How Did Pterodactyls Hit Earth

A dinosaur has an antorbital fenestra with an open hole hip socket. The definition differs from the term used informally because it helped understand how the dinosaur moved and how they were categorized as species. There are four general characteristics that dinosaurs have as a result of their synapomorphies which are permeated acetabulum, ball-shaped head on proximal femur, the Cnemial crest on the proximial tibia, and an ascending process on astragalus. These four dinosaur synapomorphies are related to vertical limb support.

This researcher proposes that the dinosaurs did not die of heat, in fact she thinks the opposite, that they froze to death instead. Both articles have the same idea about a meteorite hitting the earth yet there is no concrete evidence as to what caused the meteorite to strike and what it did when it got here.

The asteroid impact extinction theory began in 1980 with Luis and Walter Alvarez, a father and son team. They theorized that an asteroid struck the Earth at the close of the Cretaceous period, causing devastating effects and mass

It is difficult to envision that one of the greatest impact craters on Earth that measures up to 180km wide and 900m deep could just vanish just from sight. There have been many different dinosaur extinction theories offered in the recent decades. These range from poisonous plants to mass suicide by dinosaur herds. Although one concept as to how the dinosaurs became extinct has gained a wide acceptance since the 1980’s, involving a major earth impact by a meteor or comet (Icr.org, 2014). This horrific catastrophic event is thought to have extinguished up to two thirds of all animal and plant species, leaving behind a large crater found in Chicxulub, Mexico (LiveScience.com, 2014).

There was much speculation regarding the K/T boundary being caused by a meteorite. The impact of this event was believed to have led to extended volcanic activity periods that in turn further polluted the atmosphere. The impact of the K-T boundary happened to be attributed to the extinction of dinosaurs that might have been as a result of new diseases. The impact affected all living things including primates. The impact is believed to have drastically slowed primate evolution (Clyde, 2010).

While a theropod “beast-footed” carnivore includes the T. Rex, the ones that likely roamed Wrangel-St.Elias National Park were considerably smaller. The researchers found evidence of a single theropod that was likely a tiny 9 cm long and 7 cm wide due to an impression of the sinusoidal shape. Several ornithopod, medium and large plant-eating dinosaurs, was identified by blunt and rounded digit impressions which are usually 22 cm long and 26 wide. It was the first evidence that dinosaurs roamed this vast region.

pag). This seems to be the case because from the beginning, one creature has emerged into a more-developed one. It would be logical for humans, being the most evolved, to emerge into a greater creature with something of "superhero" qualities, one who would be invincible, and a species that would never perish. In comparison to this theory, anthropologist, John Hawks, states, "If in the far distant future, habitable planets beyond our solar system were colonized by Earth migrants, that could provide the necessary isolation for new human species to evolve" (Owen; n. pag). Although this seems highly likely to many, human evolution will cease to exist after this meteor hits Earth. Humans are a very vulnerable and fragile species, a species that can only handle so much. David Christian of Big History says that "humans would drown if we were left in water for too long and would freeze or asphyxiate if we were shot ten kilometers into the atmosphere" (Christian; n. pag). This is exactly why the theory of the destructive meteor is, in fact, accurate. If, or when, this meteor strikes, humans will face the same struggle in which the dinosaurs faced and they too will be classified extinct. The magnitude of this meteor will act like a self destruct button, destroying everything in its path, leaving no sign of further evolution

A crater, the Bedout crater, in Australia has been discovered. A bolide impact would have lead to mass death of marine and terrestrial organisms. The force of the impact could have released methane from stored organic matter and large earthquakes. These earthquakes would have triggered the volcanism in the Siberian traps, leading to the release of large amounts of CO2 and sulfur dioxide. These gases combined with methane previously released would have created a noxious atmosphere, combined with climate change that killed a large scale of life.

Pterosaurs flourished during the age of dinosaurs, more than 150 million years ago.  The earliest of their kinds are small flying reptiles. Yes, they do fly, with long tails and sturdy bodies and surprisingly, some were also extraordinarily large. However, roughly

This discovery is widely regarded as very good evidence that dinosaurs and birds share evolutionary traits, and disputes the assertion that they are unrelated; as made by those that support the ‘feathered’ Longisquama findings. As if this finding wasn’t enough, other feathered dinosaurs have been discovered in the same region of China. Protarchaeopteryx and Caudipteryx zoui lived about 125 and 145 million years

The word dinosaur was invented in 1842 by Richard Owen. Dinosaur comes from the Greek word “deinos” and “sauros” which translates to fearfully great lizard (“Learn about Dinosaurs”). Dinosaurs are always named in Greek and usually named after their unique fossils, where they 're found, it’s size or a person. Before a dinosaur can be officially named it must be approved by the International Commission on Zoological Nomenclature. It’s difficult to figure out how dinosaurs sounded, mated, behaved, what color/pattern they were and which ones are male or female. Paleontologists have however been able to discover that dinosaurs hatch from eggs, their bones have growth rings which can help figure out their age and that the larger dinosaurs lived for roughly 100 years and smaller ones for less. All dinosaurs evolved from other reptiles during the Triassic period. Dinosaurs are either herbivores or carnivores and are divided into two major groups. Bird hipped, Ornithischian, or lizard hipped, Saurischa. In the Saurischa hipped dinosaurs the pubis bone is down and to the front but in Ornithischian hipped it is point down and towards the tail (“Zoom Dinosaur”). The next step was to examine how dinosaurs behaved and their characteristics.

How exactly the asteroid damaged the Earth remains unclear, but the power released by such an impact is unquestionable. Effects possibly include reduced sunlight over a period of several months which possibly led to the decline or even total halt of primary production (via photosynthesis). One of the dominant signatures of the extinction at the KT boundary was the low activity of primary production, the possibility of reduced sunlight is high (Schulte et al. 2010) . Even if the primary production proved to be on a decline when this impact occurred, there is still some uncertainties as to where exactly the impact hit. This was why asymmetries in subsurface features of the Chicxulub crater were observed via geophysical methods were analyzed and it was calculated from estimates that the

Another theory, “psychoactive overdosing,” was proposed by UCLA psychiatrist Robert K. Siegel. He claims that angiosperms, or flowering plants, produced “an array of amino-acid-based alkaloids,” which dinosaurs would unconsciously eat and end up dying. This theory believes that dinosaurs did not have the livers nor the bitterness taste buds to notice and detoxify the psychoactive agents in the angiosperms. Last, but not least, a theory of a collision that came upon earth 65 million years ago. Father and son, Luis and Walter Alvarez, reconstructed a scenario that explained the death of dinosaurs on land, and proposed that a giant dust cloud darkened the earth; causing photosynthesis to discontinue, followed by a drastic temperature drop (pg. 452). Any hypothesis theory is a big contradiction. It is useful with all the advantages it has, yet it can be a disadvantage when an answer can never be found. While the first two theories of extraterrestrial catastrophe are captivating, the “disaster” theory seems more likely reasonable. The asteroid theory is the most developed answer based on the source of testable evidence of iridium – as it proves the dissimilarity of speculation and science when it was found

My outside source for questions 3 and 4 is a journal by Pat Shipman titled Fossils. This journal was published in The New Scientist Vol. 215, Issue 2876, p. 8-16.

This final blow would have sent earth into a nuclear winter. According to this theory, dust caused by the asteroid collision disrupted plant growth by blocking out the sunlight needed for photosynthesis for nearly a year. A chain reaction occurred as plants died off, so did the herbivores relying on the plants, and then the carnivores that relied on the herbivores. Around 75% of species became extinct, including dinosaurs, mammals, giant marine lizards, fish, birds, and insects. Meanwhile, seawater flooded around 40% of the world’s continents ("Mass Extinctions").