background preloader

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."Y'all bitches ain't shit AWWWK! #5. Photos.comProzac.

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)

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. 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

7 Animals That Are Evolving Right Before Our Eyes People who doubt evolution tend to have one main argument: "If evolution is true, why do we still see monkeys running around today, all chimp-like? Where are all the monkey-men I was promised?" Well, if you or someone you know refuses to believe that organisms change over time without proof on a monkey-man level, here are a buttload of animals in the middle of getting their evolve on. Elephants are Evolving to Lose Their Tusks (and Avoid Poachers) Here's a joke: What did the elephant say to the poacher? Getty"Stop! Sorry about that. GettyAnd ever since animal rights got involved, unemployment has shot up 300 percent. So elephants have decided to take matters into their own hands ... or trunks or weirdly rounded three-toed feet or whatever. By 2005, it was estimated that the tuskless population had risen to between 5 and 10 percent. GettyJust like your debilitating lisp after reading that out loud Which is incredible, because it's not like tusks are the elephant version of wisdom teeth.

Dinosaur True Colors Revealed for First Time by Feather Study Pigments have been found in fossil dinosaurs for the first time, a new study says. The discovery may prove once and for all that dinosaurs' hairlike filaments—sometimes called dino fuzz—are related to bird feathers, paleontologists announced today. (Pictures: Dinosaur True Colors Revealed by Feather Find.) The finding may also open up a new world of prehistoric color, illuminating the role of color in dinosaur behavior and allowing the first accurately colored dinosaur re-creations, according to the study team, led by Fucheng Zhang of China's Institute for Vertebrate Paleontology. The team identified fossilized melanosomes—pigment-bearing organelles—in the feathers and filament-like "protofeathers" of fossil birds and dinosaurs from northeastern China. Found in the feathers of living birds, the nano-size packets of pigment—a hundred melanosomes can fit across a human hair—were first reported in fossil bird feathers in 2008. End of Dinosaur-Bird Debate? A New World of Dinosaur Color

10 Animals You Won't Believe Are Closely Related Thanks to the know-it-all from second grade, we're all aware that dolphins and whales are mammals, not fish. But it's probably been a while since you've pondered just how incredibly, mind-blowingly weird it is that you and whales were the same animal more recently than whales and sharks. Or to put it in chart form, you and whales split up somewhere in the big tangle of bio diversity up top labeled "Age of Mammals" while whales and fish haven't been the same animals since way the hell down ... ... here where you see the word Selacchi. Courtesy of Getty Images." Turns out it's the same reason birds and bats both ended up flying around on wings: convergent evolution, the smarmy term for when completely unrelated species develop similar traits. Image By Glen Fergus What it looks like: You don't need your wife standing next to you screaming, "MOUSE! What it actually is: A tiny little mutant koala Image By Quartl Image By Cody PopeThe worst part? Image By Jagvar Via Wikipedia