1. Welcome to Religious Forums, a friendly forum to discuss all religions in a friendly surrounding.

    Your voice is missing! You will need to register to get access to the following site features:
    • Reply to discussions and create your own threads.
    • Our modern chat room. No add-ons or extensions required, just login and start chatting!
    • Access to private conversations with other members.

    We hope to see you as a part of our community soon!

Featured Paleontology: the dinosaur-bird connection

Discussion in 'Evolution Vs. Creationism' started by gnostic, Jan 22, 2022.

  1. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    First, I'll give a little historical background on the paleontology - the study of fossils , and the classification of those fossils. Then I'll focus on the fossils of dinosaurs and their connections with reptiles and with birds.

    While some fossils were uncovered and known since ancient times, these people didn't really know what they were seeing, especially when there are many animals that have been extinct long before their times. Of course, some fossils were recognizable, because of comparison of fossil samples with living samples.

    Apart from recognizing that life were some how petrified, they don't know when these animals became fossils, nor when they have died. So I don't know of any historical records where people actually "study" these fossils.

    Actual scientific studies of fossils didn't start until the 19th century, especially when it first identified dinosaur fossils. The term dinosaur was coined by English biologist Richard Owen, which meant “terrible lizard” in the mid-19th century.

    Today, while we understand that dinosaurs evolved from earlier primitive reptiles - especially from the sa, dinosaurs are not “lizards”, because when we view the modern lizards they have sprawling limbs, legs that protrude outward from the sides of their bodies, hence lizards have sprawling gaits when they moved about.

    The study of dinosaurs’ shoulders, hips and limbs actually have more erect limbs mostly directly below their bodies. Some of these dinosaurs have bird-like hip, which also differed from lizards.

    And though dinosaurs have evolved from earlier reptiles, they aren’t cold-blooded reptiles, like lizards, crocodiles and snakes.

    The first person to proposed that birds evolved from dinosaurs, was another English biologist, Thomas Henry Huxley. Of course, for decades after Huxley most disagree with this concept (eg Richard Owen), because some still held on to beliefs that dinosaurs were ancestors of the modern cold-blooded reptiles, like the lizards and crocodiles, but all the evidence have shown this concept to be false, that Huxley was correct about the dinosaur-bird connection.

    Dinosaurs have more in common with birds than they do with crocodiles.

    The points being that before there were dinosaurs (hence pre-Mesozoic era, primitive reptiles were more varied than previously thought, so some were cold-blooded reptiles, while other reptiles were warm-blooded. Some have sprawling limbs (like lizards and crocodiles), while other reptiles didn’t have such limb structure.

    Do you agree or disagree?
     
    • Like Like x 3
    • Informative Informative x 1
  2. Audie

    Audie Veteran Member

    Joined:
    Feb 18, 2018
    Messages:
    22,404
    Ratings:
    +11,612
    Religion:
    None
    Sort of
     
  3. ChristineM

    ChristineM "Be strong" I whispered to my coffee.
    Premium Member

    Joined:
    Mar 3, 2017
    Messages:
    44,667
    Ratings:
    +41,116
    Religion:
    None
    Agree to an extent.
    There is plenty of evidence that some dinosaurs from the Cretaceous period had avian like crops.
    There is evidence of feathered dinosaurs.

    However there is also evidence that crocodiles share a common ancestor with dinosaurs.

    The thing is dinosaurs were not all a related group of species, they were many and varied which helped to give rise to much of the diversity of life today
     
    • Like Like x 1
    • Informative Informative x 1
  4. Audie

    Audie Veteran Member

    Joined:
    Feb 18, 2018
    Messages:
    22,404
    Ratings:
    +11,612
    Religion:
    None
    As in sort- of, but with more details. :D

    Feathered dinosaurs have well preserved,
    more like proof than evidence.

    As you noted, the categories of. " bird ",
    "reptile ", dont match well between todays
    forms.

    Upon seeing a warm blooded, feathered
    creature that is labelled " reptile " coz its
    a dinosaur would confabulate the time traveller.
     
    • Like Like x 2
  5. exchemist

    exchemist Veteran Member

    Joined:
    Apr 24, 2018
    Messages:
    15,429
    Ratings:
    +15,651
    Religion:
    RC (culturally at least)
    You appear to be reciting the settled consensus of palaeontology. I can't see anything to disagree with.

    Except that I wasn't aware it was finally sure that dinosaurs were warm-blooded (endotherms), though I knew the consensus was moving in that direction.
     
    • Like Like x 1
  6. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    I was following the taxonomic that grouped them all together and got spun around - which made me rather confused, because different periods, paleontologists have different takes, since 1988.

    So if I understand the lines correctly, the crocodiles and birds have shared or common ancestor with the archosaurs or with the archosaur clade in the Triassic period; the birds connecting to the archosaurs, via the dinosaurs.

    So, the clade of Archosauria being the “crown clade”, then I should follow the most recent tree or recent phylogeny - the Stirling Nesbitt’s tree (2011).
     
    • Informative Informative x 1
  7. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    Yes, you are right, they do varied, but from what understand the archosaurs are what connected them all.

    The archosaurs also varied physically with their stances and movements, hence the locomotive of their hips and limbs. Some archosaurs have the locomotion where legs were “erect” (hence like some of dinosaurs) and “erect-pillar” (again, like some other dinosaurs), and some have “sprawling” limbs (eg crocodiles).
     
    • Informative Informative x 1
  8. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    I am no biological expert...as I said in past topics, I just read a lot.

    So if I am reading what I have read correctly, it is all matters of biology, and in this case, the more erect they stand and the way they move, plus the weight distribution of dinosaurs would suggest they require higher energy, and higher metabolism.

    So higher metabolism in dinosaurs, wouldn’t that suggest higher temperature, hence them being warm-blooded?

    Edit:

    I am not “telling you”, I am “asking you”, because I think you know more about biology than I do. I think you’d know more about the bodies work.
     
    #8 gnostic, Jan 22, 2022
    Last edited: Jan 22, 2022
  9. exchemist

    exchemist Veteran Member

    Joined:
    Apr 24, 2018
    Messages:
    15,429
    Ratings:
    +15,651
    Religion:
    RC (culturally at least)
    I seem to recall an issue to do with bone structure, as preserved in fossils, that sheds light on whether they were warm or cold blooded, but it was many years ago and I have not followed the topic.
     
  10. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    Feathers...of course. * smack forehead *

    That’s one of the things I forgot to mention in the OP. :oops:
     
    • Like Like x 1
    • Funny Funny x 1
  11. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    Well, if you do follow up, let us know...

    ...because I’d like to know myself.
     
  12. exchemist

    exchemist Veteran Member

    Joined:
    Apr 24, 2018
    Messages:
    15,429
    Ratings:
    +15,651
    Religion:
    RC (culturally at least)
    The Wiki article has something on this: Physiology of dinosaurs - Wikipedia
    Haversian canals is what I was thinking of - though I did not know the term.
     
    • Useful Useful x 1
  13. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    Thanks for link.

    I didn’t know about the Haversian canals myself.

    From what I can see in the article, bone structure are not conclusive enough to determine if the dinosaurs were warm-blooded.
     
  14. gnostic

    gnostic The Lost One

    Joined:
    Jan 12, 2006
    Messages:
    18,510
    Ratings:
    +5,837
    Religion:
    Pi π
    @ChristineM

    From what I was able to grasp, the Archosauria can be divided in several broad groups:
    1. of which birds (including dinosaurs) went one way, which I have just found out from link that exchemist provided me, led to another link, so this group of archosaurs was called Avemetatarsalia clade,
    2. while the other group leads to the crocodilian clade of the archosaurs.
    I didn’t know of this clade - Avemetatarsalia.

    So the Avemetatarsalia were archosaurs that were more closely related to the birds than to the crocodiles.

    So I am learning more each day.
     
    • Informative Informative x 1
  15. Audie

    Audie Veteran Member

    Joined:
    Feb 18, 2018
    Messages:
    22,404
    Ratings:
    +11,612
    Religion:
    None
    A
    Its not an either / or.
    Some fish forvexample are partly warm
    blooded.
    Had to be a transition with quadrupeds.

    The Permian pelycosaurscwith that big
    fin back prolly were warmimg themselves in the
    sun.
    The what were they, cynodonts or something,the mammal like permian
    things must have been warm blooded
     
  16. exchemist

    exchemist Veteran Member

    Joined:
    Apr 24, 2018
    Messages:
    15,429
    Ratings:
    +15,651
    Religion:
    RC (culturally at least)
    Yes exactly, hence my query earlier about whether or not that was now settled.
     
    • Like Like x 1
  17. all souls loved

    Joined:
    Jan 22, 2022
    Messages:
    42
    Ratings:
    +14
    Religion:
    non-denominational
    There is no dino-bird connection. It is nothing but pseudoscience.

    If birds did evolve from land-based dinos, we should, at minimum, ask for examples of land-based dinos with partially-developed wings protruding from their backs.

    It is not enough for evolutionists to say we can't find such fossil samples because they are too rare...this is an excuse in the making. And a weak excuse at that.

    We have had hundreds of years to find such fossils if they existed. We have hundreds of millions of fossils in our museums all over the world but no land-based dinos with small wings sprouting out of their backs? Where are they?

    I am not comfortable with such excuses. Produce the transitional fossils or admit such transitional forms may not exist because they never did because the transition never occurred in the first place.
     
    #17 all souls loved, Jan 24, 2022
    Last edited: Jan 24, 2022
  18. all souls loved

    Joined:
    Jan 22, 2022
    Messages:
    42
    Ratings:
    +14
    Religion:
    non-denominational
    Archaeopteryx has no land-based dino features so does not qualify as a transitional form. A true transitional form is a land-based dino with partially formed wings sprouting from its back - something which has never been found, anywhere. This fact has been known for over 25 years now and has not changed one iota since then.

    "Paleontologists have tried to turn Archaeopteryx into an earth-bound, feathered dinosaur. But it's not. It is a bird, a perching bird. And no amount of ‘paleobabble’ is going to change that."

    Archaeopteryx: Early Bird Catches a Can of Worms by V. Morell, Science 259(5096):764–65.(1993).
     
  19. all souls loved

    Joined:
    Jan 22, 2022
    Messages:
    42
    Ratings:
    +14
    Religion:
    non-denominational
    Here is another article confirming Archaeopteryx is not a true transitional form because it has no land-based dino features. It's entire skeletal structure is air-based. This fact has been known for over 25 years now and has not changed since then.

    "Archaeopteryx probably cannot tell us much about the early origins of feathers and flight in true protobirds because Archaeopteryx was, in a modern sense, a bird."

    Science 259:790-793. (1993)
     
  20. all souls loved

    Joined:
    Jan 22, 2022
    Messages:
    42
    Ratings:
    +14
    Religion:
    non-denominational
    Here is an article proving the feathered dino theory is noting but an erroneous interpretation of fossils containing collagen striations which LOOKED like feathers to some people but were not feathers:

    The dinosaurian origin of feathers: perspectives from dolphin (Cetacea) collagen fibers.
    Lingham-Soliar T.
    Zoology Department, University of Durban-Westville, Private Bag X54001, 4000 Durban, KwaZulu-Natal, South Africa. [email protected]

    The early origin of birds is a hotly disputed debate and may be broadly framed as a conflict between paleontologists and ornithologists. The paleontological emphasis has shifted from Archaeopteryx and its origins to recent finds of Cretaceous birds and "feathered" dinosaurs from China. The identification of alleged feathers has, however, relied principally on the visual image. Some workers have interpreted these integumentary structures as collagen fibers. To test the latter hypothesis, using light microscopy, collagen from the hypodermis (blubber) and subdermal connective tissue sheath was examined from a dolphin that had been buried for a year as part of an experiment. Within the blubber, toward the central thicker parts of the material, the collagen fibers had compacted and the three-dimensional latticework of normal blubber had more or less collapsed. Chromatographic analysis of the blubber revealed pronounced oxidation of the unsaturated lipids, probably accounting for the collapse of the latticework. Fibers normally bound together in bundles became separated into individual fibers or smaller bundles by degradation of the glue-like substance binding them together. These degraded collagen fibers show, in many instances, feather-like patterns, strikingly reminiscent of many of those identified as either "protofeathers" or "modern" feathers in dromaeosaurid dinosaurs. The findings throw serious doubt on the virtually complete reliance on visual image by supporters of the feathered dinosaur thesis and emphasize the need for more rigorous methods of identification using modern feathers as a frame of reference. Since collagen is the main fiber type found in most supporting tissues, the results have wide implications regarding the degradation and fossilization of vertebrate integument, such as that of the ichthyosaurs, dinosaurs and birds.

    PMID: 14676953 [PubMed - indexed for MEDLINE]
     
Loading...