Read Ebook {PDF EPUB} Feathered Dinosaurs The Origin of Birds by John A. Long A Dinosaur A Day. Classification : Dinosauromorpha, Dinosauriformes, Dracohors, Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoromorpha. Status : Extinct. Time and Place : Between 154 and 147 million years ago, from the Kimmeridgian to the Tithonian ages of the Late Jurassic. Ornitholestes is known from the Brushy Basin and Lake Como members of the Morrison Formation in Colorado and Wyoming. Physical Description : Ornitholestes was a small, bipedal carnivore, a coelurosaur - so the kind of dinosaur that would evolve into birds, raptors, and many more. Of course, raptors and proto-birds already existed by the time Ornitholestes did, so Ornitholestes was not their ancestor - but it sure looked a lot like it. Still, at first glance, Ornitholestes wouldn’t have looked much different from your average, run-of-the-mill small theropod like we’d see previously in the history of life. It was small, it had a long tail and long arms, a long head, and a short neck. It was covered in simple protofeathers, very little of which was doing anything different from protofeathers seen before. However, looking closer, more could be seen on this little dinosaur. As a Maniraptoromorph - very close to when dinosaurs began to get really birdlike - Ornitholestes would have begun to show some of the initial characteristics of birds. It’s possible that it may have had the beginnings of elongated feathers on its arms - the start of wings. This is supported by the fact that it had long forelimbs - giving it ample surface to display feathers to members of the group. It also had fairly short hind legs - making it rather slow, slower than most previous theropods. It’s even possible it may have been more of a kicker than a runner, using its toe claws in defense and attack - and there are hypotheses that it may have had a sickle claw like later raptors and early birds did. Early portrayals of Ornitholestes maintained that it had a crest on its nose, given a raised bone in the front of the snout. However, this has not been well preserved and thus remains a hypothesis more than a fact. Most consider the presence of the crest or horn to be rather unlikely. Still, it would have been a fairly fancy looking dinosaur, and one - between its long arms, and shorter legs - that showed what was to come in dinosaur evolution. Diet : Ornitholestes was probably mainly carnivorous, given its teeth being serrated and sharp. Still, the ancestor of Coelurosaurs was probably omnivorous, making it possible that Ornitholestes may have supplemented its diet with plant material from time to time. Behavior : Ornitholestes probably would have been more of a hopping predator, walking slowly through the floodplains and forests to track prey and jumping to catch it with its large grasping hands. The hands of Ornitholestes were able to extend together and then bend in together to grasp food, allowing it to hold prey in both hands - a trait that isn’t actually present in earlier theropods, at least, not to the same extent. The tail would have helped it to stay in balance while hunting. It probably would then hold the food and eat it, and thus stuck to smaller prey such as lizards, mammals, and baby dinosaurs. Since it had a short neck, it’s unlikely that it would have used its head much to grab food - its arms were unencumbered with large wings, and thus, it wouldn’t have had to avoid using them. Given that Ornitholestes is fairly rare to find in the Morrison Formation - a geologic system famous for having way too many dinosaur fossils - it seems unlikely that Ornitholestes was particularly social, as it would theoretically be found in groups if it was. Instead, it was probably a loner, spending most of its time on its own and hunting for food. Given that, as a dinosaur, it probably still took care of its young - its possible that solitary Ornitholestes mothers would just raise their young until they were old enough to fend for themselves, or the father would like in modern ratites. Either way, the social groups seen in later birdie dinosaurs like the Ornithomimosaurs and Raptors (much less birds) probably wasn’t seen in Ornitholestes . Ecosystem : Ornitholestes is from the Morrison Formation, one of the two most famous ecosystems with non-avian dinosaurs (the other being the Late Cretaceous Hell Creek formation). It was famous for its iconic animals - mostly sauropods, but also dinosaurs such as Stegosaurus and Allosaurus - that have become the stereotypical Jurassic picture of dinosaurs. This environment was a very large, semi-arid plain surrounding a system of rivers, which would dry up seasonally and flood afterwards, creating very muddy environments. There was also a giant salt lake - called Lake T’oo’dishi’ - and volcanoes that would cover the plain in ash. There were plenty of ginkgo trees, as well as cycads, conifers, ferns, horsetails, cycadeoids, and tree ferns. Forests would pepper the plains, which would have been dominated with ferns and other low growing plants, as grass wasn’t around yet. It is nearly impossible to list all the animals we know lived in the Morrison - and plenty of them probably weren’t concurrent with Ornitholestes . Between that and the fact that the individual subunits of the Morrison are not really well diagrammed, I’m going to give us all my best guesses - important things found in roughly the same locations as Ornitholestes . The Brushy Basin Member of Colorado and Wyoming was by far the more diverse and better studied of the two where Ornitholestes has been found. There were other Coelurosaurs like Coelurus itself, as well as the early tyrannosaur Stokesosaurus , both of which being very similar in external appearance to Ornitholestes . There were also larger theropods like Allosaurus , Torvosaurus , Marshosaurus , and Ceratosaurus , which would have been real and present dangers to Ornitholestes . There were, of course, the iconic sauropods of the Morrison - Brachiosaurus and Camarasaurus ; Supersaurus , Barosaurus , and Diplodocus ; and, of course, Apatosaurus and Brontosaurus . Ornitholestes probably would have fed on babies from these dinosaurs, as well as eggs, which would have been small enough to be sources of food. There were Ornithischians as well - the smaller Dryosaurus , Nanosaurus , and Fruitadens probably would have made good food for Ornitholestes ; whereas the larger ornithopod Camptosaurus would have been a big no-no. Extreme dangerous would have come from the armored dinosaurs Stegosaurus , Hesperosaurus , Alcovasaurus , and Mymoorapelta . There were, of course, many non-dinosaurs in the Brushy Basin member as well, which would have probably made up more of Ornitholestes’ diet than dinosaurs would have - just, you know, size-wise. There were pterosaurs like Mesadactylus, Kepodactylus, and Harpactognathus ; stem- crocodiles of all shapes and sizes like Amphicotylus, Diplosaurus, Eutretauranosuchus, Fruitachampsa, Hallopus, and Maceloganthus ; and turtles like Dinochelys, Dorsetochelys, and Glyptops . Lepidosaurs were common too - the earliest known snake, Diablophis , was present in the same area as Ornitholestes ; there were also lizards like Dorsetisaurus, Paramacellodus, and Saurillodon ; and tuatara relatives like Eilenodon, Opisthias, and Theretairus . There was also a Choristodere, Cteniiogenys . But, the big stars of the Morrison aren’t any sort of reptile - not even dinosaurs - but rather, the mammals. The Morrison showcases Mammalian evolution in the late Jurassic, and has mamals from across the whole group at that point in time. A lot of these would have made good food for Ornitholestes , though they came in a wide variety of shapes and sizes and ease-of- catching. There was Amphidon, Tinodon, Aploconodon, Comodon, Trioracodon, Ctenacodon, Glirodon, Priacodon, Psalodon, Docodon, Fruitafossor, Amblotherium, Archaeotrigon, Comotherium, Dryolestes, Euthalastus, Laolestes, Paurodon, and Tathiodon - just to name a few. There was an early frog, Enneabatrachus , and an early salamander, Iridotriton , as well, and some grasshoppers. The Lake Como Member of Wyoming was much less intense, and much less diverse. Coelurus and another early coelurosaur, Tanycolagreus , were present here; as well as the large predator Allosaurus . Sauropods included Brachiosaurus, Brontosaurus, Camarasaurus, Galeamopus, and Diplodocus . Ornithischians included Dryosaurus, Stegosaurus , and Camptosaurus . There were a few non-dinosaurs as well: the turtle Glyptops , and the stem-crocodiles Eutretauranosuchus and Goniopholis . So, similar to the Brushy Basin - but more sparse, possibly reflecting some sort of environmental change or extinction, or - since it was mostly concurrent with the Brushy Basin, and only sometimes a little bit younger - a more harsh environment than the general location of the Brushy Basin. Other : Ornitholestes is probably more famous than it deserves to be thanks to Walking With Dinosaurs. I mean, seriously guys, this thing is really only known from like, one confirmed and two possible skeletons. It was not common. But it is still pretty cool. By Meig Dickson. Sources under the Cut. Britt, B. 1991. Theropods of Dry Mesa Quarry (Morrison Formation, Late Jurassic), Colorado, with emphasis on the osteology of Torvosaurus tanneri. BYU Geology Studies 37:1-72. Caldwell, M. W.; Nydam, R. L.; Palci, A.; Apesteguía, S. N. (2015). “The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution”. Nature Communications. 6: 5996. Carpenter, Kenneth; Miles, Clifford; Ostrom, John H.; Cloward, Karen (2005). “Redescription of the Small Maniraptoran Theropods Ornitholestes and Coelurus”. In Carpenter, Kenneth. The Carnivorous Dinosaurs. Life of the Past. Indiana University Press. pp. 49–71. Carpenter, Kenneth; Miles, Clifford; Cloward, Karen (2005). “New Small Theropod from the Upper Jurassic Morrison Formation of Wyoming”. In Carpenter, Kenneth. The Carnivorous Dinosaurs. Life of the Past. Indiana University Press. pp. 23–48. Carrano, M. T., and J. Velez-Juarbe. 2006. Paleoecology of the Quarry 9 vertebrate assemblage from Como Bluff, Wyoming (Morrison Formation, Late Jurassic). Palaeogeography, Palaeoclimatology, Palaeoecology 234(2-4):147-159. Chure, Daniel (1998). “On the Orbit of Theropod Dinosaurs” Gaia (18): 233–240. Fastovsky, David E.; Weishampel, David B. (2005). “Theropoda I: Nature red in tooth and claw”. The Evolution and Extinction of the Dinosaurs. Cambridge University Press. pp. 265–299. Foster, J. (2007). Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. Galiano, H., and R. Albersdörfer. 2010. A New Basal Diplodocoid Species, Amphicoelias brontodiplodocus from the Morrison Formation, Big Horn Basin, Wyoming, with Taxonomic Reevaluation of Diplodocus, Apatosaurus, Barosaurus and Other Genera. Dinosauria International (Ten Sleep, WY) Report for September 2010 1-41. Glut, Donald F. (1997). “Ornitholestes”. Dinosaurs: The Encyclopedia. McFarland & Company. pp. 643–646. Holtz, Thomas R.; Molnar, Ralph E.; Currie, Philip J. (2004). “Basal Tetanurae”. In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka. The Dinosauria: Second Edition. University of California Press. pp. 71–110. Lambert, David (1993). “Ornitholestes”. The Ultimate Dinosaur Book. Dorling Kindersley. pp. 78–79. Long, John A.; Schouten, Peter (2008). “Ornitholestes and kin”. Feathered Dinosaurs: The Origin of Birds. Oxford University Press. pp. 72–77. Norman, David B. (1985). “Coelurosaurs”. The Illustrated Encyclopedia of Dinosaurs. Salamander Books Ltd. pp. 38–43. Norman, David B. (1990). “Problematic Theropoda: Coelurosaurs”. In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka. The Dinosauria. University of California Press. pp. 280–305. Osborn, Henry Fairfield (1903). “Ornitholestes hermanni, a new compsognathoid dinosaur from the Upper Jurassic”. Bulletin of the American Museum of Natural History. 19 (12): 459–464. Osborn, Henry Fairfield (1917). “Skeletal adaptations of Ornitholestes, Struthiomimus, Tyrannosaurus”. Bulletin of the American Museum of Natural History. 35 (43): 733–771. Ostrom, John H. (1969). “Osteology of Deinonychus antirrhopus, an unusual theropod from the Lower Cretaceous of Montana”. Peabody Museum of Natural History Bulletin. 30: 1–165. Ostrom, John H. (1980). “Coelurus and Ornitholestes: Are they the same?”. In Jacobs, Louis L. Aspects of Vertebrate History: Essays in Honor of Edwin Harris Colbert. Museum of Northern Arizona Press. pp. 245–256. Paul, Gregory S. (1988). “Ornitholestians and Allosaurs”. Predatory Dinosaurs of the World. Simon & Schuster. pp. 302–318. Paul, Gregory S. (1988). “The small predatory dinosaurs of the mid-Mesozoic: The horned theropods of the Morrison and Great Oolite— Ornitholestes and Proceratosaurus—and the sickle-claw theropods of the Cloverly, Djadokhta and Judith River—Deinonychus, Velociraptor and Saurornitholestes”. Hunteria. 2 (4): 1–9. Paul, Gregory S. (2002). “Were Some Dinosaurs Also Neoflightless Birds?”. Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Johns Hopkins University Press. pp. 224–257. s. Paul, Gregory S. (2010). “Ornitholestes hermanni”. The Princeton Field Guide to Dinosaurs. Princeton University Press. pp. 123–124. Rauhut, Oliver W.M. (2003). “Operational Taxonomic Units”. The Interrelationships and Evolution of Basal Theropod Dinosaurs. Palaeontological Association. pp. 12–43. ScienceDaily. Meat-eating dinosaurs not so carnivorous after all. Senter, Phil (2006). “Forelimb function in Ornitholestes hermanni Osborn (Dinosauria, Theropoda)”. Palaeontology. 49 (5): 1029–1034. Topics similar to or like Pennaceous feather. Prominent feature exhibited by several bird and other dinosaur species on their heads. Distinct from features such as casques and cockscombs - sometimes erroneously referred to as "crests", which are keratinous and fleshy structures respectively. Wikipedia. Layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Wikipedia. Clade containing all animals with feathers. Defined based on an apomorphy, that is, a unique physical characteristic shared by one group and not found outside that group . Wikipedia. One of a set of feathers, called coverts , which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Wikipedia. Layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Wikipedia. One-of-a-Kind Dinosaur Specimen Discovered in China Offers View Into Dinosaur-Bird Evolution. Wulong bohaiensis. The skeleton described in the new paper is remarkably complete. The name means “Dancing Dragon” in Chinese and was named in part to reference its active pose. Credit: Ashley Poust. San Diego Natural History Museum paleontologist describes a dinosaur that is new to science, shows dinosaurs grew up differently from birds. A new species of feathered dinosaur has been discovered in China, and described by American and Chinese authors in the journal, The Anatomical Record . The one-of-a-kind specimen offers a window into what the earth was like 120 million years ago. The fossil preserves feathers and bones that provide new information about how dinosaurs grew and how they differed from birds. “The new dinosaur fits in with an incredible radiation of feathered, winged animals that are closely related to the origin of birds,” said Dr. Ashley Poust, who analyzed the specimen while he was a student at Montana State University and during his time as a Ph.D. student at University of California, Berkeley. Poust is now postdoctoral researcher at the San Diego Natural History Museum. Wulong artist’s rendering. Credit: Ashley Poust. “Studying specimens like this not only shows us the sometimes surprising paths that ancient life has taken, but also allows us to test ideas about how important bird characteristics, including flight, arose in the distant past.” Scientists named the dinosaur Wulong bohaiensis. Wulong is Chinese for “the dancing dragon” and references the position of the beautifully articulated specimen. About the Discovery. The specimen was found more than a decade ago by a farmer in China, in the fossil-rich Jehol Province, and since then has been housed in the collection of The Dalian Natural History Museum in Liaoning, a northeastern Chinese province bordering North Korea and the Yellow Sea. The skeletal bones were analyzed by Poust alongside his advisor, Dr. David Varricchio, from Montana State University while Poust was a student there. Wulong skull. Credit: Ashley Poust. Larger than a common crow and smaller than a raven, but with a long, bony tail which would have doubled its length, Wulong bohaiensis had a narrow face filled with sharp teeth. Its bones were thin and small, and the animal was covered with feathers, including a wing-like array on both its arms and legs and two long plumes at the end of its tail. This animal is one of the earliest relatives of Velociraptor , the famous dromaeosaurid theropod dinosaur that lived approximately 75 million years ago. Wulong’s closest well-known relative would have been Microraptor , a genus of small, four-winged paravian dinosaurs. The discovery is significant not only because it describes a dinosaur that is new to science, but also because it shows connection between birds and dinosaurs. “The specimen has feathers on its limbs and tail that we associate with adult birds, but it had other features that made us think it was a juvenile,” said Poust. To understand this contradiction, the scientists cut up several bones of the new dinosaur to examine under a microscope. This technique, called bone histology, is becoming a regular part of the paleontology toolbox, but it’s still sometimes difficult to convince museums to let a researcher remove part of a nice skeleton. “Thankfully, our coauthors at the Dalian Natural History Museum were really forward thinking and allowed us to apply these techniques, not only to Wulong , but also to another dinosaur, a close relative that looked more adult called Sinornithosaurus .” Wulong skeleton. Credit: Ashley Poust. The bones showed that the new dinosaur was a juvenile. This means that at least some dinosaurs were getting very mature looking feathers well before they were done growing. Birds grow up very fast and often don’t get their adult plumage until well after they are full sized. Showy feathers, especially those used for mating, are particularly delayed. And yet here was an immature dinosaur with two long feathers extending beyond the tip of the tail. “Either the young dinosaurs needed these tail feathers for some function we don’t know about, or they were growing their feathers really differently from most living birds,” explained Poust. An additional surprise came from the second dinosaur the scientists sampled; Sinornithosaurus wasn’t done growing either. The bone tissue was that of an actively growing animal and it lacked an External Fundamental System: a structure on the outside of the bone that vertebrates form when they’re full size. “Here was an animal that was large and had adult looking bones: we thought it was going to be mature, but histology proved that idea wrong. It was older than Wulong , but seems to have been still growing. Researchers need to be really careful about determining whether a specimen is adult or not. Until we learn a lot more, histology is really the most dependable way.” In spite of these cautions, Poust says there is a lot more to learn about dinosaurs. “We’re talking about animals that lived twice as long ago as T. rex , so it’s pretty amazing how well preserved they are. It’s really very exciting to see inside these animals for the first time.” About the Jehol Biota. The area in which the specimen was found is one of the richest fossil deposits in the world. The Jehol biota is known for the incredible variety of animals that were alive at the time. It is also one of the earliest bird-rich environments, where birds, bird-like dinosaurs, and pterosaurs all shared the same habitat. “There was a lot of flying, gliding, and flapping around these ancient lakes,” says Poust. “As we continue to discover more about the diversity of these small animals it becomes interesting how they all might have fit into the ecosystem.” Other important changes were happening at the same time in the Early Cretaceous, including the spread of flowering plants. “It was an alien world, but with some of the earliest feathers and earliest flowers, it would have been a pretty one.” Reference: “A new microraptorine theropod from the Jehol Biota and growth in early dromaeosaurids” by Ashley W. Poust, Chunling Gao, David J. Varricchio, Jianlin Wu and Fengjiao Zhang, 15 January 2020, The Anatomical Record . DOI: 10.1002/ar.24343. John A. Long (1) We all know about the birds and the bees, but what about the ancient placoderm fishes and the dinosaurs? The history of sex is as old as life itself —and as complicated and mysterious. In 2008, paleontologist John A. Long and a team of researchers revealed their discovery of a placoderm fish fossil, known as “the mother fish,” which at 380 million years old revealed the oldest vertebrate embryo—the earliest known example of internal fertilization. As a result, placoderms are now considered to be the first species to have had intimate sexual reproduction or sex as we know it—sort of. The Dawn of the Deed is Long's own story of what it's like to be a part of a discovery that rewrites evolutionary history as well as a rollicking guide to sex throughout the ages in the animal kingdom. It's natural history with a naughty wink. John A. Long is vice president of research and collections at the Natural History Museum of Los Angeles County. This discussion is free and open to the public. Those wishing to get books signed will be asked to purchase at least one copy of Dawn of the Deed from Vroman's, and one additional copy for every 3 books they bring from home. Save your Vroman's receipt; it will be checked when you enter the signing line. Location: Street: 695 E. Colorado Blvd City: Pasadena, Province: California Postal Code: 91101 Country: United States (added from IndieBound) … (more) More Evidence Birds Evolved From Dinosaurs / Researchers say long-extinct lizard didn't have feathers after all. One of the fiercest battles in science rages over the origin of modern birds: Were they descended from dinosaurs or some entirely different long- vanished species? Only a few months ago, opponents of the dinosaur theory proclaimed victory, insisting the skeleton of a foot-long lizard that lived 220 million years ago showed clear evidence of feathers and could glide or parachute from tree to tree, if not fly. It's as if that curious creature, known to scientists as Longisquama insignis, was actually an ancestor of our own domestic turkey, which will sacrifice itself, trussed and stuffed, on many American tables today. Now, however, a team of Canadian researchers has examined the evidence for feathers on the Longisquama fossils and contends they aren't feathers at all. The presumed feathers are nothing more than long, thick scales that left cup-like impressions in surrounding rock, the scientists, Robert R. Reisz of the University of Toronto and Hans-Dieter Sues of Toronto's Royal Ontario Museum, report in today's issue of the journal Nature. "Feathers are extremely paper-thin structures, but these have some depth to them, a real substantial three-dimensional nature. It's completely unlike bird feathers," Sues said. Their findings, Reisz and Sues write, mean that the fabled flying dinosaur Archaeopteryx -- which lived about 150 million years ago, 70 million years after Longisquama -- retains its rightful place as the earliest known bird. Fossils of the feathered Archaeopteryx, discovered in Germany in the 1840s, were one of the many clues that Charles Darwin considered in developing his first theories of evolution by "natural selection." Today, by far the majority of paleontologists consider that early bird as the first clear link in the dinosaur-to-bird lineage. In the Nature report, Reisz and Sues base their findings on only a single fossil sample of Longisquama, a fact that critics used to discredit the report. But in an interview yesterday Reisz said he and his colleague have examined all seven fossils, most recently at a Moscow conference only a month ago. All clearly bear the scale-like ridges tightly affixed to a membrane whose function is unknown, he said. The ragged fossils of the bizarre Longisquama were discovered 30 years ago in Russian Kyrgyzstan. But the dispute over them didn't arise until last summer when two scientists reported what appeared to be feathers on the creature. The scientists -- John A. Ruben of Oregon State University and Alan Feduccia of the University of North Carolina -- hailed the findings when they were published last July in the journal Science. "At the very least they prove that feathers did not evolve in dinosaurs," Ruben said. Ruben and Feduccia insist that while today's birds and the dinosaurs are probably related, they must be descended from an earlier and still unknown ancestral race of creatures. Ruben responded angrily to the Nature report. "That paper is nonsense, and it is completely unethical of the journal not to seek our reply," he said. "The fossil clearly has feathers, and it has a wishbone just as birds do. In fact, Longisquama is amazingly bird-like. Reisz and Sues are highly competent scientists, but their fossil is just a blob." Modern birds may well be "fairly closely related" to the dinosaurs, Ruben argued. Along with crocodiles and alligators they are all members of the ancient tribe known as archosaurs. "But there's no evidence at all that birds are descended from dinosaurs, and our belief is that all the archosaurs are descended from some distant ancestor for whom there's still a huge gap in the fossil record," he said. But Kevin Padian, a noted expert on dinosaur fossils at the University of California at Berkeley, takes issue with Ruben's statement. The lineage of dinosaurs to birds is backed by the strongest evidence, and the only convincing hypothesis, he said. Many different fossil species of feathered dinosaurs have been discovered in China by recent expeditions into the Gobi desert, Padian noted. In fact, he said, the Berkeley Museum of Paleontology will be mounting a striking exhibition in February of dinosaurs clearly covered with feathers.