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Theropod dinosaur evolution into Birds

Theropod dinosaur evolution into Birds
Related:  DinosaursEvolution

Velociraptor - Predatory Behavior Smaller than other dromaeosaurids like Deinonychus and Achillobator, Velociraptor nevertheless shared many of the same anatomical features. It was a bipedal, feathered carnivore with a long tail and an enlarged sickle-shaped claw on each hindfoot, which is thought to have been used to tackle prey. Velociraptor can be distinguished from other dromaeosaurids by its long and low skull, with an upturned snout. Description V. mongoliensis compared in size to a human Velociraptor was a mid-sized dromaeosaurid, with adults measuring up to 2.07 m (6.8 ft) long, 0.5 m (1.6 ft) high at the hip, and weighing up to 15 kg (33 lb).[4] The skull, which grew up to 25 cm (9.8 in) long, was uniquely up-curved, concave on the upper surface and convex on the lower. Skeletal restoration As in other dromaeosaurs, Velociraptor tails had long bony projections (prezygapophyses) on the upper surfaces of the vertebrae, as well as ossified tendons underneath. Feathers History of discovery Provenance Paleoecology

The 6 Weirdest Ways Wild Animals Are Having to Adapt to Us Humanity's track record with animals has never been stellar. After centuries of ocean dumping, worldwide deforestation, domestication and overhunting, it's safe to say we've got a greasy, opposable thumb in every one of Mother Nature's pies. That's not to say that humanity's only effect on the animal kingdom is pure destruction; in fact, sometimes our ecological footprint looks more like a clown shoe. #6. Probably the only thing you know about parrots and cockatoos is that they can talk. After all, the pets that are raised among humans and learn (or learn to imitate) dozens of words sometimes either escape or are released into the wild. That's why people around Sydney, Melbourne and other big cities in Australia have found wild cockatoos using English phrases. Now imagine how crazy you'd think you were going if one day you were walking through the woods and you suddenly heard a disembodied bird voice tell you to eat a dick. Photos.com"Y'all bitches ain't shit AWWWK! #5. Photos.comProzac.

Elephant bird Description[edit] Size of Aepyornis maximus (centre, in purple) compared to a human, an ostrich (second from right, in maroon), and some non-avian theropoddinosaurs. Each gridline is one meter in height The elephant birds, which were giant ratites native to Madagascar, have been extinct since at least the 17th century. Species[edit] Four species are usually accepted in the genus Aepyornis today; A. hildebrandti, A. gracilis, A. medius and A. maximus,[7] but the validity of some is disputed, with numerous authors treating them all in just one species, A. maximus. Genus Aepyornis Genus Mullerornis Mullerornis betsilei (Milne-Edwards & Grandidier, 1894)[8]Mullerornis agilis (Milne-Edwards & Grandidier, 1894)[8]Mullerornis rudis (Milne-Edwards & Grandidier, 1894)[4][8][9]Flacourtia rudis (Andrews, 1894) Etymology[edit] Mullerornis agilis The ancient Malagasy name for the bird is vorompatra, meaning "bird of the Ampatres". Taxonomy and biogeography[edit] Aepyornis maximus restoration Biology[edit]

5 Bizarre Dinosaurs You Didn't Know Existed Admit it, everything you know about dinosaurs you learned from watching Jurassic Park. Or, possibly, you learned it while paying attention in school. That's never really been our scene, but to each their own. But no matter what route you took, there's a good chance your education was less than adequate. #5. Homestead.com Look, we're all adults here. Oh, you thought we were going to mention the shiny red shaft and matching set of testicles that's taken up permanent residence on this absurd dinosaur's stupid head? To be fair, the dinosaur in this picture is actually a toy. See? #4. Dinossaurosecia You know how people like to make fun of the T. rex because it has those stupid little arms that would be completely useless in a fistfight? What the hell are those things? #3. Critters.Pixel-Shack Similar to Edward Dildohands above, the Ouranosaurus seems perfectly designed or evolved for a life of suffering. No, seriously, we're asking. #2. Wikipedia #1. Dinopedia

Egg-laying beginning of the end for dinosaurs Their reproductive strategy spelled the beginning of the end: The fact that dinosaurs laid eggs put them at a considerable disadvantage compared to viviparous mammals. Together with colleagues from the Zoological Society of London, Daryl Codron and Marcus Clauss from the University of Zurich investigated and published why and how this ultimately led to the extinction of the dinosaurs in the journal Biology Letters. The dinosaur's egg and the tiny dino baby Weighing in at four tons, the mother animal was 2,500 times heavier than its newly hatched dinosaur baby. Many species occupy one niche each; one species occupies many niches In addition, new-born mammals occupy the same ecological niche as their parents: As they are fed with milk directly by the mother, they do not take any niche away from smaller species. Daryl Codron explains what this means for biodiversity: "The consensus among researchers is that animals of particular body sizes occupy particular niches.

Cetacean Palaeobiology The archaeocetes are a paraphyletic group of primitive cetaceans that include the earliest, terrestrial 'whales'. The group consists of six families: Pakicetidae, Ambulocetidae, Remingtonocetidae, Protocetidae, Basilosauridae and Dorudontidae, although some scientists include the latter two in one single family Basilosauridae. The graph below shows, how these families are related to each other. Cetacean Evolution In order to understand the biology of the archaeocetes, it is important to first consider what sort of terrestrial animals cetaceans originally evolved from. The relations of early whales (archaeocetes) to artiodactyls and the two extant groups, odontoceti and mysticeti. But in 1994, Dan Graur and Desmond Higgins, two scientists working on cetacean gene sequences dropped a bombshell. Astragali of the Eocene protocetids Rodhocetus balochistanensis (left) and Artiocetus clavis (right), as compared to that of the pronghorn Antilocapra americana (centre). Protocetidae (Stromer 1908)

Rare Dinosaur-Era Bird Wings Found Trapped in Amber Two tiny wings entombed in amber reveal that plumage (the layering, patterning, coloring, and arrangement of feathers) seen in birds today already existed in at least some of their predecessors nearly a hundred million years ago. A study of the mummified wings, published in the June 28 issue of Nature Communications and funded in part by the National Geographic Society's Expeditions Council, indicated they most likely belonged to enantiornithes , a group of avian dinosaurs that became extinct at the end of the Cretaceous period. (Read more about the evolution from dinosaurs to modern birds.) 'Mind-Blowingly Cool' While the fact that many, if not nearly all, dinosaurs were feathered has been generally accepted since the 1990s, our knowledge of prehistoric plumage until now has come from feather imprints in carbonized compression fossils and individual feathers fossilized in amber. Familiar Feathers A Bountiful Fossil Source in a Troubled Area Precious to Science, Impure to Consumers

When Did Dino's Sprout Wings? Dinosaurs still walk—and fly—among us: We call them birds. Most paleontologists think birds descended from a group of winged dinosaurs, and thus dinos never went completely extinct. But where did the wings come from? New discoveries from Canada suggest that both wings and feathers arose earlier in dinosaur evolution than previously thought, possibly to attract members of the opposite sex or to protect hatching baby dinos. Although many details of the origins of birds and winged flight are fiercely debated, researchers generally agree that birds belong to a group of dinosaurs called maniraptorans, some of which had feathers and wings and could probably fly.Microraptor, discovered in China, is a leading example of such a dino flyer. But the restriction of these discoveries to such a limited geographical area has left a gap in the fossil record, leaving paleontologists to wonder whether wings and feathers might have evolved in dinosaur groups older than the maniraptorans.

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