Announcement

Collapse

Natural Science 301 Guidelines

This is an open forum area for all members for discussions on all issues of science and origins. This area will and does get volatile at times, but we ask that it be kept to a dull roar, and moderators will intervene to keep the peace if necessary. This means obvious trolling and flaming that becomes a problem will be dealt with, and you might find yourself in the doghouse.

As usual, Tweb rules apply. If you haven't read them now would be a good time.

Forum Rules: Here
See more
See less

New Bird/Dinosaur intermediate species found

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Originally posted by lee_merrill
    Certainly, though in the case of the Cambrian explosion, the fossil record should show some intermediates--only it doesn't.
    Originally posted by lee_merrill
    I have read of the pre-Cambrian, and any intermediates (that I have seen) are speculative.
    I don't think you've actually looked at the fossil record of the pre-Cambrian. I think you've merely read creationist/ID summaries of it, and swallowed them wholesale.
    Jorge: Functional Complex Information is INFORMATION that is complex and functional.

    mikewhitney: What if the speed of light changed when light is passing through water? ... I have 3 semesters of college Physics.

    Mountain Man: First of all, the Bible is a fixed document.
    Mountain Man: … this is how liberals argue these days, with labels instead of ideas.

    Comment


    • #47
      Originally posted by shunyadragon View Post
      Your latest problem is incompletely citing a source: Fossil Museum?, a brief sound bite without a recognizable scientific reference nor credibility of context.

      What is your reference: Fossil Museum?
      It's from here. Easy to find because of the spelling error.

      But Dory's use of it is fallacious anyway. Just because trilobite and early arthropod ancestry is unresolved doesn't mean there aren't any intermediate fossils. It means that there are multiple potential intermediates, and we can't be sure which ones are the actual intermediates.

      This section from the article Dory claims to have read does contradict his earlier claim that there are no intermediates in the Cambrian explosion fossil record:
      The Naraoiidae is a family of early arthropods resembling trilobites in appearance. Because Naraoids had an entirely non-mineralized exoskeletons, they are often referred to as soft-bodied trilobites.
      as does the phylogenetic tree there and the pictures of naraoiids and helmetiids. I expect him to keep claiming there are no intermediates anyway.
      Last edited by Roy; 03-07-2019, 05:23 AM.
      Jorge: Functional Complex Information is INFORMATION that is complex and functional.

      mikewhitney: What if the speed of light changed when light is passing through water? ... I have 3 semesters of college Physics.

      Mountain Man: First of all, the Bible is a fixed document.
      Mountain Man: … this is how liberals argue these days, with labels instead of ideas.

      Comment


      • #48
        Adding to the mix:

        Source: SPRIGGINA IS A TRILOBITOID ECDYSOZOAN


        Convincingly specific homologies between Ediacarans and members of recognized animal phyla have remained elusive, thus casting a shadow of doubt over the animal affinity interpretation of Ediacaran phylogeny. Spriggina floundersi, for example, has been described as a tomopterid annelid, an arthropod, and a frondose vendobiont. Reanalysis of Spriggina demonstrates the presence of genal spines (comparable to those of fallotaspidoid and paradoxidid trilobites), a cephalic region homologous to the effaced cephalons of agraulid and skehanid trilobites, and a dual cephalic region (also seen in Parvancorina) that compares to the parts of a trilobite cephalon anterior and posterior of the facial suture. Spriggina is thus a trilobitoid ecdysozoan, a conclusion in accord with Sven Jorgen Birket-Smith�s inference of an arthropod affinity for Spriggina. This result is among the first confident phylogenetic linkages between an Ediacaran and a Cambrian animal, and thus helps to demonstrate that Paleozoic animals could indeed be descended from Ediacarans. If Spriggina is a direct ancestor of trilobites, then a case can be made that Spriggina itself (or a direct descendant) served as the predator taxon that initiated the Cambrian ecotone transformation (McMenamin, M. A. S., 2003, Origin and early evolution of predators: The ecotone model and early evidence for macropredation. In: P. Kelley, M. Kowalewski and T. Hansen, eds., Predator-Prey Interactions in the Fossil Record). Such heterotrophy, however, does not preclude the possibility of photosymbiosis or other types of mixotrophy in Ediacarans with high surface area such as Marywadea and Dickinsonia.


        Source

        © Copyright Original Source




        Sam 'Ohu Gon III a paleobiologist at the University of Hawaii at Manoa has an informative webpage Origins of Trilobites from which the following comes from

        Parvancorina: a Precambrian trilobite ancestor?
        00000000000000ab000-01c.jpg
        Parvancorina michami (left), Primicaris larvaformis (center), trilobite protaspis (right)

        The similarity of the Precambrian Parvancorina to the Cambrian Chengjiang arthropod Primicaris larvaformis, and a protaspid of a Cambrian trilobite is seen to the left[1]. All three have an ovoid form, and an anchor-like structure made up of an axial lobe and lateral lobes running along the anterior and lateral edges of the body. Primicaris was first thought to be a larval naraoid (e.g., Hou & Bergstrom 1997), but it was recognized more recently as taxon in its own right (Zhang et al 2003). Recapitulating phylogeny, the trilobite protaspid resembles Primicaris. If the similarity of Parvancorina to Primicaris is more than superficial, it is perhaps the best candidate for an early arthropod in the Precambrian.


        He also has this explanatory illustration

        From Parvancorina to Trilobite in Four Easy Steps:
        00000000000000a00a.gif


        Personally, I agree that the link is still tentative but it is more than sufficient to demonstrate that there is no evidence of intermediaries is hogswallop.

        For a bit more on potential intermediates from Precambrian to Cambrian organisms

        Source: A Parvancorina-like arthropod from the Cambrian of South China


        Abstract

        Constraining the origin of animal groups is allowed, to some extent, by discoveries of Cambrian Lagerstätten that preserve both mineralizing and nonmineralizing organisms. A new species is reported here of the Cambrian arthropod Skania, which bears an exoskeleton that shares homologies with the Neoproterozoic (Ediacaran) organism Parvancorina and firmly establishes a Precambrian root for arthropods. A new monophyletic group, Parvancorinomorpha, is proposed as the first clade within the arthropod crown group demonstrably ranging across the Neoproterozoic–Paleozoic transition. The Parvancorinomorpha is interpreted to be the sister group of the Arachnomorpha. Incipient cephalization in Skania and related genera represents a step in the progression toward division of a cephalon from a large posterior trunk as shown in Cambrian arachnomorphs such as naraoiids and the addition of a pygidium and thoracic tergites as shown in the arachnomorph clade basal to trilobites. This evidence can serve as a new calibration point for estimating the divergence time for the last common ancestor of arthropods and priapulids based on molecular clock methods.


        Source

        © Copyright Original Source







        1 I moved the illustration from the left to above in this post
        Last edited by rogue06; 03-07-2019, 06:56 AM.

        I'm always still in trouble again

        "You're by far the worst poster on TWeb" and "TWeb's biggest liar" --starlight (the guy who says Stalin was a right-winger)
        "Of course, human life begins at fertilization that’s not the argument." --Tassman

        Comment


        • #49
          Originally posted by Roy View Post
          It's from here. Easy to find because of the spelling error.

          But Dory's use of it is fallacious anyway. Just because trilobite and early arthropod ancestry is unresolved doesn't mean there aren't any intermediate fossils. It means that there are multiple potential intermediates, and we can't be sure which ones are the actual intermediates.

          This section from the article Dory claims to have read does contradict his earlier claim that there are no intermediates in the Cambrian explosion fossil record:
          The Naraoiidae is a family of early arthropods resembling trilobites in appearance. Because Naraoids had an entirely non-mineralized exoskeletons, they are often referred to as soft-bodied trilobites.
          as does the phylogenetic tree there and the pictures of naraoiids and helmetiids. I expect him to keep claiming there are no intermediates anyway.
          Thank you for putting the reference in context. The reference is good, but more a summary of the present classification based on the fossil evidence.

          This is a classic Lee's habit of using out of context 'sound bites' to justify his agenda that do not reflect the whole reference, nor in context of the overall knowledge of the overall evolution in the given period of time. This reflects an out of context 'argument from ignorance.' and a reflection of Lee's lack of knowledge.
          Glendower: I can call spirits from the vasty deep.
          Hotspur: Why, so can I, or so can any man;
          But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

          go with the flow the river knows . . .

          Frank

          I do not know, therefore everything is in pencil.

          Comment


          • #50
            Originally posted by shunyadragon View Post
            This is a classic Lee's habit of using out of context 'sound bites' to justify his agenda that do not reflect the whole reference, nor in context of the overall knowledge of the overall evolution in the given period of time. This reflects an out of context 'argument from ignorance.' and a reflection of Lee's lack of knowledge.
            Lack of knowledge isn't the problem. Lack of awareness of lack of knowledge isn't even the problem. Lack of willingness to remedy lack of knowledge is the problem.
            Jorge: Functional Complex Information is INFORMATION that is complex and functional.

            mikewhitney: What if the speed of light changed when light is passing through water? ... I have 3 semesters of college Physics.

            Mountain Man: First of all, the Bible is a fixed document.
            Mountain Man: … this is how liberals argue these days, with labels instead of ideas.

            Comment


            • #51
              Originally posted by rogue06 View Post
              For a bit more on potential intermediates from Precambrian to Cambrian organisms

              Source: A Parvancorina-like arthropod from the Cambrian of South China


              Abstract

              Constraining the origin of animal groups is allowed, to some extent, by discoveries of Cambrian Lagerstätten that preserve both mineralizing and nonmineralizing organisms. A new species is reported here of the Cambrian arthropod Skania, which bears an exoskeleton that shares homologies with the Neoproterozoic (Ediacaran) organism Parvancorina and firmly establishes a Precambrian root for arthropods. A new monophyletic group, Parvancorinomorpha, is proposed as the first clade within the arthropod crown group demonstrably ranging across the Neoproterozoic–Paleozoic transition. The Parvancorinomorpha is interpreted to be the sister group of the Arachnomorpha. Incipient cephalization in Skania and related genera represents a step in the progression toward division of a cephalon from a large posterior trunk as shown in Cambrian arachnomorphs such as naraoiids and the addition of a pygidium and thoracic tergites as shown in the arachnomorph clade basal to trilobites. This evidence can serve as a new calibration point for estimating the divergence time for the last common ancestor of arthropods and priapulids based on molecular clock methods.


              Source

              © Copyright Original Source

              Yet we read here:

              Source: Ediacaran.org

              Parvancorina, from the Latin parva ancora (small anchor), was a small anchor-shaped organism that lived on the Ediacaran seafloor. Parvancorina has been suggested to be an ancestor of living arthropods (the group that includes modern crabs, shrimp and insects), however its phylogenetic placement is uncertain at present.


              Source

              © Copyright Original Source


              Blessings,
              Lee
              "What I pray of you is, to keep your eye upon Him, for that is everything. Do you say, 'How am I to keep my eye on Him?' I reply, keep your eye off everything else, and you will soon see Him. All depends on the eye of faith being kept on Him. How simple it is!" (J.B. Stoney)

              Comment


              • #52
                Originally posted by lee_merrill View Post
                Yet we read here:

                Source: Ediacaran.org

                Parvancorina, from the Latin parva ancora (small anchor), was a small anchor-shaped organism that lived on the Ediacaran seafloor. Parvancorina has been suggested to be an ancestor of living arthropods (the group that includes modern crabs, shrimp and insects), however its phylogenetic placement is uncertain at present.


                Source

                © Copyright Original Source


                Blessings,
                Lee
                As I noted:

                Personally, I agree that the link is still tentative but it is more than sufficient to demonstrate that there is no evidence of intermediaries is hogswallop.

                [*Emphasis added*]

                I'm always still in trouble again

                "You're by far the worst poster on TWeb" and "TWeb's biggest liar" --starlight (the guy who says Stalin was a right-winger)
                "Of course, human life begins at fertilization that’s not the argument." --Tassman

                Comment


                • #53
                  Originally posted by lee_merrill View Post
                  Yet we read here:

                  Source: Ediacaran.org

                  Parvancorina, from the Latin parva ancora (small anchor), was a small anchor-shaped organism that lived on the Ediacaran seafloor. Parvancorina has been suggested to be an ancestor of living arthropods (the group that includes modern crabs, shrimp and insects), however its phylogenetic placement is uncertain at present.


                  Source

                  © Copyright Original Source


                  Blessings,
                  Lee
                  What is wrong with ' phylogenetic placement is uncertain at present'? Are you proposing your SOP selective 'arguing from ignorance.'
                  Glendower: I can call spirits from the vasty deep.
                  Hotspur: Why, so can I, or so can any man;
                  But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                  go with the flow the river knows . . .

                  Frank

                  I do not know, therefore everything is in pencil.

                  Comment


                  • #54
                    Another dinosaur bird intermediate found in the raptor family.

                    Source: https://news.nationalgeographic.com/2015/09/150905-animals-sleep-science-dreaming-cats-brains/



                    Meet Lori, a tiny dinosaur that may help explain how birds evolved flight

                    The chicken-size carnivore from the late Jurassic is already ruffling feathers among paleontologists.

                    A fluffy, three-foot-long killer found in Wyoming is the oldest known relative of Velociraptor discovered in North America, paleontologists announced today. Named Hesperornithoides miessleri, the ancient animal is also the smallest dinosaur yet found in the state, which until now has been known for fossils of celebrity behemoths such as Brachiosaurus, Diplodocus, and Stegosaurus.

                    The newly described dinosaur, reported today in the journal PeerJ, specifically comes from a layer of roughly 150-million-year-old rocks called the Morrison Formation, which covers a vast swath of the western U.S. centered on Wyoming and Colorado.

                    “When you’re working in the Morrison, you’re expecting to only find big stuff—even an isolated vertebra of Diplodocus is almost as big as this entire skeleton,” says study coauthor Dean Lomax, a paleontologist at the University of Manchester in the U.K. This diminutive fossil, he says, “demonstrates that the Morrison Formation was more diverse than previously known … and shows that there were little dinosaurs around.”


                    Over a thousand dinosaur species once roamed the Earth. Learn which ones were the largest and the smallest, what dinosaurs ate and how they behaved, as well as surprising facts about their extinction. But the description of Hesperornithoides may ruffle some feathers among paleontologists, as the study authors argue that it hints the first flying ancestors of birds evolved among ground-dwelling dinosaurs, rather than tree-dwelling dinosaurs that could climb and glide.

                    Fluffy little murderbird

                    Wyoming’s smallest known dinosaur was found by accident during a 2001 fossil dig to uncover the bones of its largest, a 111-foot-long sauropod called Supersaurus. A shovel went through Hesperornithoides’ snout, unfortunately destroying part of it, as surface layers of soil were removed to reach the larger bones of Supersaurus.

                    When the dig crew first uncovered the fossil, they thought it might be a pterosaur, a flying reptilian contemporary of the dinosaurs, based on the minute size of the bones. It was only after careful preparation that they realized the find’s full significance.

                    © Copyright Original Source

                    Glendower: I can call spirits from the vasty deep.
                    Hotspur: Why, so can I, or so can any man;
                    But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                    go with the flow the river knows . . .

                    Frank

                    I do not know, therefore everything is in pencil.

                    Comment


                    • #55
                      A bony toothed bird 62 million years old is another link between feathered flying dinosaurs and birds.

                      Source: http://www.sci-news.com/paleontology/protodontopteryx-ruthae-07603.html



                      Dubbed Protodontopteryx ruthae, the ancient seabird belongs to Pelagornithidae, an ancient family of bony-toothed birds.

                      These seafaring birds were previously known from late Paleocene to Pliocene fossil sites and some species reached wingspans up to 6.4 m (21 feet).

                      Protodontopteryx ruthae is the oldest, but smallest member in the family.

                      It was only the size of an average gull and, like other pelagornithids, had bony, tooth-like projections on the edge of its beak.

                      The partial skeleton of Protodontopteryx ruthae was found by amateur paleontologist Leigh Love at the Waipara Greensand fossil site in 2018.

                      “The age of the fossilized bones suggests pelagornithids evolved in the Southern Hemisphere,” said Dr. Paul Scofield, a curator at Canterbury Museum and the senior author of a paper published in the journal Papers in Palaeontology.

                      “While this bird was relatively small, the impact of its discovery is hugely significant in our understanding of this family.”

                      “Until we found this skeleton, all the really old pelagornithids had been found in the Northern Hemisphere, so everyone thought they’d evolved up there.”

                      “New Zealand was a very different place when Protodontopteryx ruthae were in the skies. It had a tropical climate — the sea temperature was about 25 degrees Celsius (77 degrees Fahrenheit) so we had corals and giant turtles.”



                      “The discovery of Protodontopteryx ruthae was truly amazing and unexpected,” said co-author Dr. Gerald Mayr, a researcher with the Senckenberg Research Institute and Natural History Museum.

                      “Not only is the fossil one of the most complete specimens of a pseudotoothed bird, but it also shows a number of unexpected skeletal features that contribute to a better understanding of the evolution of these enigmatic birds.”

                      The skeleton of Protodontopteryx ruthae suggests it was less suited for long-distance soaring than later pelagornithids and probably covered much shorter ranges.

                      Its short, broad pseudoteeth were likely designed for catching fish. Later species had needle-like pseudoteeth which were likely used to catch soft-bodied prey like squid.

                      “Because Protodontopteryx ruthae was less adapted to sustained soaring than other known pelagornithids, we can now say that pseudoteeth evolved before these birds became highly specialized gliders,” said co-author Dr. Vanesa De Pietri, a curator at Canterbury Museum.

                      Gerald Mayr et al. Oldest, smallest and phylogenetically most basal pelagornithid, from the early Paleocene of New Zealand, sheds light on the evolutionary history of the largest flying birds. Papers in Palaeontology, published online September 17, 2019; doi: 10.1002/spp2.1284

                      © Copyright Original Source

                      Glendower: I can call spirits from the vasty deep.
                      Hotspur: Why, so can I, or so can any man;
                      But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                      go with the flow the river knows . . .

                      Frank

                      I do not know, therefore everything is in pencil.

                      Comment


                      • #56
                        Another discovery of an intermediate between Avian dinosaurs and birds found.

                        Source: https://www.smithsonianmag.com/science-nature/newly-discovered-fossil-bird-fills-gap-between-dinosaurs-and-modern-fliers-180973551/



                        Newly Discovered Fossil Bird Fills in Gap Between Dinosaurs and Modern Fliers

                        A skeleton from the Cretaceous found in Japan reveals an early bird with a tail nub resembling the avians of today
                        image: https://thumbs-prod.si-cdn.com/4goWk...eryx-prima.jpg


                        Birds are ancient creatures. Every hawk, sparrow, pigeon and penguin alive today has ancestral roots dating back to the Jurassic, when the first birds were just another form of raptor-like dinosaur. Dozens of fossils uncovered and described during the last three decades have illuminated much of this deep history, but the rock record can still yield surprises. A fossil recently found in Japan is one such unexpected avian that raises questions about what else may await discovery.

                        The skeleton, named Fukuipteryx prima, was described by Fukui Prefectural University paleontologist Takuya Imai and colleagues today in Communications Biology. And while numerous birds of similar geologic age have been named in the past few decades, the details of these bones and where they were found have experts a-flutter.

                        The 120 million-year-old fossil was discovered in the summer of 2013 while searching for fossils at Japan’s Kitadani Dinosaur Quarry. “One of my colleagues at Fukui Prefectural Dinosaur Museum spotted tiny bones in a block of siltstone,” Imai says. At the time, it wasn’t clear what creature the bones belonged to, but once the encasing rock was chipped away, the structure of the fossil became clear. The skeleton was an early bird, and an unusual one at that.

                        Small bodies and hollow bones have made birds relatively rare finds in the fossil record. Only a few unique fossil deposits, like China’s 125 million-year-old Jehol Biota or the United States’ 50 million-year-old Green River Formation, allow paleontologists to get a good look at ancient avians. To find a well-preserved fossil bird outside such places of exceptional preservation represents a noteworthy paleontological discovery, and Fukuipteryx in Japan adds another significant spot on the map for fossil birds.


                        Read more: https://www.smithsonianmag.com/scien...t1MAOts3SHS.99
                        Give the gift of Smithsonian magazine for only $12! http://bit.ly/1cGUiGv

                        © Copyright Original Source

                        Glendower: I can call spirits from the vasty deep.
                        Hotspur: Why, so can I, or so can any man;
                        But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                        go with the flow the river knows . . .

                        Frank

                        I do not know, therefore everything is in pencil.

                        Comment


                        • #57
                          Added note: These and other discoveries of avian dinosaurs and transitional species to birds and primitive birds existed in the Cretaceous forests. There is not only a progressive evolution in this time period, but also many variations existed in the forests at the same time.
                          Glendower: I can call spirits from the vasty deep.
                          Hotspur: Why, so can I, or so can any man;
                          But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                          go with the flow the river knows . . .

                          Frank

                          I do not know, therefore everything is in pencil.

                          Comment


                          • #58
                            New discovery reveals an important advancement in the evolution of the beak in birds

                            Source: https://stockdailydish.com/scientists-make-new-discovery-about-bird-evolution/



                            Scientists make new discovery about bird evolution
                            Posted by SDD Contributor on December 15, 2019 at 8:50 am
                            Credit: CC0 Public Domain

                            In a new paper published in National Science Review, a team of scientists from the Institute of Vertebrate Paleontology and Paleoanthropology, the Shandong Tianyu Museum of Nature, and the Nanjing Institute of Geology and Paleontology (all in China) described the most exceptionally preserved fossil bird discovered to date.

                            The new specimen from the rich Early Cretaceous Jehol Biota (approximately 131 to 120 million years old) is referred to as Eoconfuciusornis, the oldest and most primitive member of the Confuciusornithiformes, a group of early characterized by the first occurrence of an avian beak. Its younger relative Confuciusornis is known from thousands of specimens but this is only the second specimen of Eoconfuciusornis found. This species comes only from the 130.7 Ma Huajiying Formation deposits in Hebei, which preserves the second oldest known fossil birds. Birds from this layer are very rare.

                            This new specimen of Eoconfuciusornis, housed in the Shandong Tianyu Museum of Nature, in Eastern China, is a female. The ovary reveals developing yolks that vary in size, similar to living birds. This suggests that confuciusornithiforms evolved a period of rapid yolk deposition prior to egg-laying (crocodilians, which are archosaurs like birds, deposit yolks slowly in all eggs for months with no period of rapid yolk formation), which is indicative of complex energetic profiles similar to those observed in birds.

                            © Copyright Original Source

                            Glendower: I can call spirits from the vasty deep.
                            Hotspur: Why, so can I, or so can any man;
                            But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                            go with the flow the river knows . . .

                            Frank

                            I do not know, therefore everything is in pencil.

                            Comment


                            • #59
                              A beaked toothless flightless avian dinosaur with two toes found.

                              Source: https://scitechdaily.com/newly-discovered-toothless-two-fingered-dinosaurs-lost-digits-point-to-spread-of-parrot-like-species/



                              Newly Discovered Toothless, Two-Fingered Dinosaur’s Lost Digits Point to Spread of Parrot-Like Species

                              TOPICS:DinosaursEvolutionPaleontologyUniversity Of Edinburgh
                              By UNIVERSITY OF EDINBURGH OCTOBER 6, 2020

                              Three Oksoko avarsan dinosaurs. Credit: Michael W. Skrepnick

                              A newly discovered species of toothless, two-fingered dinosaur has shed light on how a group of parrot-like animals thrived more than 68 million years ago.

                              The unusual species had one less finger on each forearm than its close relatives, suggesting an adaptability which enabled the animals to spread during the Late Cretaceous Period, researchers say.

                              Multiple complete skeletons of the new species were unearthed in the Gobi Desert in Mongolia by a University of Edinburgh-led team.

                              Remains of three dinosaurs preserved resting together. Credit: Gregory Funston

                              Named Oksoko avarsan, the feathered, omnivorous creatures grew to around two meters long and had only two functional digits on each forearm. The animals had a large, toothless beak similar to the type seen in species of parrot today.

                              The remarkably well-preserved fossils provided the first evidence of digit loss in the three-fingered family of dinosaurs known as oviraptors.

                              The discovery that they could evolve forelimb adaptations suggests the group could alter their diets and lifestyles, and enabled them to diversify and multiply, the team says.

                              Researchers studied the reduction in size, and eventual loss, of a third finger across the oviraptors’ evolutionary history. The group’s arms and hands changed drastically in tandem with migrations to new geographic areas — specifically to what is now North America and the Gobi Desert.

                              Fossil of Oksoko avarsan’s two-fingered hand. Credit: Gregory Funston

                              The team also discovered that Oksoko avarsan — like many other prehistoric species — were social as juveniles. The fossil remains of four young dinosaurs were preserved resting together.

                              The study, published in the journal Royal Society Open Science, was funded by The Royal Society and the Natural Sciences and Engineering Council of Canada. It also involved researchers from the University of Alberta and Philip J. Currie Dinosaur Museum in Canada, Hokkaido University in Japan, and the Mongolian Academy of Sciences.

                              Dr. Gregory Funston, of the University of Edinburgh’s School of GeoSciences, who led the study, said: “Oksoko avarsan is interesting because the skeletons are very complete and the way they were preserved resting together shows that juveniles roamed together in groups. But more importantly, its two-fingered hand prompted us to look at the way the hand and forelimb changed throughout the evolution of oviraptors–which hadn’t been studied before. This revealed some unexpected trends that are a key piece in the puzzle of why oviraptors were so diverse before the extinction that killed the dinosaurs.”

                              © Copyright Original Source


                              Glendower: I can call spirits from the vasty deep.
                              Hotspur: Why, so can I, or so can any man;
                              But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                              go with the flow the river knows . . .

                              Frank

                              I do not know, therefore everything is in pencil.

                              Comment


                              • #60
                                Another odd bird found in the Cretaceous adds to the diversity of evolving birds.

                                Source: https://phys.org/news/2020-11-bird-tall-sickle-shaped-beak-reveals.html




                                Bird with tall, sickle-shaped beak reveals hidden diversity during the age of dinosaurs


                                by Ohio University
                                Illustration depicting the early bird Falcatakely amidst nonavian dinosaurs and other creatures during the Late Cretaceous in Madagascar. Credit: Mark Witton.
                                A Cretaceous-age, crow-sized bird from Madagascar would have sliced its way through the air wielding a large, blade-like beak and offers important new insights on the evolution of face and beak shape in the Mesozoic forerunners of modern birds. An international team of researchers led by Ohio University professor Dr. Patrick O'Connor and Stony Brook University professor Dr. Alan H. Turner announced the discovery today in the journal Nature.

                                Birds have played a pivotal role in shaping our understanding of biological evolution. As long ago as the mid-19th Century, Charles Darwin's keen observations on the diversity of beak shape in Galapagos finches influenced his treatise on evolution through natural selection. This fossil bird discovery adds a new twist on the evolution of skulls and beaks in birds and their close relatives, showing that evolution can work through different developmental pathways to achieve similar head shapes in very distantly related animals.

                                The bird is named Falcatakely, a combination of Latin and Malagasy words inspired by the small size and the sickle-shaped beak, the latter representing a completely novel face shape in Mesozoic birds. The species is known from a single well-preserved, nearly complete skull, one that was buried in a muddy debris flow around 68 million years ago. Bird skeletons are rare in the fossil record because of their lightweight bones and small size. Bird skulls are an even rarer find. Falcatakely is the second Cretaceous bird species discovered in Madagascar by the National Science Foundation-funded team.

                                The delicate specimen remains partially embedded in rock due to the complex array of lightly built bones that make up the skull. Although quite small, with an estimated skull length of only 8.5 cm (~ 3 inches), the exquisite preservation reveals many important details. As one example, a complex series of grooves on the bones making up the side of the face indicate that the animal hosted an expansive keratinous covering, or beak, in life.
                                Play.

                                "As the face began to emerge from the rock, we knew that it was something very special, if not entirely unique," notes Patrick O'Connor, professor of anatomy and neuroscience at Ohio University and lead author on the study. "Mesozoic birds with such high, long faces are completely unknown, with Falcatakely providing a great opportunity to reconsider ideas around head and beak evolution in the lineage leading to modern birds."

                                Falcatakely belongs to an extinct group of birds called Enantiornithes, a group known exclusively from the Cretaceous Period and predominantly from fossils discovered in Asia. "Enantiornithines represent the first great diversification of early birds, occupying ecosystems alongside their non-avian relatives such as Velociraptor and Tyrannosaurus," says Turner, an associate professor of anatomical sciences at Stony Brook University and study co-author. "Unlike the first birds, such as Archaeopteryx, with long tails and primitive features in the skull, enantiornithines like Falcatakely would have looked relatively modern."

                                © Copyright Original Source



                                Glendower: I can call spirits from the vasty deep.
                                Hotspur: Why, so can I, or so can any man;
                                But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                                go with the flow the river knows . . .

                                Frank

                                I do not know, therefore everything is in pencil.

                                Comment

                                Related Threads

                                Collapse

                                Topics Statistics Last Post
                                Started by TheLurch, 01-18-2021, 12:27 PM
                                7 responses
                                32 views
                                1 like
                                Last Post TheLurch  
                                Started by lee_merrill, 01-16-2021, 03:43 PM
                                2 responses
                                33 views
                                0 likes
                                Last Post TheLurch  
                                Started by rogue06, 01-15-2021, 04:43 PM
                                8 responses
                                50 views
                                1 like
                                Last Post rogue06
                                by rogue06
                                 
                                Started by TheLurch, 01-15-2021, 07:40 AM
                                19 responses
                                71 views
                                0 likes
                                Last Post shunyadragon  
                                Started by Cow Poke, 01-13-2021, 04:55 PM
                                5 responses
                                27 views
                                0 likes
                                Last Post mossrose  
                                Working...
                                X