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Archive 1 | ← | Archive 4 | Archive 5 | Archive 6 | Archive 7 | Archive 8 | → | Archive 10 |
To preserve the intelligibility of conversation here I have once again moved older discussions on this page to the archive (Archive 5 linked just above). Killdevil 18:30, 19 August 2006 (UTC)
Killdevil -> I somewhat shrunk this section because I find it is becoming rather long and messy: it looks like a list of unrelated news events which have been independently added each time a fresh research news was available. In my opinion this section should be rewritten in a more concise way and the detailed information should be found on separate pages such as Feathered dinosaurs or Dinosaur-bird connection. (Currently, whole paragraphs are duplicated with some inconsistencies). So in short: I did not delete information but moved it to more specialized pages. -- Ollivier 17:29, 1 September 2006 (UTC)
Some bits of text I have some problems with:
I checked the refs and altered the numbers and ranks accordingly because in the state above it doesn't make much sense regarding my knowledge of the subject.
I was under the impression that the skeletons accumulated over time. IIRC there were at least two levels of skeletons in the Bernissart coal mine. After a bit of searching I found this pertinent article:
The meat of it is in French so I'll have to work a bit disentangling the relevant bits of text. I can tell one thing for sure: It wasn't a ravine where the Iguanodon fell but one of the many sinkholes existing in the area at the time. Come to think of it, it stands to reason it should be so, as usually a ravine has a way out: downstream.
I'm pretty sure Lagosuchus isn't a dinosaur, though a dinosauriform, and not even a particularly well defined genus. Barring the likely chance "dinosaur" is being used a shorthand for anything ornithodiran more closely related to Dinosauria I'd propose Marasuchus for the place and that it'd be stated that it is a close relative of dinosaurs.
Oh and let it be know that the edit made on the article by User:193.136.225.26 is mine and that it is related with this post. I like to preview a lot and I do have to go to the men's room on occasion ;P Dracontes 10:01, 18 September 2006 (UTC)
It also fails to account for how the animals in question, sauropods, would regulate their temperature before they got to that size in the first place, IMHO, as they did start quite small. Dracontes 15:37, 2 March 2007 (UTC)
Both of these groups are theropods. Both are classed as their own distinct lineages. Yet both contained feathered representatives. And it is almost (though not entirely) certain that feathers evolved only once. What gives?. Do the feathered creatures fall under one clade or the other?. - 03:31, 24 September 2006 (UTC)
I'm still waiting for an answer. I expected this page to have higher web traffic. Anybody reading this, please leave at-least a comment. - 01:33, 29 September 2006 (UTC)
Correct me if I am wrong, but last I heard Alvarezsaurs were classed as ceratosaurs. - 15:59, 29 September 2006 (UTC)
Of course I could be wrong; that was a long time ago, on an old book. I would have to check the Ceratosaur clade once more. - 16:04, 29 September 2006 (UTC)
As far as I know, alvarezsaurs are not considered ceratosaurs anymore. Either they appear as birds in cladistic analyses, or as more basal theropods, but always within Coelurosauria (sometimes close to ornithomimids). -- Ollivier 21:06, 30 September 2006 (UTC)
OK. I can't remember any other potentially feathered ceratosaurs. I guess that answers my question. - 21:52, 30 September 2006 (UTC)
Re erect limbs (under "Other shared anatomical features"), reptiles with sprawling limbs can move about as fast as similar-sized mammals with erect limbs. The main advantage of erect limbs is that they eliminate Carrier's Constraint (new article needed), so that the animal can breathe efficiently while moving. This gives animals with erect limbs greater stamina than animals with sprawling limbs.
Re dino metabolism, a lot of the bone structure and soft tissue evidence is ambiguous and / or disputed. For example some of the bone structre features are found in a few cold-bloded reptiles and not in some mammals. And the specialist paleontology sites are full of debates about whether some fossilised features represent e.g. 4-chambered hearts or just artefacts of the fossilisation process.
In my opinion the best arguments for "warm-blooded" dinos (i.e. metabolic rate comparable to that of mammals of similar size) are:
Sprawling limbs are efficient for a creature that spens most of its time flopped on its belly and only moves for a few seconds at a time, because they minimise the costs of getting up and lying down but make the animal subject to Carrier's Constraint. Erect limbs are the opposite - they avoid Carrier's Constraint, but increase the costs of of getting up and lying down (in mammals, which mostly have very flexible backbones, they also pump the lungs when running; but most dinos had short rigid backbones, like birds, so would not have enjoyed this additional advantage) - so erect limbs are a disadvantage for a sluggish animal and an advantage for an active animal. In addition, dinos were fundamentally bipeds, and bipedalism makes getting up even more laborious as it removes the option to get up one end at a time (as cows do). So I think erect limbs + bipedalism indicates an active lifestyle and high metabolic rate.
Dino fossils have been found in areas which were within the Antarctic Circle during the Mesozoic and show signs of having had regular frosts. Cold-blooded reptiles can only survive frost by burrowing and hibernating, but the fossil dinos were fairly large by modern standards and we've found no evidence of burrowing dinos. So it appears dinos could generate adequate heat in these conditions, which indicates a high metabolic rate.
Studies of T Rex' lifecycle (e.g. http://www.bioedonline.org/news/news.cfm?art=1067, http://www-geology.ucdavis.edu/~cowen/HistoryofLife/CH12.html, http://www.naturalhistorymag.com/0505/0505_feature.html, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15347508&query_hl=1) indicate that it grew in 3 stages: (a) slow growth up to 1 ton weight at about age 10; (b) rapid growth to 5-7 tons at about age 16, an average increase of a ton per year(!); (c) negligible growth after that. Stage (b) indicates a fast metabolism - compare with crocs, which take 15 years to reach sexual maturity and a lot longer to reach full size. I've seen no growth timescales for sauropods, but I've seen many arguments that they would have had to grow fast (at least at some stage), as their eggs range in size between a large melon and a basketball and most sauropods reached 30 to over 100 tons at maturity depending on species.
I've also just seen a paper ( http://palaeo-electronica.org/1999_2/gigan/discus.htm) which argues that oxygen isotope ratios in the bones of adult T Rex and Giganotosaurus indicate a rapid metabolism but that this was achieved by inertial homeothermy (because distal bones show "cooler" isotope ratios). So it would be interesting to see whether there have been similar studies on smaller dinos (e.g. Velociraptor, ornithomimids). And of course inertial homeothermy would not have worked for juvenile dinos.
Wkipedia ought also to reference http://wiki.cotch.net/index.php?title=A_Reply_to_Ruben_on_Theropod_Physiology&printable=yes. This paper summarises and criticses Ruben's argument that dinos lacked respiratory conchae (aka nasal turbinates), which since its publication in 1996 has been one of the most-quoted reasons for believing that dinos were ectothermic.
Philcha 17:47, 5 October 2006 (UTC)
Just found http://www.physorg.com/news73665780.html, in which the researchers say that their lifecycle data on Albertosaurs does not suggest super-fast growth in the teenage years.
BTW I also wrote the last post ("Erect gait; metabolism"), but forgot to sign it.
Philcha 18:01, 5 October 2006 (UTC)
The article wrongly says "Dinosaur synapomorphies include: ... reduced number of digits on the pes (foot) to three main toes ...". I've just Googled for "dinosaur foot pes toes digits" and got several pages which contradict this, including "Ceratopsians usually have a blunt 4-toed pes and 5-digit manus" ( http://palaios.sepmonline.org/cgi/content/full/17/4/327). The same search revealed pages which suggested that theropods and ornithopods independently evolved 3-toed feet. Paul's "Predatory Dinosaurs of the World" says that staurikosaurs and herrerasaurs were 4-toed (1st page of ch 3). The prosauropod Anchisaurus appears to have had 5 fingers and 5 toes ( http://www.palaeos.com/Vertebrates/Units/330Sauropodomorpha/330.100.html#Anchisaurus)
I've even found (via Google for "dinosaur foot pes toes digits") pages that suggest that the perforate acetabulum (the holy of holies - groan!) was not a dino synapomorphy but the product of convergent evolution - e.g. http://www.palaeos.com/Vertebrates/Units/340Theropoda/340.100.html#Herrerasauridae, http://www.palaeos.com/Vertebrates/Units/330Sauropodomorpha/330.100.html (comments on Saturnalia - a good name for something that throws doubt on a central dogma).
The only list of synapomorphies I can find that does not rely on perforated acetabulum is http://dml.cmnh.org/2000May/msg00268.html - can anyone do better?
Looks like basal dino cladistics is in turmoil and this section will need regular checking against new discoveries.
Philcha 18:00, 5 October 2006 (UTC)
I'm writing here rather than fixing them because I'm not sure what they're trying to say, so could only remove.
Ingrid 17:03, 5 October 2006 (UTC)
Should there not be a short sentence explaining that birds are archosaurs and are therefore considered to be modern dinosaurs? For those people who don't already know this fact it would certainly avoid some confusion...-- Greebo cat 16:19, 23 October 2006 (UTC)
The first sentence says that religious views on dinosaurs don't agree with scientific views (using clumsy and vague weasel language, too), and the second says "see main article". Both are entirely redundant. If nothing substantial can be written in this section, I suggest just moving the link to the "See also" section. Fredrik Johansson 06:32, 7 October 2006 (UTC)
I'm not complaining about the section's existence. What I'm saying is that the two quoted sentences are poorly worded and redundant. Let's break it down:
In this case, no text is better than poor text. If someone can expand the section with non-vacuum language, that is of course better, but then do it. Fredrik Johansson 12:21, 12 October 2006 (UTC)
Why there is no mention of the "Jesus horse" phrase? It is a matter of fact that America has powerful sectarian groups that want to demote dinos to fit their seventh day flat earth agenda. The article should have a section explaining religio-political controversy about dinos and mention the Jesus horse. It is unacceptable to censor wikipedia articles just to hide american stupidity! 195.70.48.242 08:07, 16 October 2006 (UTC)
Dinosaurs have become a part of world culture and remain consistently popular, especially among young boys. This was changed from children to young boys. My problem is that there are many young girls that enjoy learning about dinosaurs and i fail to see the reason for the change. If any evidence can be provided that this edit was justified then by all means, change it back but as it is-i've left it at children. Greebo cat 01:02, 5 November 2006 (UTC)
Especially does not mean only.-- Emcee2k 05:13, 27 November 2006 (UTC)
This should be almost entirely removed, as there's a more complete page about the Cretaceous-Tertiary extinction event:
Philcha 00:28, 17 November 2006 (UTC)
The "dinosaurs" page should try to explain why the late Maastrichtian fossils were all pretty large - the smallest appear to have been Troodon and pachycephalosaurus. This is relevant to the extinction mystery - no purely land animals bigger than cat survived. If there had been small predatory dinosaurs in the late Maastrichtian, I'd have expected some of them to have survived by eating invertebrates and small mammals. Philcha 00:28, 17 November 2006 (UTC)
The "warm-bloodedness section should be almost entirely removed, as there's a more complete page about the Warm-bloodedness of dinosaurs. Philcha 00:42, 17 November 2006 (UTC)
I believe there is a large amount of evidence pointing to dinosaurs and man coexisting. I think this information should be included in the Wikipedia article:
- Trained scientists reported seeing a dinosaur. [1]
- 1,000 people had seen a dinosaur-like monster in two sightings around Sayram Lake in Xinjiang accrording to the Chinese publication, China Today (see: Lai Kuan and Jian Qun, ‘Dinosaurs: Alive and Well and Living in Northwest China?’, China Today, Vol. XLII No. 2, February 1993, p. 59.) [2]
- An expedition which included, Charles W. Gilmore, Curator of Vertebrate Paleontology with the United States National Museum, examined an ancient pictograph that pointed to dinosaurs and man existing [3] [4]
- The World Book Encyclopedia states that: "The dragons of legend are strangely like actual creatures that have lived in the past. They are much like the great reptiles [dinosaurs] which inhabited the earth long before man is supposed to have appeared on earth. Dragons were generally evil and destructive. Every country had them in its mythology." [5]
- The Nile Mosaic of Palestrina, a second century piece of art, appears to be a piece of artwork that shows a dinosaur and man coexisting. [6]
- On May 13, 1572 a dinosaur may have been killed by a peasant farmer in Italy (pg 41 "The Great Dinosaur Mystery" by Paul Taylor ISBN 0-89636-264-7) [7]
- It has been stated that dinosaurs are in the Bible. [8] [9] [10]
- There is other evidence that dinosaurs and man coexisted. 136.183.154.15 02:29, 29 November 2006 (UTC)
I believe that at this point your questions have been given a satisfactory answer; indeed, they have been given all the answer they deserve. Since you will doubtless not ever be persuaded by reason, there is little point in continuing the discussion. I will put this as simply as I can, in order to avoid any possible confusion:
What you have proposed is utter nonsense. It will not be included in the article. Doc Tropics 04:06, 29 November 2006 (UTC)
Hi Ken! You aren't supposed to edit when you are blocked. Guettarda 05:38, 29 November 2006 (UTC)
Oh, you'll never believe this. Here's his Illustrated London News cite:
"Very Like a Whale"- A discovery of great scientific importance has just been made at Culmont (Haute Marne). Some men employed in cutting a tunnel which is to unite the St. Dizier and Nancy railways, had just thrown down an enourmous block of stone by means of gunpowder and were in the act of breaking it to pieces, when from a cavity within it they suddenly saw emerge a living being of monstrous form. This creature, which belongs to a class of animals hitherto considered extinct, has a very long neck, and a mouth filled with sharp teeth. It stands on four long legs, which are united together by two membranes, doubtless intended to support the animal in the air, and are and are armed with four claws terminated by long and crooked talons. Its membranous wings, when spread out, measure from tip to tip 3 metres 2 centimetres (nearly 10 feet 7 inches). Its colour is a livid black; its skin is naked, thick, and oily,; its intestines only contained a colourless liquid like clear water. On reaching the light this monster gave some signs of life, by shaking its wings, but soon after expired, uttering a hoarse cry. This strange creature, to which may be given the name of living fossil, was brought to Gray, where a naturalist, well versed in study of palaeontology, immediately recognised it as belonging to the genus Pterodactylus anas, many fossil remains of which have been found among the strata which geologists have designated by the name of lias. The rock in which this monster was discovered belongs precisely to that formation the deposit of which is so old that geologists date it more than a million of years back. The cavity in which the animal was lodged forms an exact hollow mould of its body, which indicates it was completely enveloped with the sedimentry deposit -Presse Grayloise
...That last sentence speaks for itself, no? Are we realliy supposed to believe that it was entombe ofr millions of years, but CAME BACK TO LIFE ON EXCAVATION?!!?!? BWAHAHAHA! - Adam Cuerden, currently logged off.
Weel, this is the 1856 Reign of Fire (the modern one is a remake, except this one, like the original Amnityville Horror is claimed to be true. Where do they getting this stuff, then? Charles Fort? Adam Cuerden talk 16:33, 29 November 2006 (UTC)
Ha ha! Creationists are doomed if they keep in relying on stories like this. Here's an actual explanation for the hoax: [13]. In the original version, the pterodactyl crumbled to dust conveniently leaving no evidence. Note that there is no such species as Pterodactylus anas and anas is the latin for duck, which translates to 'canard' in french (in english this means 'an unfounded, false, or fabricated report or story') ArthurWeasley 18:44, 29 November 2006 (UTC)
Isn't it a bit weird that meat-eating dinosars were descendants to birds, when they belonged to the order Saurischia? Perhaps they evolved a bird-hip when they evolved into birds? It's always disturbed me. Were dinosaurs like Archaeopteryx and Microraptor bird-hipped or lizard-hipped?! And how the fuck could anyone write that dinosaurs and humans coexisted?! —The preceding unsigned comment was added by 83.181.53.36 ( talk) 15:12, 6 December 2006 (UTC).
We seem to have lost "Image:Eoraptor.jpg" in the "Evolution of dinosaurs" section; does anyone know what happened? Should this link be removed/replaced? If the image was deleted for some reason, a replacement would be useful, but finding and licensing images is not one of my strong points. Perhaps someone could help with this? : ) Doc Tropics 17:43, 9 December 2006 (UTC)
Every time I read something that has to do with Early Dinosaurs, people talk about Eoraptor, Herrerasaurus and even Coelophysis, but I've never heard anyone talk about Staurikosaurus. WHY?!. It lived far earlier than any of those other creatures, and I've only ever heard it stated as the earliest dinosaur in websites that deal specifically with it, not in websites that talk about the earliest dinosaurs. In-fact, where most sources state that Dinosaurs evolved in the Late Triassic, it is stated with staurikosaurus that it was a Middle Triassic dinosaur!. So why is there never any mention of it, yet there is mention of the others?!. And for the record, there have been recent discoveries about even earlier dinosaurs (prosauropods from Madagascar). And, though there is no discovered evidence for it and I am not a proffessional, I suspect that Dinosaurs actually evolved sometime in the Early Triassic. - 12:38, 16 December 2006 (UTC)
If nobody objects or offers alternative suggestions within a week, I'll edit the "dinosaur" page to:
This currently duplicates too much of the K-T extinction article, gives too much space to the Alvarez impact theory and omits the other really strong contender, the Deccan Traps flood basalt event.
I suggest this section should:
This section is too long and duplicates too much of the article "Warm-bloodedness of dinosaurs".
It also states, mistakenly AFAIK, that 19th century scientists regard dinos as cold-blooded. I'm not sure what Owen's view was, but T.H. Huxley was impressed by their similarities to birds (implies active and therefore "warm-blooded"), and Charles R. Wilson's famous painting "Fighting Laelaps" (now called Dryptosaurus) shows 2 dinos leaping at each other like fighting cocks. Philcha 00:37, 23 December 2006 (UTC)
The section also misses the real issue: were dinos sluggish or active? If they were sluggish, how did they remain the dominant terrestrial vertebrates for 150MY? As Bakker ("Dinosaur Heresies") points out, mammal's high activity levels make them the dominant terrestrial vertebrates except in very special environments (small islands, e.g. Komodo, where prey biomass is insufficient to support large mammalian predators; deserts, where diapsids' superior water conservation is critical). Philcha 13:47, 9 January 2007 (UTC)
I edited this section because it was kind of ugly previously; it was reworded, and I don't really have a problem with it. However, I do question the use of written scriptures rather than mythology; while Christian, Jewish, and Muslim fundamentalists are the most common and prominent religious folk who oppose it, they aren't the only ones, and mythology is more inclusive as not all religious folk who oppose the standard interpretation of dinosaur fossils have written scriptures, necessarily. I don't really have any sources on hand to dispute it though, so if anyone does one way or the other, it'd be nice; I'm not sure if its important or not. Thoughts/comments/opinions/sources? Titanium Dragon 10:18, 25 December 2006 (UTC)
The Religious Perspectives on Dinosaurs sub-article linked to by this article is currently up for deletion, with lots of support for that position.
Just thought I would mention that here. I personally support keeping the sub-article, since religious views on dinosaurs are significant minority positions that should be given coverage on Wikipedia... even if we don't personally agree with them. Various religious groups do have specific views about dinosaurs in particular, whereas this is not the case for, say, ancient organisms such as trilobites that haven't captured the popular imagination. These views shouldn't be completely "disappeared" on Wikipedia IMO, even though they're specious, anti-intellectual, &c.
This issue has been discussed nearly to death here over the past couple of years, so I won't belabor the pros and cons again. Suffice it to say that placing information about religious perspectives on dinosaurs in a sub-article has seemed to work pretty well since we implemented the change back in January '06. Killdevil 06:09, 26 December 2006 (UTC)
According to this, Dinosaur is one of the most popular pages on Wikipedia, receiving over 4,000 visitors a day, which works out to over 1.5 million views per year. As near as I can tell, the only animal-related articles which rank higher are Cat, Animal, List of dog breeds, and Snake. Firsfron of Ronchester 10:05, 29 December 2006 (UTC)
I request that we discuss image swapping here before it's done on a massive scale in the live article. This is a featured article, after all, and while there's certainly room for improvement in terms of imagery, I'm not sure that the outcome of the past couple of days' editing was an overall improvement.
Perhaps you could post the images you want to swap out in a gallery here first?
I'm also not sure that replacing several paragraphs of decent text with hard-to-read bullet-point lists was a good idea... let's talk about that stuff here too, maybe? Killdevil 03:35, 11 January 2007 (UTC)
Regarding the image swapping: Mgig replaced several images with other images.
Personally, I have no problem with the replacements, except possibly that the Stegosaurus swap replaced an image with the correct thagomizer with an outdated thagomizer. Any other comments? I also noted browsing the history of the article that a "citation needed" template was placed, and someone added the citation. That edit needs to be reinstated. Firsfron of Ronchester 18:39, 16 January 2007 (UTC)
Hi; we've got a link, www.nhm.ac.uk/nature-online/life/dinosaurs-other-extinct-creatures/index.html, which can get you there.
I have recently checked on the article, only to find that most of the good pictures have been replaced with a multitude of pictures, some of which aren't as good. Currently, there are too many pictures on the article. Some of the T. rex pictures have been removed, & let's face it, he's one of the most popular therefore should get at least 1 more picture than he currently has. None of the "periods" or full stops were in place on the image captions & for a FA quality article, this should have picked up on. I agree with people above, I'd prefer a few less artist's depictions & a couple more photos. But overall, the number needs to be decreased as it isn't looking very FA class right now. Articles aren't picture galleries, but encyclopedic pages. Thoguhts on what to do as I'd hate to see this article reviewed... Spawn Man 22:31, 31 January 2007 (UTC)
Im doing a research on dinosaurs and was wondering if I could interview someone via email. I just need a few of your words to cite in my report.
1. The "evolution" section could be expanded. It is not very informative now. It is good to know what types of dinosaurs evolved and became dominant during each period (and perhaps - some existing speculations as to why they evolved and became dominant; e.g., why were the carnivores so predominantly bipedal, and the herbivores quadrupedal, why did the sauropods evolve such long necks, and why did they decline somewhat and yield to different groups, why did so many attend such enormous size, etc.), how did the total "pool" of dinosaur species change over time? Also, while cladistics is all very nice, the good old "tree" pictures of evolution are intuitively easier to grasp. I had better not try to do something like that myself, because my most recent dinosaur book is from the early nineties and I am likely to get it wrong (not to mention that it reqires some work :))
2. A section about dinosaur intelligence might be useful. I believe it has been the subject of controversy, somewhat like (and in connection with) warm-bloodedness, and all those disturbing facts about astoundingly small brains deserve mention.
Both of these issues are touched upon here and there in articles about particular species and groups, but you don't get a global picture there. -- 91.148.159.4 19:07, 16 February 2007 (UTC)
Only one dinosaur species has been identified as having a four chambered heart, and the idea is scientifically dubious, i know of at least 2 papers the openly criticise the findings of the paper. shall i add this, and references for both papers, or simply remove the comments? Mikey - "so emo, it hurts"© 15:51, 18 February 2007 (UTC)
This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 | ← | Archive 4 | Archive 5 | Archive 6 | Archive 7 | Archive 8 | → | Archive 10 |
To preserve the intelligibility of conversation here I have once again moved older discussions on this page to the archive (Archive 5 linked just above). Killdevil 18:30, 19 August 2006 (UTC)
Killdevil -> I somewhat shrunk this section because I find it is becoming rather long and messy: it looks like a list of unrelated news events which have been independently added each time a fresh research news was available. In my opinion this section should be rewritten in a more concise way and the detailed information should be found on separate pages such as Feathered dinosaurs or Dinosaur-bird connection. (Currently, whole paragraphs are duplicated with some inconsistencies). So in short: I did not delete information but moved it to more specialized pages. -- Ollivier 17:29, 1 September 2006 (UTC)
Some bits of text I have some problems with:
I checked the refs and altered the numbers and ranks accordingly because in the state above it doesn't make much sense regarding my knowledge of the subject.
I was under the impression that the skeletons accumulated over time. IIRC there were at least two levels of skeletons in the Bernissart coal mine. After a bit of searching I found this pertinent article:
The meat of it is in French so I'll have to work a bit disentangling the relevant bits of text. I can tell one thing for sure: It wasn't a ravine where the Iguanodon fell but one of the many sinkholes existing in the area at the time. Come to think of it, it stands to reason it should be so, as usually a ravine has a way out: downstream.
I'm pretty sure Lagosuchus isn't a dinosaur, though a dinosauriform, and not even a particularly well defined genus. Barring the likely chance "dinosaur" is being used a shorthand for anything ornithodiran more closely related to Dinosauria I'd propose Marasuchus for the place and that it'd be stated that it is a close relative of dinosaurs.
Oh and let it be know that the edit made on the article by User:193.136.225.26 is mine and that it is related with this post. I like to preview a lot and I do have to go to the men's room on occasion ;P Dracontes 10:01, 18 September 2006 (UTC)
It also fails to account for how the animals in question, sauropods, would regulate their temperature before they got to that size in the first place, IMHO, as they did start quite small. Dracontes 15:37, 2 March 2007 (UTC)
Both of these groups are theropods. Both are classed as their own distinct lineages. Yet both contained feathered representatives. And it is almost (though not entirely) certain that feathers evolved only once. What gives?. Do the feathered creatures fall under one clade or the other?. - 03:31, 24 September 2006 (UTC)
I'm still waiting for an answer. I expected this page to have higher web traffic. Anybody reading this, please leave at-least a comment. - 01:33, 29 September 2006 (UTC)
Correct me if I am wrong, but last I heard Alvarezsaurs were classed as ceratosaurs. - 15:59, 29 September 2006 (UTC)
Of course I could be wrong; that was a long time ago, on an old book. I would have to check the Ceratosaur clade once more. - 16:04, 29 September 2006 (UTC)
As far as I know, alvarezsaurs are not considered ceratosaurs anymore. Either they appear as birds in cladistic analyses, or as more basal theropods, but always within Coelurosauria (sometimes close to ornithomimids). -- Ollivier 21:06, 30 September 2006 (UTC)
OK. I can't remember any other potentially feathered ceratosaurs. I guess that answers my question. - 21:52, 30 September 2006 (UTC)
Re erect limbs (under "Other shared anatomical features"), reptiles with sprawling limbs can move about as fast as similar-sized mammals with erect limbs. The main advantage of erect limbs is that they eliminate Carrier's Constraint (new article needed), so that the animal can breathe efficiently while moving. This gives animals with erect limbs greater stamina than animals with sprawling limbs.
Re dino metabolism, a lot of the bone structure and soft tissue evidence is ambiguous and / or disputed. For example some of the bone structre features are found in a few cold-bloded reptiles and not in some mammals. And the specialist paleontology sites are full of debates about whether some fossilised features represent e.g. 4-chambered hearts or just artefacts of the fossilisation process.
In my opinion the best arguments for "warm-blooded" dinos (i.e. metabolic rate comparable to that of mammals of similar size) are:
Sprawling limbs are efficient for a creature that spens most of its time flopped on its belly and only moves for a few seconds at a time, because they minimise the costs of getting up and lying down but make the animal subject to Carrier's Constraint. Erect limbs are the opposite - they avoid Carrier's Constraint, but increase the costs of of getting up and lying down (in mammals, which mostly have very flexible backbones, they also pump the lungs when running; but most dinos had short rigid backbones, like birds, so would not have enjoyed this additional advantage) - so erect limbs are a disadvantage for a sluggish animal and an advantage for an active animal. In addition, dinos were fundamentally bipeds, and bipedalism makes getting up even more laborious as it removes the option to get up one end at a time (as cows do). So I think erect limbs + bipedalism indicates an active lifestyle and high metabolic rate.
Dino fossils have been found in areas which were within the Antarctic Circle during the Mesozoic and show signs of having had regular frosts. Cold-blooded reptiles can only survive frost by burrowing and hibernating, but the fossil dinos were fairly large by modern standards and we've found no evidence of burrowing dinos. So it appears dinos could generate adequate heat in these conditions, which indicates a high metabolic rate.
Studies of T Rex' lifecycle (e.g. http://www.bioedonline.org/news/news.cfm?art=1067, http://www-geology.ucdavis.edu/~cowen/HistoryofLife/CH12.html, http://www.naturalhistorymag.com/0505/0505_feature.html, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15347508&query_hl=1) indicate that it grew in 3 stages: (a) slow growth up to 1 ton weight at about age 10; (b) rapid growth to 5-7 tons at about age 16, an average increase of a ton per year(!); (c) negligible growth after that. Stage (b) indicates a fast metabolism - compare with crocs, which take 15 years to reach sexual maturity and a lot longer to reach full size. I've seen no growth timescales for sauropods, but I've seen many arguments that they would have had to grow fast (at least at some stage), as their eggs range in size between a large melon and a basketball and most sauropods reached 30 to over 100 tons at maturity depending on species.
I've also just seen a paper ( http://palaeo-electronica.org/1999_2/gigan/discus.htm) which argues that oxygen isotope ratios in the bones of adult T Rex and Giganotosaurus indicate a rapid metabolism but that this was achieved by inertial homeothermy (because distal bones show "cooler" isotope ratios). So it would be interesting to see whether there have been similar studies on smaller dinos (e.g. Velociraptor, ornithomimids). And of course inertial homeothermy would not have worked for juvenile dinos.
Wkipedia ought also to reference http://wiki.cotch.net/index.php?title=A_Reply_to_Ruben_on_Theropod_Physiology&printable=yes. This paper summarises and criticses Ruben's argument that dinos lacked respiratory conchae (aka nasal turbinates), which since its publication in 1996 has been one of the most-quoted reasons for believing that dinos were ectothermic.
Philcha 17:47, 5 October 2006 (UTC)
Just found http://www.physorg.com/news73665780.html, in which the researchers say that their lifecycle data on Albertosaurs does not suggest super-fast growth in the teenage years.
BTW I also wrote the last post ("Erect gait; metabolism"), but forgot to sign it.
Philcha 18:01, 5 October 2006 (UTC)
The article wrongly says "Dinosaur synapomorphies include: ... reduced number of digits on the pes (foot) to three main toes ...". I've just Googled for "dinosaur foot pes toes digits" and got several pages which contradict this, including "Ceratopsians usually have a blunt 4-toed pes and 5-digit manus" ( http://palaios.sepmonline.org/cgi/content/full/17/4/327). The same search revealed pages which suggested that theropods and ornithopods independently evolved 3-toed feet. Paul's "Predatory Dinosaurs of the World" says that staurikosaurs and herrerasaurs were 4-toed (1st page of ch 3). The prosauropod Anchisaurus appears to have had 5 fingers and 5 toes ( http://www.palaeos.com/Vertebrates/Units/330Sauropodomorpha/330.100.html#Anchisaurus)
I've even found (via Google for "dinosaur foot pes toes digits") pages that suggest that the perforate acetabulum (the holy of holies - groan!) was not a dino synapomorphy but the product of convergent evolution - e.g. http://www.palaeos.com/Vertebrates/Units/340Theropoda/340.100.html#Herrerasauridae, http://www.palaeos.com/Vertebrates/Units/330Sauropodomorpha/330.100.html (comments on Saturnalia - a good name for something that throws doubt on a central dogma).
The only list of synapomorphies I can find that does not rely on perforated acetabulum is http://dml.cmnh.org/2000May/msg00268.html - can anyone do better?
Looks like basal dino cladistics is in turmoil and this section will need regular checking against new discoveries.
Philcha 18:00, 5 October 2006 (UTC)
I'm writing here rather than fixing them because I'm not sure what they're trying to say, so could only remove.
Ingrid 17:03, 5 October 2006 (UTC)
Should there not be a short sentence explaining that birds are archosaurs and are therefore considered to be modern dinosaurs? For those people who don't already know this fact it would certainly avoid some confusion...-- Greebo cat 16:19, 23 October 2006 (UTC)
The first sentence says that religious views on dinosaurs don't agree with scientific views (using clumsy and vague weasel language, too), and the second says "see main article". Both are entirely redundant. If nothing substantial can be written in this section, I suggest just moving the link to the "See also" section. Fredrik Johansson 06:32, 7 October 2006 (UTC)
I'm not complaining about the section's existence. What I'm saying is that the two quoted sentences are poorly worded and redundant. Let's break it down:
In this case, no text is better than poor text. If someone can expand the section with non-vacuum language, that is of course better, but then do it. Fredrik Johansson 12:21, 12 October 2006 (UTC)
Why there is no mention of the "Jesus horse" phrase? It is a matter of fact that America has powerful sectarian groups that want to demote dinos to fit their seventh day flat earth agenda. The article should have a section explaining religio-political controversy about dinos and mention the Jesus horse. It is unacceptable to censor wikipedia articles just to hide american stupidity! 195.70.48.242 08:07, 16 October 2006 (UTC)
Dinosaurs have become a part of world culture and remain consistently popular, especially among young boys. This was changed from children to young boys. My problem is that there are many young girls that enjoy learning about dinosaurs and i fail to see the reason for the change. If any evidence can be provided that this edit was justified then by all means, change it back but as it is-i've left it at children. Greebo cat 01:02, 5 November 2006 (UTC)
Especially does not mean only.-- Emcee2k 05:13, 27 November 2006 (UTC)
This should be almost entirely removed, as there's a more complete page about the Cretaceous-Tertiary extinction event:
Philcha 00:28, 17 November 2006 (UTC)
The "dinosaurs" page should try to explain why the late Maastrichtian fossils were all pretty large - the smallest appear to have been Troodon and pachycephalosaurus. This is relevant to the extinction mystery - no purely land animals bigger than cat survived. If there had been small predatory dinosaurs in the late Maastrichtian, I'd have expected some of them to have survived by eating invertebrates and small mammals. Philcha 00:28, 17 November 2006 (UTC)
The "warm-bloodedness section should be almost entirely removed, as there's a more complete page about the Warm-bloodedness of dinosaurs. Philcha 00:42, 17 November 2006 (UTC)
I believe there is a large amount of evidence pointing to dinosaurs and man coexisting. I think this information should be included in the Wikipedia article:
- Trained scientists reported seeing a dinosaur. [1]
- 1,000 people had seen a dinosaur-like monster in two sightings around Sayram Lake in Xinjiang accrording to the Chinese publication, China Today (see: Lai Kuan and Jian Qun, ‘Dinosaurs: Alive and Well and Living in Northwest China?’, China Today, Vol. XLII No. 2, February 1993, p. 59.) [2]
- An expedition which included, Charles W. Gilmore, Curator of Vertebrate Paleontology with the United States National Museum, examined an ancient pictograph that pointed to dinosaurs and man existing [3] [4]
- The World Book Encyclopedia states that: "The dragons of legend are strangely like actual creatures that have lived in the past. They are much like the great reptiles [dinosaurs] which inhabited the earth long before man is supposed to have appeared on earth. Dragons were generally evil and destructive. Every country had them in its mythology." [5]
- The Nile Mosaic of Palestrina, a second century piece of art, appears to be a piece of artwork that shows a dinosaur and man coexisting. [6]
- On May 13, 1572 a dinosaur may have been killed by a peasant farmer in Italy (pg 41 "The Great Dinosaur Mystery" by Paul Taylor ISBN 0-89636-264-7) [7]
- It has been stated that dinosaurs are in the Bible. [8] [9] [10]
- There is other evidence that dinosaurs and man coexisted. 136.183.154.15 02:29, 29 November 2006 (UTC)
I believe that at this point your questions have been given a satisfactory answer; indeed, they have been given all the answer they deserve. Since you will doubtless not ever be persuaded by reason, there is little point in continuing the discussion. I will put this as simply as I can, in order to avoid any possible confusion:
What you have proposed is utter nonsense. It will not be included in the article. Doc Tropics 04:06, 29 November 2006 (UTC)
Hi Ken! You aren't supposed to edit when you are blocked. Guettarda 05:38, 29 November 2006 (UTC)
Oh, you'll never believe this. Here's his Illustrated London News cite:
"Very Like a Whale"- A discovery of great scientific importance has just been made at Culmont (Haute Marne). Some men employed in cutting a tunnel which is to unite the St. Dizier and Nancy railways, had just thrown down an enourmous block of stone by means of gunpowder and were in the act of breaking it to pieces, when from a cavity within it they suddenly saw emerge a living being of monstrous form. This creature, which belongs to a class of animals hitherto considered extinct, has a very long neck, and a mouth filled with sharp teeth. It stands on four long legs, which are united together by two membranes, doubtless intended to support the animal in the air, and are and are armed with four claws terminated by long and crooked talons. Its membranous wings, when spread out, measure from tip to tip 3 metres 2 centimetres (nearly 10 feet 7 inches). Its colour is a livid black; its skin is naked, thick, and oily,; its intestines only contained a colourless liquid like clear water. On reaching the light this monster gave some signs of life, by shaking its wings, but soon after expired, uttering a hoarse cry. This strange creature, to which may be given the name of living fossil, was brought to Gray, where a naturalist, well versed in study of palaeontology, immediately recognised it as belonging to the genus Pterodactylus anas, many fossil remains of which have been found among the strata which geologists have designated by the name of lias. The rock in which this monster was discovered belongs precisely to that formation the deposit of which is so old that geologists date it more than a million of years back. The cavity in which the animal was lodged forms an exact hollow mould of its body, which indicates it was completely enveloped with the sedimentry deposit -Presse Grayloise
...That last sentence speaks for itself, no? Are we realliy supposed to believe that it was entombe ofr millions of years, but CAME BACK TO LIFE ON EXCAVATION?!!?!? BWAHAHAHA! - Adam Cuerden, currently logged off.
Weel, this is the 1856 Reign of Fire (the modern one is a remake, except this one, like the original Amnityville Horror is claimed to be true. Where do they getting this stuff, then? Charles Fort? Adam Cuerden talk 16:33, 29 November 2006 (UTC)
Ha ha! Creationists are doomed if they keep in relying on stories like this. Here's an actual explanation for the hoax: [13]. In the original version, the pterodactyl crumbled to dust conveniently leaving no evidence. Note that there is no such species as Pterodactylus anas and anas is the latin for duck, which translates to 'canard' in french (in english this means 'an unfounded, false, or fabricated report or story') ArthurWeasley 18:44, 29 November 2006 (UTC)
Isn't it a bit weird that meat-eating dinosars were descendants to birds, when they belonged to the order Saurischia? Perhaps they evolved a bird-hip when they evolved into birds? It's always disturbed me. Were dinosaurs like Archaeopteryx and Microraptor bird-hipped or lizard-hipped?! And how the fuck could anyone write that dinosaurs and humans coexisted?! —The preceding unsigned comment was added by 83.181.53.36 ( talk) 15:12, 6 December 2006 (UTC).
We seem to have lost "Image:Eoraptor.jpg" in the "Evolution of dinosaurs" section; does anyone know what happened? Should this link be removed/replaced? If the image was deleted for some reason, a replacement would be useful, but finding and licensing images is not one of my strong points. Perhaps someone could help with this? : ) Doc Tropics 17:43, 9 December 2006 (UTC)
Every time I read something that has to do with Early Dinosaurs, people talk about Eoraptor, Herrerasaurus and even Coelophysis, but I've never heard anyone talk about Staurikosaurus. WHY?!. It lived far earlier than any of those other creatures, and I've only ever heard it stated as the earliest dinosaur in websites that deal specifically with it, not in websites that talk about the earliest dinosaurs. In-fact, where most sources state that Dinosaurs evolved in the Late Triassic, it is stated with staurikosaurus that it was a Middle Triassic dinosaur!. So why is there never any mention of it, yet there is mention of the others?!. And for the record, there have been recent discoveries about even earlier dinosaurs (prosauropods from Madagascar). And, though there is no discovered evidence for it and I am not a proffessional, I suspect that Dinosaurs actually evolved sometime in the Early Triassic. - 12:38, 16 December 2006 (UTC)
If nobody objects or offers alternative suggestions within a week, I'll edit the "dinosaur" page to:
This currently duplicates too much of the K-T extinction article, gives too much space to the Alvarez impact theory and omits the other really strong contender, the Deccan Traps flood basalt event.
I suggest this section should:
This section is too long and duplicates too much of the article "Warm-bloodedness of dinosaurs".
It also states, mistakenly AFAIK, that 19th century scientists regard dinos as cold-blooded. I'm not sure what Owen's view was, but T.H. Huxley was impressed by their similarities to birds (implies active and therefore "warm-blooded"), and Charles R. Wilson's famous painting "Fighting Laelaps" (now called Dryptosaurus) shows 2 dinos leaping at each other like fighting cocks. Philcha 00:37, 23 December 2006 (UTC)
The section also misses the real issue: were dinos sluggish or active? If they were sluggish, how did they remain the dominant terrestrial vertebrates for 150MY? As Bakker ("Dinosaur Heresies") points out, mammal's high activity levels make them the dominant terrestrial vertebrates except in very special environments (small islands, e.g. Komodo, where prey biomass is insufficient to support large mammalian predators; deserts, where diapsids' superior water conservation is critical). Philcha 13:47, 9 January 2007 (UTC)
I edited this section because it was kind of ugly previously; it was reworded, and I don't really have a problem with it. However, I do question the use of written scriptures rather than mythology; while Christian, Jewish, and Muslim fundamentalists are the most common and prominent religious folk who oppose it, they aren't the only ones, and mythology is more inclusive as not all religious folk who oppose the standard interpretation of dinosaur fossils have written scriptures, necessarily. I don't really have any sources on hand to dispute it though, so if anyone does one way or the other, it'd be nice; I'm not sure if its important or not. Thoughts/comments/opinions/sources? Titanium Dragon 10:18, 25 December 2006 (UTC)
The Religious Perspectives on Dinosaurs sub-article linked to by this article is currently up for deletion, with lots of support for that position.
Just thought I would mention that here. I personally support keeping the sub-article, since religious views on dinosaurs are significant minority positions that should be given coverage on Wikipedia... even if we don't personally agree with them. Various religious groups do have specific views about dinosaurs in particular, whereas this is not the case for, say, ancient organisms such as trilobites that haven't captured the popular imagination. These views shouldn't be completely "disappeared" on Wikipedia IMO, even though they're specious, anti-intellectual, &c.
This issue has been discussed nearly to death here over the past couple of years, so I won't belabor the pros and cons again. Suffice it to say that placing information about religious perspectives on dinosaurs in a sub-article has seemed to work pretty well since we implemented the change back in January '06. Killdevil 06:09, 26 December 2006 (UTC)
According to this, Dinosaur is one of the most popular pages on Wikipedia, receiving over 4,000 visitors a day, which works out to over 1.5 million views per year. As near as I can tell, the only animal-related articles which rank higher are Cat, Animal, List of dog breeds, and Snake. Firsfron of Ronchester 10:05, 29 December 2006 (UTC)
I request that we discuss image swapping here before it's done on a massive scale in the live article. This is a featured article, after all, and while there's certainly room for improvement in terms of imagery, I'm not sure that the outcome of the past couple of days' editing was an overall improvement.
Perhaps you could post the images you want to swap out in a gallery here first?
I'm also not sure that replacing several paragraphs of decent text with hard-to-read bullet-point lists was a good idea... let's talk about that stuff here too, maybe? Killdevil 03:35, 11 January 2007 (UTC)
Regarding the image swapping: Mgig replaced several images with other images.
Personally, I have no problem with the replacements, except possibly that the Stegosaurus swap replaced an image with the correct thagomizer with an outdated thagomizer. Any other comments? I also noted browsing the history of the article that a "citation needed" template was placed, and someone added the citation. That edit needs to be reinstated. Firsfron of Ronchester 18:39, 16 January 2007 (UTC)
Hi; we've got a link, www.nhm.ac.uk/nature-online/life/dinosaurs-other-extinct-creatures/index.html, which can get you there.
I have recently checked on the article, only to find that most of the good pictures have been replaced with a multitude of pictures, some of which aren't as good. Currently, there are too many pictures on the article. Some of the T. rex pictures have been removed, & let's face it, he's one of the most popular therefore should get at least 1 more picture than he currently has. None of the "periods" or full stops were in place on the image captions & for a FA quality article, this should have picked up on. I agree with people above, I'd prefer a few less artist's depictions & a couple more photos. But overall, the number needs to be decreased as it isn't looking very FA class right now. Articles aren't picture galleries, but encyclopedic pages. Thoguhts on what to do as I'd hate to see this article reviewed... Spawn Man 22:31, 31 January 2007 (UTC)
Im doing a research on dinosaurs and was wondering if I could interview someone via email. I just need a few of your words to cite in my report.
1. The "evolution" section could be expanded. It is not very informative now. It is good to know what types of dinosaurs evolved and became dominant during each period (and perhaps - some existing speculations as to why they evolved and became dominant; e.g., why were the carnivores so predominantly bipedal, and the herbivores quadrupedal, why did the sauropods evolve such long necks, and why did they decline somewhat and yield to different groups, why did so many attend such enormous size, etc.), how did the total "pool" of dinosaur species change over time? Also, while cladistics is all very nice, the good old "tree" pictures of evolution are intuitively easier to grasp. I had better not try to do something like that myself, because my most recent dinosaur book is from the early nineties and I am likely to get it wrong (not to mention that it reqires some work :))
2. A section about dinosaur intelligence might be useful. I believe it has been the subject of controversy, somewhat like (and in connection with) warm-bloodedness, and all those disturbing facts about astoundingly small brains deserve mention.
Both of these issues are touched upon here and there in articles about particular species and groups, but you don't get a global picture there. -- 91.148.159.4 19:07, 16 February 2007 (UTC)
Only one dinosaur species has been identified as having a four chambered heart, and the idea is scientifically dubious, i know of at least 2 papers the openly criticise the findings of the paper. shall i add this, and references for both papers, or simply remove the comments? Mikey - "so emo, it hurts"© 15:51, 18 February 2007 (UTC)