Talk:Brachiosaurus

Brachiosaurid teeth misunderstood

I believe Hallett & Wedel’s (2016) statements on brachiosaurid teeth have been misunderstood.

The information on the teeth of Brachiosaurus is misleading. In the Wikipedia page, it states “As the teeth were not spoon-shaped as with earlier sauropods but of the compressed cone-chisel type, a precision-shear bite was employed.”

This is simply wrong, as Hallett & Wedel (2016) were referring to the latter two titanosauriform groups mentioned; bsomphospondylans and titanosaurs (brachiosaurids being the first of three titanosauriform groups mentioned).

This is further confirmed elsewhere in the book where it is stated “Brachiosaurus often had extremely large nares and spoon-shaped or chisel-like teeth for cropping large quantities of browse in single bites”.

It is also stated by Hallett & Wedel (2016): “Brachiosaurid teeth, although somewhat spoon-shaped like camarasaurs’, are longer, end in chisel like tips and are set in a mouth that’s proportionately wide in relation to length. These produce a more precise form of cutting or shearing, and even though their teeth are specialized, brachiosaurids can crop huge amounts of their preferred browse.”

So considering that the authors were not actually referring to brachiosaurids when it comes to the “compressed cone-chisel type”, and Brachiosaurus is clearly stated to have possessed spoon-shaped teeth in multiple areas throughout the book, it seems appropriate to update the article accordingly and perhaps describe Brachiosaurus teeth to have been “somewhat spoon-shaped and chisel-like”.

I have already edited the page accordingly based on what I’ve explained above. — Preceding unsigned comment added by SciencePublisher (talk • contribs) 07:28, 13 April 2022 (UTC)

Not sure who wrote that, but sure, feel free to modify anything you find incorrect, and very nice you bring attention to it on the talk page too. FunkMonk (talk) 12:28, 14 April 2022 (UTC)

Sorry to be adding such a late reply, but for what it's worth, the term "compressed cone-chisel-like" for teeth was specifically coined to refer to brachiosaurid teeth by Calvo (1994), and as far as I am aware the term (when used at all) is still generally used in that way. Ornithopsis (talk) 00:23, 1 April 2023 (UTC)

Yeah, the original wording that was used clearly said brachiosaurids did not have spoon shaped teeth, which is false. I checked out Calvo (1994), and although yes it is described as compressed, conical, and chisel shaped teeth, other studies have recognised brachiosaurid teeth as also being somewhat spoon shaped, take for example Weishampel et al. (1990). More recent analyses that take into account a broader spectrum of genera have also defined it in a similar way. So I think all these descriptions are equally as important and all represent typical brachiosaurid teeth characters. However, outright stating brachiosaurid teeth to not be spoon shaped as was previously said is just wrong. And considering Hallett & Wedel (2016) were specifically referring to the teeth of Brachiosaurus itself and not to the general family Brachiosauridae like these other studies, I think the current description is sufficient. Mat~1238 (talk) 20:21, 14 July 2023 (UTC)

How appropriate & reliable are Benson et al.'s papers on dinosaur body mass estimate?

By his papers' results, the body mass of some dinosaurs surpass the original size estimate to too much of a greater extent. Accordingly, Triceratops weighs 13~14 metric tons (much higher than the initial estimate) and Iguanodon reaches 15 metric tons (no study has ever published Iguanodon body mass up to this size; they weighed either about or more than 3~4 metric tons according to most studies). Furthermore, initally (in 2014) this 15 metric ton estimate for Iguanodon was based on I. bernissartensis, but he later contradicted himself in the 2018 study showing that this estimate is based on I. seelyi which has disputes on its validity; yes, I'm aware that many scientists think this species belong to I. bernissartensis but then why did he use a different name only after 4 years? Also, as far as I'm aware of, these estimates aren't even based on specific specimens, so I don't think we can even be sure if they were appropriate and reliable size estimates. Junsik1223 (talk) 06:03, 23 July 2022 (UTC)

Well the weight estimates for Brachiosaurus in particular has ranged from as little as 28.3 metric tons (Seebacher, 2001) to as much as 58 metric tons according to the second of Benson's studies. So for such a range in weight estimates based on several different methods, there is no average weight found from study to study. At least with estimates of Iguanodon you are able to derive a weight of 3-4 metric tons according to most studies; for Brachiosaurus there is no average weight to reflect on from "most studies". In fact, over the years the weight estimates of Brachiosaurus appears to have consistently been raised and lowered significantly, from 28 metric tons by Seebacher, to 35 metric tons by Paul (1988) to 44 metric tons by Foster (2003), back down to around 29 metric tons by Taylor (2009), and then raised quite significantly by Benson at 56 metric tons (2014) to 58 metric tons (2018). So reflecting off this research we find quite scattered estimates. Although we do find Seebacher and Taylor in close agreement at 28-29 metric tons. In contrast, we see Benson's (2018) estimate at around 30 metric tons more than what Seebacher and Taylor find. So in conclusion I think it all comes down to figuring out what weight estimating method has proven to be most reliable and comparing that to the methods used in these studies rather than trying to figure out which studies have found similar results to each other (like I said the results of these studies are quite scattered and the only two studies that yield similar results are Seebacher and Taylor). I also must assume the latest study would have derived their estimate based on the latest reconstruction of Brachiosaurus which includes every specimen found to date. But I can't say this for certain, it just would make most sense.

SciencePublisher (talk) 06:51, 30 March 2023 (UTC)

Inconsistency with image descriptions

The photograph showing Riggs and another individual working on the holotype specimen of Brachiosaurus is described to include J. B. Abbott working on the left side. But when you click on more details, another description beneath the summary section refers to the man as H. W. Menke. How could we verify who it actually is? The photo (taken inside of the Field Museum in Chicago) also describes the date as being from 1899 which is impossible since the holotype bones were not taken to Chicago until September 1900. Mat~1238 (talk) 15:54, 8 May 2024 (UTC)

Perhaps MWAK has dived deeper into this? FunkMonk (talk) 17:19, 8 May 2024 (UTC)

Well, in the Brinkman book that identified Menke in the famous picture with the femur this man was merely indicated as "an assistant". He also seemed to be clearly a different person. So I searched for images of possible assistants at the time and found this one: https://explore.chicagocollections.org/image/chicagohistory/71/0863f7n/ leaving little doubt it was indeed John B. Abbott.--MWAK (talk) 17:59, 9 May 2024 (UTC)

Here, another image: https://www.bridgemanimages.com/en/noartistknown/dr-j-b-abbott-prepared-fossils-of-dinosaurs-thigh-bones-for-public-display-at-the-field-museum-the/black-and-white-photograph/asset/2925121 --MWAK (talk) 18:09, 9 May 2024 (UTC)

And here we learn that he had indeed been employed by the museum since 1901, dying in 1935: https://www.biodiversitylibrary.org/partpdf/350952 --MWAK (talk) 18:39, 9 May 2024 (UTC)

And we have these two ourselves.

Less useful.--MWAK (talk) 18:52, 9 May 2024 (UTC)

Since we cannot be 100% sure, should we change the caption to "Riggs (right) and a field assistant (probably J. B. Abbott)" to indicate some degree of uncertainty? Also, I wonder if we need to worry about WP:OR here with this detective work, but I don't know to what degree this applies to image captions (we seem to have more freedom when it comes to images). But if there are concerns, an alternative could be to just write "Riggs (right) and a field assistant". Another thing, as mentioned by Mat above, what do we do about the apparent mismatch of the year (1899) indicated in the caption and the article text that says that preparation began only in the fall of 1900? Maybe we should just remove the year from the image caption? --Jens Lallensack (talk) 19:29, 9 May 2024 (UTC)

Well, we do know from Riggs (1904) that J. B. Abbott had prepared the vertebrae of the holotype during the winter of 1904. I do think it is most likely him in the photo.

The exact year is difficult to determine. My initial guess was sometime during September or later in the fall of 1900, as Riggs apparently began working on the bones (particularly the limb bones) basically immediately after returning to Chicago. But if Abbott actually was not employed at the museum until 1901, it may have been taken early that year. The original field museum archives is also not very helpful, only describing the photo briefly as "Preparing Dinosaurs for Exhibition". I suggest removing the year altogether for now at least. I also probably wouldn't refer to him as a field assistant (that would be more suited to Menke) but instead some kind of laboratory assistant. Maybe something like this:

E. S. Riggs (right) and an assistant (probably J. B. Abbott) working on the holotype material at the Field Museum in Chicago. Mat~1238 (talk) 23:00, 9 May 2024 (UTC)

We might indicate 1901 in a foot note.--MWAK (talk) 05:25, 10 May 2024 (UTC)