between two blocks, when in reality the two blocks may have been adjacent in life and separated after death, making for an animal closer to 32 m long. I haven't seen any replies in the literature that refuted that argument.
Cephal-odd 03:12, 27 October 2006 (UTC)

[edit] Giganotosaurus weight

I realise I don't know as much as everyone else here, but I thought Giganotosaurus was a lot heavier than that. It is certainly listed as being around 9 tons in the Giganotosaurus wikipedia article. If this is inaccurate, shouldn't the Giganotosaur article be amended? If not, then shouldn't its weight in this article be changed? User 130.159.248.1

Thanks for pointing that out. I'll amend the Giganotosaurus article. The thing to remember about carnosaurs is that they were generally more lightly built than tyrannosaurs of the same length.Dinoguy2 15:10, 17 March 2006 (UTC)

Me again. Just noticed that the Carcharodontosaurus article lists Giganotosaurus as having the largest skull of any predatory dinosaur. Shouldn't that be amended as well? I was under the impression from the Spinosaurus page that larger skulls have been found of Spinosaurus. Or does it mean largest most complete skull? User User 130.159.248.1

Yes, it probsbly means largest complete skull.Dinoguy2 19:52, 15 April 2006 (UTC)

[edit] Deinocheirus and Therizinosaurus

Should these two be listed here? Although it's certain they were very large animals, their size consists of vague estimates based on just their arms (which may have been very long in comparison to other theropods', or not). Jerkov 11:42, 8 July 2006 (UTC)

[edit] Thyreophorans vs separate cats for Stegosaurs and Ankylosaurs

How do we feel about this one? (was about to add Stegosaurus but had a thought.....)

Voting?

Separate:

  1. Cas Liber 03:16, 31 July 2006 (UTC)

Together as Thyreophores:

[edit] Dino size, Revert wars, & Unsourced stats

There have been a lot of edits, and reversions of edits, for sauropod lengths and masses. But there still doesn't seem to be a single source about sauropods cited in the article itself. (Some sources have been mentioned in the talk page, although they're mostly websites rather than primary literature.)

It might be best for people to refrain from editing any more sizes until someone can cite a source for them. As I recall, both sets of titanosaur sizes being put forward here have been calculated by paleontologists, with the lesser masses and lengths being perhaps more recent estimates based on more complete remains of smaller titanosaurs. But we need to source our claims.

Cephal-odd 17:18, 29 October 2006 (UTC)

The larger stats are simple do-it-yourself calculations. These can be done based on comparisons with more well known specimens. Argentinosaurus' tibia was 1.55 m long. Brachiosaurus brancia's tibia was 1.15 m long. Using these figures as a basis, 35 m can be calculated for the titanosaur by B. brancia's 26 m length. The more recent, accurate estimates put Brachiosaurus at around 30-35 tons. (1550/1150)^3 gives around 73-85 tons for Argentinosaurs. However, titanosaurs tend to be more heavily built than their cousins, and by multiplying this by a figure of 1.2 giving around 90-100 tons. Using the same methods for Bruhathkayosaurus, we get 44 m, 190-220 tons. Paralititan gives 33 m, and 70-80 tons. Need I say more? Silvertounger

Maybe a bit more . . . The Berlin specimen of Brachiosaurus brancai is a fairly complete skeleton, so at least we know its height and length, and can roughly estimate its mass. But many of the other giant sauropods are known only from a few bones. Scaling up provides a very rough estimate, but the proportions of different genera are likely to be different. Your calculations recognize this by multiplying the weight by a factor of 1.2 for titanosaurs, but not all titanosaurs were identical, so how can we assume they all had the same build? Something as simple as a longer tail or neck can increase the length by several meters, while little increasing the animal's weight. Bigger animals tend to be stockier than smaller ones, so simply cubing the linear ratio may understate mass. We can overlook a lot of unknowns by simply scaling up from a tibia.
Not to say that estimating size is a waste of time. Estimates are good, but we should be cautious, acknowledge a large margin of error, and provide sources both for our numbers and our methods. For example, we could cite references for the size of the Berlin brachiosaur, for the 1.2x scaling factor for titanosaurs, and for the measurements of the bones that we're basing our calculations on.
By the way, in the case where editors are reverting each others numbers, it seems that both groups may be using similar methods to extrapolate lesser known weights from better known weights, but are starting with different values for the latter. For example, one essay, linked in a discussion above, argues that some titanosaur size estimates were too great because they were based on fragmentary material. More recent reconstructions of more complete but relatively small titanosaurs have shown them to be shorter than previously thought. That's why it's useful to state your starting assumptions, so readers can see that our statistics, and statistics revised, are neither revealed secrets nor figments of the imagination. Cheers, Cephal-odd 06:07, 4 November 2006 (UTC)

Since your asking me to cite this, this information was obtained from Mike Taylor. By the way, out of curiosity, what are your estimates for the largest sauropods? Silvertounger

Alas, I'm not a dinosaur specialist, so I've taken no independent measurements of giant sauropods. In the past I have done calculations like those you describe above, to arrive at rough mass estimates over 100 tons for the biggest brachiosaurs and titanosaurs.
The sources I turn to are probably much the same as yours; I like Taylor's site and the Dinosaur Mailing List, because both base their estimates on published data. Gregory S. Paul wrote an elaborate article called "Dinosaur models: the good, the bad, and using them to estimate the mass of dinosaurs", which I've added to the references. It stresses the importance of making a drawing or model that matches the skeleton, since many of the wildly differing mass estimates for Brachiosaurus and other species were based on inaccurate models. These websites made estimates in a similar vein:
As good as these sources are, some of their estimates may be in error because they're based on older calculations of titanosaur size. As I understand it, complete titanosaur remains were unknown until the recent description of Rapetosaurus, and length estimates before its discovery were too great. Titanosaurs too large? is an explanation of the smaller length estimates. That message also links to older messages with prior calculations (although some internal links are broken because of a change of URL - try changing the <http://www.cmnh.org/fun/dinosaur-archive/> part of the path to <http://dml.cmnh.org/>).
Both sites have fine essays discussing the challenge of estimating size from bones:
Anyway, the main reason I suggested citing sources was that some edits would change a bunch of size statistics and essentially say "No way, those old numbers are way off! Here are some better ones." Usually not much support was presented one way or the other, practically inviting the next editor to do the same thing. My quarrel is not so much with the numbers as how they were presented.
Cephal-odd 06:23, 12 November 2006 (UTC)
As the guy who started this page I'm kind of regretting its present state. My opinion now is that we should only be using published sources for these, individually cited. This is beyond my capability to do, at the moment. Unless someone else can find some good published stats to fill in this page (maybe in The Dinosauria?), I'd even nominate the whole thing for deletion.Dinoguy2 00:35, 7 November 2006 (UTC)

Published sources? As in books? That's probably the worst thing you could do, as most books don't contain up to date information.

As in peer-reviwed scientific papers, or technical books like The Dinosauria.Dinoguy2 21:03, 11 November 2006 (UTC)
It would be a shame to lose the whole article to deletion, since dinosaur size is a fascinating topic, and one of the most common things people ask about the beasts. The article could use more context for the numbers, though, instead of the Top 10 List sort of format that seems to have emerged. For instance, maybe instead of precisely ranking the heaviest sauropods, we could list the genera thought to be among the heaviest, the skeletal elements they're known from, and the measurements of those bones.
The Dinosauria would be indeed be a good reference. Journal articles would be ideal, although those are unfortunately inaccessible to most readers. Even links to the more reputable websites would be constructive. I'll work on adding some references, although it will be a gradual process to document all these groups. Cephal-odd 06:37, 12 November 2006 (UTC)

How about we follow Cephal-odd's suggestion, and also add both the old and new sizes for this articles, noting how they vary wildly. Silvertounger

Are we going to decide on a single size or what? Silvertounger

What old and new sizes do you mean? Generally, aren't old sizes going to be more incorrect compared to newer sizes?Dinoguy2 16:34, 26 November 2006 (UTC)


Not neccesarily. Published_ estimates of _Brachiosaurus_ mass include 78 tonnes (Colbert 1962), 15 tonnes (Russell et al. 1980), 47 tonnes (Alexander 1989), 29 tonnes (Anderson et al. 1985), 180 tonnes (for "Ultrasauros") (Norman 1988), 32 tonnes (Paul 1988), 74 tonnes (Gunga et al. 1995), 37 tonnes (Christiansen 1997) and 26 tonnes (Henderson 2003). Isn't the 1988 estimate of 32 tons more accuarate then the 1995 estimate of 74 tons? Actually, I'm not disputing that the old or the new estimates are right or wrong. I simply suggested that we mention both and let the reader decided which is right. Silvertounger

How is the reader to decide which is right, without a detailed discussion of how these estimates were reached? Better to discuss this on the Brachiosaurus (or whatever) article itself. If this page must exist, though, (I think I know how Frankenstein felt ;)), I agree we should include a number of estiamtes, with cites for each one.Dinoguy2 03:34, 2 December 2006 (UTC)

I read this article, and realized the massive 35-m, 180 tonne Ultrasauros was missing! I think it should be added. dinofan33

See Supersaurus for why "Ultrasauros" doesn't really exist.Dinoguy2 15:25, 2 November 2006 (UTC)

[edit] Stegosaurs

Shouldn't there be a section here for Stegosaurs? Benosaurus 16:24, 6 February 2007 (UTC)

It could be with the thyreophorans, which is currently just ankylosaurs. You'd also want to include Dacentrurus, which was of comparable size or larger (ignore the popular press on this one, which for some reason decided it was small). I notice we also have no ornithopds; although they are boring, there are several genera in the 15 m (49 ft) range (Shantungosaurus, Mandschurosaurus, Lambeosaurus laticaudus, Hypsibema/Parrosaurus, maybe one specimen of Edmontosaurus (I'd have to check)...). J. Spencer 16:58, 6 February 2007 (UTC)

[edit] Height

Does height really matter when it comes to Theropod size? Benosaurus 21:15, 9 February 2007 (UTC)

Whether or not it matters (or whether length matters for that matter) is subjective, but it's not constant, since it depends on posture, so it's much less accurate than length. Dinoguy2 03:13, 10 February 2007 (UTC)


[edit] Changes

Epanterias turned out to be nothing more than a large adult Allosaur and Edmarka is smaller than Torvosaurs in both leagth and size. If you don't argee with me than check the articles of Epanterias and Torvosaurs and you will see of your selfsevelsGoodguy667 00:25, 9 April 2007 (UTC)

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