Talk:Physiology of dinosaurs

message: Does anybody know of any research that deals with whether ornithischians had bird-like air sacs?
Philcha 21:21, 9 November 2006 (UTC)
replies: text: <<in this article "dinosaur" means "non-avian dinosaur", since most experts regard birds as a specialised group of dinosaurs.>>
Well duh, that's the definition of "dinosaurs". Birds aren't dinosaurs anymore than the Japanese are Caucasians. Voortle 19:51, 23 November 2006 (UTC)

text: No. In practically all modern scientific literature birds are considered dinosaurs. The definition in no way excludes birds. That's the conservative scientific consensus. John.Conway 12:44, 11 April 2007 (UTC)

text: No, it doesn't.  By that logic, tetrapods could not have evolved from fish, because tetrapods need their ribs to breathe (primitively, at least) while fish don't.  It's asinine. Mokele (talk) 20:55, 1 February 2010 (UTC)
thread_title:  Misc 

message: I think this should be removed because it's pure speculation. In particular  it fails to address the fact that all known early (Triassic) dinosaurs had erect limbs, which implies that they were about as active as mammals and birds of the same size and therefore needed fairly fast metabolisms.Philcha 23:37, 22 December 2006 (UTC)
thread_title:  "some may be warm blooded and some cold" 

message: The citation for Bakker's article in nature is wrong.  Anatomical and Ecological Evidence of Endothermy in Dinosaurs, by Robert T Bakker, was published in  Nature  238, pp 81-85.  His nature 229 article contested the view that apatosaurus/brontosaurus lived underwater.
:Okay, it's fixed. J. Spencer 20:55, 8 March 2007 (UTC)
thread_title:  Bad Bibliography? 

message: :"There are no communities of large, cold-blooded animals to-day, so we have no grounds for assuming that such communities would have higher predator-prey ratios."
The section mis-characterises the debate here. Bakker uses other fossil communities as control trails to calibrate predator/prey ratios. There are criticisms of the p/p argument, but this list isn't a good explanation. John.Conway 12:50, 11 April 2007 (UTC)
replies: text: I'm not sure Bakker did just compare "large" animals, and he certainly didn't just compare dinosaurs with living ecosystems. Ah well, I think I'll do a rewrite of the p/p section myself. People seem strangely uninterested in this article now. —John.Conway 10:15, 10 May 2007 (UTC)
thread_title: Predator/Prey ratios

message: I know I've been a bit of a movaholic recently, but the title of this article is clearly POV. I think we should move it to Physiology of dinosaurs, but I'm open to other suggestions. —John.Conway 16:13, 9 May 2007 (UTC)
replies: text: I like it, with the old name kept as a redirect. J. Spencer 21:01, 9 May 2007 (UTC)
replies: text: I think the topic is large enough to warrant its own article — though it needs a substantial rewrite. Of course, it will still have the summary in the dinosaur article. —John.Conway 08:27, 10 May 2007 (UTC)
thread_title:  Propose to move this article to [[Physiology of dinosaurs]] 

message: I cut the following in the restructure, but we might want to re-include it at some point: —John.Conway 15:27, 25 June 2007 (UTC)
replies: text: Looks good so far; the bulleted history section as a lead was pretty soft, but I think its general ideas could be rehabilitated if we wanted such information back in (perhaps borrowing from Dinosaur and Dinosaur renaissance)?. J. Spencer 15:32, 25 June 2007 (UTC)

text: I think removing these items was a mistake. I'm old enough to remember when everybody just assumed dinos were cold-blooded (and the more active mammals drove them to extinction by eating their eggs); and the history also explains why the debate still is often heated and even acrimonious (you should see some of the comments in the expert forums) - paradigm shifts usually meet fierce resistance. The other stuff about possible mechanisms for maintaining high BMR and homeothermy is important to in order to complete the analysis, particularly the point that gut fermentation and inertial homeothermy were not possible for small dinos and therefore not possible for the earliest dinos.Philcha 23:00, 26 June 2007 (UTC)
replies: text: I'm all for having historical context, but this was just too thin. Having said that, though, there really should be a brief description of attitudes, which could have a robust paragraph for each of the cut historical bullet points, plus a "modern" paragraph saying where we've gone since Bakker and Ostrom. J. Spencer 03:33, 30 June 2007 (UTC)

text: I understand the historical context, but I agree with J. Spencer that the above was too thin -- it just didn't do the job. I also think that something needs to be written, perhaps based on the physiology section of the dinosaur renaissance article. As for debate recently, it's vastly altered to the point of non-existance, and rarely acrimonious. I haven't seen many fights over it on the DML in the last six years (and there's been no shortage of acrimonious debate on other subjects on the DML!). — John.Conway 19:06, 30 June 2007 (UTC)
thread_title:  Stuff cut from article 

message: I threw together a couple of general paragraphs on the early history.  How's the tone?
===Early interpretations of dinosaurs: 1820s to early 1900s===
The study of dinosaurs began in the 1820s in England. Pioneers in the field, such as William Buckland, Gideon Mantell, and Richard Owen, interpreted the first, very fragmentary remains as belonging to large quadrupedal beasts. Their early work can be seen today in the Crystal Palace Dinosaurs, constructed in the 1850s and which present known dinosaurs as elephantine lizard-like reptiles. Despite these reptilian appearances, Owen speculated that dinosaur heart and respiratory systems were more mammal-like than reptile-like.
With the discovery of much more complete skeletons in the western United States, starting in the 1870s, scientists could make more informed interpretations of dinosaur biology.  Edward Drinker Cope, opponent of Othniel Charles Marsh in the Bone Wars, propounded at least some dinosaurs as active and agile, as seen in the painting of two fighting "Laelaps" produced under his direction by Charles R. Knight.Lucas, Spencer G. 2000. Dinosaurs: The Textbook, 3rd, McGraw-Hill Companies, Inc., 3-9.  In parallel, the development of Darwinian evolution, and the discoveries of Archaeopteryx and Compsognathus, led Thomas Henry Huxley to proposed that dinosaurs were closely related to birds. Despite these considerations, the image of dinosaurs as large reptiles had taken root, and most aspects of their paleobiology were interpreted as being typically reptilian for the first half of the twentieth century.
===Changing views and the Dinosaur Renaissance===
However, in the late sixties views began to change. Paleontologist Robert Bakker, in a series of papers in the 70s and 80s, beginning with his 1968 paper The superiority of dinosaurs, Bakker, R.T., 1968, The superiority of dinosaurs, Discovery, v. 3(2), p. 11-22 argued strenuously that dinosaurs were warm-blooded and active animals; capable of sustained periods of high activity. In most of his writings Bakker framed his arguments as new evidence leading to a revival of ideas popular the the late 19th century, frequently referring to an ongoing dinosaur renaissance. He used a variety of anatomical and statistical arguments to defend his case,Bakker, R. T., 1986. The Return of the Dancing Dinosaurs, in Dinosaurs Past and Present, vol. I Edited by S. J. Czerkas and E. C. Olson, Natural History Museum of Los Angeles County, Los AngelesBakker, R. T. (1972). Anatomical and ecological evidence of endothermy in dinosaurs. Nature 238:81-85. the methodology of which was fiercely debated among scientists.R.D.K. Thomas and E.C. Olson (Ed.s), 1980. A Cold Look at the Warm-Blooded Dinosaurs 
These debates sparked interest in new methods for ascertaining the palaeobiology of extinct animals, such as bone histology, which have been successfully applied to determining the growth-rates of many dinosaurs.
Today, it is generally thought that many or perhaps all dinosaurs had higher metabolic rates than living reptiles, but also that the situation is more complex and varied than Bakker originally proposed. For example, while smaller dinosaurs may have been true endotherms, the larger forms could have been inertial homeotherms,Benton, M.J. (2005). Vertebrate Palaeontology. Oxford, 221-223.Paladino, F.V., O'Connor, M.P., and Spotila, J.R., 1990. Metabolism of leatherback turtles, gigantothermy, and thermoregulation of dinosaurs. Nature 344, 858-860 doi:10.1038/344858a0 or many dinosaurs could have had intermediate metabolic rates.Barrick, R.E., Showers. W.J., Fischer, A.G.  1996. Comparison of Thermoregulation of Four Ornithischian Dinosaurs and a Varanid Lizard from the Cretaceous Two Medicine Formation: Evidence from Oxygen Isotopes Palaios, 11:4 295-305 doi:10.2307/3515240
===References===
:I really like most of the new intro, and the references. There are a few bits I think are superfluous, e.g. the mention of Marsh and the Bone Wars, and I think I could make the wording a little briefer and clearer. But it does a great job of showing how there was a debate almost from the start.
:Everything I've read says that Ostrom's analysis of Deinonychus (a.k.a. Velociraptor) was the real beginning of the resurrection of active, agile and possibly warm-blooded dinos - and Bakker was Ostrom's student at the time. The "History" section is so good in other respects that this omission should be rectified.
:I'd like to change the first sub-heading to "Early interpretations of dinosaurs: 1820s to 1950s", because dinos were universally presented as cold-blooded and sluggish from the early 1900s to the end of the 1950s.
:Once the structure has settled, we need to check over the article to reduce redundancies, e.g. at present the first para of the section "Metabolism" recaps the history of the debate.Philcha 09:58, 11 July 2007 (UTC)
replies: text: Good point about Ostrom; he should be in there too. J. Spencer 14:57, 11 July 2007 (UTC)

text: Looks good, stick it in. —John.Conway 16:00, 1 July 2007 (UTC)
replies: text: 'Tis done. J. Spencer 17:09, 1 July 2007 (UTC)
thread_title:  History 

message: :I really like most of the new intro, and the references. There are a few bits I think are superfluous, e.g. the mention of Marsh and the Bone Wars, and I think I could make the wording a little briefer and clearer. But it does a great job of showing how there was a debate almost from the start.
:Everything I've read says that Ostrom's analysis of Deinonychus (a.k.a. Velociraptor) was the real beginning of the resurrection of active, agile and possibly warm-blooded dinos - and Bakker was Ostrom's student at the time. The "History" section is so good in other respects that this omission should be rectified.
:I'd like to change the first sub-heading to "Early interpretations of dinosaurs: 1820s to 1950s", because dinos were universally presented as cold-blooded and sluggish from the early 1900s to the end of the 1950s.
:Once the structure has settled, we need to check over the article to reduce redundancies, e.g. at present the first para of the section "Metabolism" recaps the history of the debate.Philcha 09:58, 11 July 2007 (UTC)
replies: text: Good point about Ostrom; he should be in there too. J. Spencer 14:57, 11 July 2007 (UTC)
thread_title: References

message: I'm much happier with this.  Shall we add it? J. Spencer 15:00, 1 July 2007 (UTC)
replies: text: Looks good, stick it in. —John.Conway 16:00, 1 July 2007 (UTC)
replies: text: 'Tis done. J. Spencer 17:09, 1 July 2007 (UTC)
thread_title: arbitrary break

message: I originally titled this section "Posture and gait", and still think it's a much better title because the evidence and arguments all relate specifically to posture and gait rather than to other features of skeletal anatomy, while soft anatomy is covered in other sections of the article.Philcha 10:16, 11 July 2007 (UTC)
replies: text: I think a postural heading makes more sense at this time than "Anatomical Evidence".  If we were to add to that section, a more general heading would be needed, but the writing covers a more specific topic. J. Spencer 15:03, 11 July 2007 (UTC)
thread_title: Heading "Anatomical Evidence"

message: I've just added this section - the 2nd one that's not mainly about thermoregulation / metabolic rate.
I've also moved "Respiration" before "Metabolism". IMO "Metabolism" should come last because it uses arguments / evidence from the other sections. I'll check to polish up inter-section references. Philcha (talk) 10:33, 20 January 2008 (UTC)
thread_title: Reproductive biology

message: You appear to have specified the wrong reference for ref. 17: RuebenJonesEtAl1998 ... : it is identical to RuebenJonesEtAl1997 (ref. 16)! Smith609 Talk 14:53, 31 May 2008 (UTC)
thread_title:  Faulty reference 

message: I believe this article can be brought up to GA-level is somebody is willing to put a bit of time into referencing the last bits of the article. Nergaal (talk) 02:05, 10 September 2008 (UTC)
thread_title: GAN??

message: This article was originally all about dino metabolism, but now has a fair bit of material about other aspects of dino physiology. The question is whether it's now a good idea to restructure completely so that all topics which are not exclusively about dino metabolism are in separate sections from the "Metabolism" section. The advantages are that somweone who's interested in specifically those aspects can find them easily, and it's easy to add new content under these heading even if it's not related to metabolism. The disadvantage is that the "Metabolism" section would then contain a lot of summaries of preceding content, e.g. "Some analyses of dinosaur respiration favor endothermy while others favour ectothermy. Saurischians had air sacs from a very early stage, and these became more extensive as time progressed. Air sacs are generally regarded as a sign of fast metabosisms. Theropods had well-developed uncinate processes, which suggests they were capable of sustained streuous activity, and therefore probably had high metabolic rates. On the other hand Ruben et al's conclusion that dinosaurs lacked respiratory turbinates have apparently not been seriously challenged, and the lack of such structures to prevent dehydration suggests low resting metabolic rates." I think that would be the longest of the "summaries", but there would have be others, e.g. on food grinding mechanisms in some clades but not others.
Suggestions? -- Philcha (talk) 19:05, 12 September 2008 (UTC)
thread_title: Possible restructure

message: Hi, Dan Gluck, you're probalby right about the day in thwe Mesozoic being < 24 hrs. Can you provide a citation? --Philcha (talk) 09:41, 24 October 2009 (UTC)
thread_title: Polar day

message: Under the "air sac" section in the article, some of the proposed figures are off as to regard to what a dinosaur lung size with a mammal respiratory system. 
Mammal lung size are pretty linear across the range of mammal sizes (from rats to whales), with lungs representing about 1% of the body mass, and tidal volumen 8 to 10 ml/kg.   A 30 dinosaur would have the tidal volume of around 300l.  The amount of air exchanged per breath varies between species - for humans, only 10 to 15% of the total lung volume is exchanged, while whales exchange around 80% of their total lung volume with each breath.  Taking a relatively 20% exchange, the lung size for a 30 ton dinosaur with mammal like lungs would only be 1500l in size.  
Also, the lung size in an avian respiratory system does not tell the entire story.  For avian respiratory system, air sac size also needs to be taken account, and the volume of the air sac is several times greater than the lung.  The combined air sac and lungh volume in birds is usually greater than mammals, which is why you don't see a bird with a weasel like frame.  (For example, a 100 kg ostrich has an air sac volume of 15 liters.  An equivalent sized mammal would only have a lung size of 10 l.)  —Preceding unsigned comment added by 66.51.147.97 (talk) 00:25, 2 April 2010 (UTC)
thread_title:  Mammal lung size calculations in "Air Sac" article off.  

message: Just a note that this article is riddled with 'warm blooded' and 'cold blooded'. These need to be replaced with endothermy and ectothermy throughout. Warm blooded and cold blooded have been defunct terms for at least a couple decades. They certainly don't qualify as lay-language in place of jargon either - they're just plain wrong. An ectotherm is in no way 'cold blooded' (a gigantotherm would be a warm blooded ectotherm, but so is a lizard on a hot rock), and endotherms can go through torpor that leaves them the same temperature as the background environment, so that they're not uniformly 'warm blooded' either. Anyway, just a note that this needs to be done. As it stands large chunks of this article read as if it were taken from an encyclopaedia from 1982 and the terminology needs some serious updating.  — Preceding unsigned comment added by 118.139.76.65 (talk) 04:23, 9 April 2015 (UTC)
thread_title:  Warm and Cold Blooded 

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thread_title:  External links modified 

message: I brought a precision to the preliminary note, but the fact is that I really think that the title of the article should be moved to "Physiology of non-avian dinosaurs".
Who agrees with the above? Kintaro (talk) 14:34, 30 May 2017 (UTC)
replies: text: A glance at the article indicates all dinosaurs, including birds, are covered. Some of the images specifically show birds. FunkMonk (talk) 16:12, 30 May 2017 (UTC)
replies: text: Please, FunkMonk, note that birds are always mentioned in comparison with their extinct relatives, the non-avian dinosaurs. Physiology of birds is a different subject here since the article mainly focuses on the controversies of physiology of NON-AVIAN dinosaurs, this is why a "Preliminary note" was added in the heading of the article and this is why I think the move should be done. Kintaro (talk) 16:50, 30 May 2017 (UTC)
replies: text: If we move it, we will have to specify every time they're mentioned in the text too. Just so someone remembers this in the event. FunkMonk (talk) 17:11, 30 May 2017 (UTC)
replies: text: Mmmmmmmm... ok, let's keep it as it is. Kintaro (talk) 17:19, 30 May 2017 (UTC)

text: Recently many new lines of evidence have been brought to bear on dinosaur 120.28.149.140 (talk) 13:18, 22 November 2023 (UTC)
thread_title:  Accurate title proposed 

message: Saw this article today, which seems pertinent.
*
Peaceray (talk) 16:40, 19 February 2020 (UTC)
thread_title:  Eggshell geochemistry