Category: Dinosaur

Dinosaurs are a group of reptiles that dominated the land for over 140 million years (more than 160 million years in some parts of the world). They evolved in diverse shapes and sizes, from the fearsome giant Spinosaurus to the chicken-sized Microraptor, and were able to survive in a variety of ecosystems. As we all know, dinosaurs became extinct due to an asteroid that hit the earth 66 million years ago. There are many kinds of dinosaurs. The most famous and well-known dinosaur is called a “T Rex” short for Tyrannosaurus Rex. Tyrannosaurus Rex was one of the most ferocious predators to ever walk the Earth. With a massive body, sharp teeth, and jaws so powerful they could crush a car, this famous carnivore dominated the forested river valleys in western North America during the Late Cretaceous period, 68 million years ago. T Rex maintains a reputation for being the king of the dinosaurs.

Studying dinosaurs has played a key role in developing evolutionary theory and other scientific concepts, such as plate tectonics and biogeography. All of these pursuits arise as a result of humanity’s innate curiosity to investigate how our world works and where we fit within the natural world we see around us. Yet the dinosaurs remind us that life itself has helped to make our planet what it is. Whether scratching at the soil, trodding over the sand in search of greener pastures, or slipping on sand dunes, dinosaurs changed the shape of Earth.

As we know, it was the kind of cataclysm that we can scarcely imagine. A radioactive fireball seared everything for hundreds of miles in every direction and created tsunamis that sped halfway around the globe. But what if they hadn’t died out? Dinosaurs in the 21st Century, just like modern animals, would probably have reduced populations and face the threat of extinction.’ Big dinosaurs would perhaps only persist in protected reserves, such as national parks and wildlife refuges – modern-day equivalents of Jurassic Park.

Now, the real question is, can dinosaur DNA be recovered? The classic concept of dinosaur resurrection starts with a DNA-filled mosquito that has been preserved in amber for millions of years. But is this a scientific possibility or strictly resigned to fiction? When under specific circumstances blood does preserve, it doesn’t mean that scientists will find DNA in it. So even if a dinosaur’s blood was found inside an ancient insect, an opportunity to recreate the reptile from it isn’t guaranteed. An attempt to resurrect dinosaurs presents many caveats scientifically and ethically making things to put in zoos or amusement parks like Jurassic World likely isn’t the answer. So for now dinosaurs are probably going to remain safely in the past. But using genetic engineering to bring back extinct animals might be considered reasonable in some circumstances.

According to Black (2020), possible dinosaur DNA has been found talking about discoveries raising the possibility of exploring dinosaur genetics. The tiny fossil is unassuming, as dinosaur remains to go. It is not as big as an Apatosaurus femur or as impressive as a Tyrannosaurus jaw. The object is just a scant shard of cartilage from the skull of a baby hadrosaur called Hypacrosaurus that perished more than 70 million years ago. But it may contain something never before seen from the depths of the Mesozoic era: degraded remnants of dinosaur DNA.

Genetic material is not supposed to last over such periods—not by a long shot. DNA begins to decay at death. Findings from a 2012 study on moa bones show an organism’s genetic material deteriorates at such a rate that it halves itself every 521 years. This speed would mean paleontologists can only hope to recover recognizable DNA sequences from creatures that lived and died within the past 6.8 million years—far short of even the last nonavian dinosaurs.

Recovering genetic material of such antiquity would be a major development. Working on more recently extinct creatures—such as mammoths and giant ground sloths. Paleontologists have been able to revise family trees, explore the interrelatedness of species and even gain some insights into biological features such as variations in coloration. DNA from nonavian dinosaurs would add a wealth of new information about the biology of the “terrible lizards.”

Yet first, paleontologists need to confirm that these possible genetic traces are the real thing. Such potential tatters of ancient DNA are not exactly Jurassic Park–quality. At best, their biological makers seem to be degraded remnants of genes that cannot be read—broken-down components rather than intact parts of a sequence. Still, these potential tatters of ancient DNA would be far older (by millions of years) than the next closest trace of degraded genetic material in the fossil record. At the moment, molecular paleontology is controversial. Nevertheless, molecular paleobiology is developing standards of evidence and protocols as it continues to search for clues held inside ancient bones.

Even if the proposed dinosaur organics turn out to be false, the effort could still yield unexpected benefits. Bacterial communities are thought to be involved in the preservation of bones and their replacement with minerals, thus helping dinosaur remains become fossils. Future studies about ancient DNA from past microbial communities that used to live inside the dinosaur bones could shed more light on the roles of microorganisms in the fossilization and preservation of bones through geological time.

As reported by Peek (2021), in the two centuries since the first dinosaur bones were identified in England, nearly 11,000 dinosaur fossils have been unearthed worldwide, two-thirds of them in North America and Europe. Most of the finds have been made in the home countries of paleontologists; the ease of local fieldwork has led to a concentration of discoveries in well-traveled areas. Widening the scope depends on building local expertise—a tricky task for a fair niche (and not particularly lucrative) field.

Coinciding with Black (2020), even in a year when fossil explorations have been curtailed because of the Covid-19 pandemic, paleontologists have dug deep to describe dozens of new species and unlock new series about our favorite prehistoric creatures.

Dinosaurs are often celebrated for being big, fierce, and tough. The truth, however, is that they suffered from many of the same injuries and maladies that humans do. The animal, a horned dinosaur known to experts as Centrosaurus, probably coped with declining health before its eventual death in a coastal flood that caught its herd off-guard.

If dinosaurs “ruled the Earth” for millions of years, why were they hit so hard by the mass extinction of 66 million years ago? Paleontologists have been puzzling over this question for decades, and, some have suggested, dinosaurs might have already been dying back by the time that the asteroid struck. The researchers looked at different evolutionary trees for what dinosaurs were around during the end of the Cretaceous to track whether dinosaurs were dying out, thriving, or staying the same. Dinosaurs seemed perfectly capable of evolving new species.

In addition to this, the researcher became interested in this one specific dinosaur named Velociraptor. Velociraptors are said to be a genus of dromaeosaurid theropod dinosaurs that lived approximately 75 to 71 million years ago during the latter part of the Cretaceous Period. Smaller than other dromaeosaurids like Deinonychus and Achillobator, Velociraptor nevertheless shared many of the same anatomical features. Pterosaurs are distantly related to dinosaurs, being members of the clade Ornithodira.

The other groups mentioned are, like dinosaurs and pterosaurs, members of Sauropsida, except Dimetrodon. Modern birds inhabit most available habitats, from terrestrial to marine, and there is evidence that some non-avian dinosaurs could fly or at least glide, and others, such as spinosaurids, had semiaquatic habits.

Therefore, the answer to the question “Can dinosaur DNA be recovered?” is yes. This speed would mean paleontologists can only hope to recover recognizable DNA sequences from creatures that lived and died within the past 6.8 million years—far short of even the last nonavian dinosaurs. But then there is the Hypacrosaurus cartilage. With the help of genetics, paleontologists, and scientists we have hope of bringing the dinosaurs back. But is this a scientific possibility or strictly resigned to fiction? When under specific circumstances blood does preserve, it doesn’t mean that scientists will find DNA in it. So even if a dinosaur’s blood was found inside an ancient insect, an opportunity to recreate the reptile from it isn’t guaranteed. An attempt to resurrect dinosaurs’ presents many caveats scientifically and ethically making things to put in zoos or amusement parks like Jurassic World likely isn’t the answer. So for now dinosaurs are probably going to remain safely in the past. But using genetic engineering to bring back extinct animals might be considered reasonable in some circumstances.

References

1. Rae, S., Hendry, L., What are dinosaurs, https:www.nhm.ac.ukdiscoverwhat-are-dinosaurs.html
2. American Museum of Natural History, July 2012, How do dinosaurs benefit humanity, https:www.amnh.orgexplorevideosdinosaurs-and-fossilshow-does-studying-dinosaurs-benefit-humanity
3. Black, R., July 2016, Dinosaurs Literally Reshaped the Planet, https:www.smithsonianmag.comscience-naturedinosaurs-literally-reshaped-planet-180959814
4. Pickrell, J., September 2017, What if dinosaurs hadn’t died out? https:www.bbc.comfuturearticle20170918-what-if-the-dinosaurs-hadnt-died-out
5. Pickrell, J., What if the dinosaurs had survived? https:www.sciencefocus.comnaturewhat-if-the-dinosaurs-had-survived
6. Osterloff, E., Could scientists bring dinosaurs back to life, https:www.nhm.ac.ukdiscovercould-scientists-bring-dinosaurs-back.html
7. Black, R., April 2017, Possible Dinosaur DNA Has Been Found, https:www.scientificamerican.comarticlepossible-dinosaur-dna-has-been-found
8. Peek, K., February 2021, Dinosaur Discoveries Are Booming, https:www.scientificamerican.comarticledinosaur-discoveries-are-booming

Dinosaurs first appeared in the latter half of the middle Triassic 230-240 million years ago; they were originally bipedal carnivores, and quite small relative to the colossal dinosaurs that proceeded them. These primitive dinosaurs rapidly evolved into the two major clades we know of today; Ornithischia and Saurischia, Saurischia being comprised of both Sauropoda and Therapoda. Saurischia makes up all carnivorous dinosaurs and birds, as well as the long-necked herbivorous sauropods while ornithischia is classified as any non-sauropoda herbivorous dinosaur such as the armoured dinosaurs (Ankylosauria). Dinosaurs truly “conquered” Earth, spanning across a giant 165-million-year period they dominated and spread to every inch of the land and skies; but how?

It’s believed that the success of dinosaurs was propelled by the misfortune of prior life, the Permian-Triassic extinction event, also known as the “great dying” resulted in the extinction of “90% of the sea creatures and 80% of those on land during this period about 250 million years ago” (Spears, 2004). The commonly agreed upon theory for the cause of the Great Dying is that over a period of thousands of years constant volcanic eruptions flooded the atmosphere with particulates, significantly altering the climate and depleting oxygen levels; essentially suffocating all life, however some scientists believe it was caused by a meteor that was travelling so quickly it vaporised upon impact, altering the planet’s climate to a point where the fallout was still being seen millions of years later (Spears, 2004).

Regardless of the exact cause, this huge loss of life meant that there were vast amounts of space and thus great ecological opportunity, giving rise to the dinosaurs. With all the big hunters extinct, dinosaurs burst out of South America and began occupying different habitats and climates; encouraging them to fill niches and speciate. As well as this, as the success and population of dinosaurs continued to exponentially climb, movement became more restricted and competition increased, this put further selection pressures onto dinosaurs to occupy small ecological niches and become more specialised to avoid competition with other species. The specialisation of dinosaurs was one of their greatest attributes, but it was also their greatest weakness, specialisation in dinosaurs was a double edged sword in that it allowed for every habitat to be potentially occupied by a species of dinosaur, but also meant that they were incredibly vulnerable to environmental change.

While in the recent past many scientists believed that after the Great Dying dinosaurs simply overwhelmed their competitors and spread throughout the corners of Earth, many believing “dinosaurs as very successful animals that outcompeted other species wherever they went” (Reisz, cited in How dinosaurs conquered the world! – ProQuest, 2010) a recent study suggests dinosaurs were in fact “opportunistic creatures” (Reisz, cited in How dinosaurs conquered the world! – ProQuest, 2010) that only moved into areas such as North America following the Triassic-Jurassic mass extinction event 201 million years ago; this was theorized from Sarahsaurus fossils which suggest that Sarahsaurus and fellow sauropods migrated “in three distinct waves and only after the extinction event, what habitats were relatively free to occupy” (Boswell, 2010). Overall, this evidence suggests with a moderately firm basis that early dinosaurs functioned at least partly on an opportunistic basis and chose to expand outward when mass extinction events made ecological gaps that they could fill.

Additionally, another problematic competitor to the dinosaurs and their spread was the pseudosuchians. Prior to the Triassic-Jurassic extinction event they were significantly bigger and more successful than fellow dinosaurs of the time, however after the Triassic-Jurassic extinction occurred, they were almost completely wiped out, opening up a gap for dinosaurs to take on the role as the dominant reptiles. Although it isn’t completely known why dinosaurs survived the Triassic-Jurassic extinction, it’s theorized that their breathing system; the same as that of birds today made the saurischian dinosaurs far better equipped than mammals and “old” reptiles such as pseudosuchians to deal with intense environmental conditions in which the oxygen was half of modern day’s 21% (Ultra-low Oxygen could have triggered Die-offs, 2003). Based upon this information it’s somewhat clear that dinosaurs replaced pseudosuchians as the most common and widespread animal, and based on little evidence it’s inferable that a reason they may have survived the Triassic-Jurassic extinction is the efficiency of their bird-like lungs, but ultimately this theory is uncertain.

As the Jurassic period began and dinosaurs expanded due to few competitors, they began exploding in size, one reason which allowed this was the presence of pneumatized bones; these are bones which have hollow spaces within them, allowing them to be significantly lighter than usual whilst retaining a lot of strength; ultimately meaning they could be larger than typically possible whilst resisting the effects gravity would usually have on an animal of that size. Moreover, as touched on before many dinosaurs had a similar breathing system to modern day birds, besides lungs they also had air sacks that would protrude spaces in their bones and allow for highly effective breathing (How did dinosaurs get so big?, 2009), and more so than other competition of the time. Evidently dinosaurs being bigger reduced the number of animals that could compete and prey on them, which practically ensured the fact that they would conquer Earth.

Despite dinosaurs being so seemingly invincible, they were completely wiped out by the end-Cretaceous mass extinction that ended their reign 66 million years ago. An asteroid estimated 6 miles in diameter hit earth and left a crater over 180km across (Hartmann, n.d.). During the impact a colossal amount of kinetic energy would have been created and millions of tonnes of debris would have been thrust into the atmosphere; likely leading to an Earth “shrouded in a dust layer that blocked sunlight for several weeks or months” (Hartmann, n.d.). Additionally, debris would have eventually fallen back down to the troposphere, resulting in a bombardment of fireballs thousands of degrees hot. The energy released from these alone was probably enough to kill the majority of flora and fauna on the surface from heat stress. Organisms with no where to hide either and or due to their size and lifestyle like the dinosaurs “might have been decimated in hours or weeks” (Hartmann, n.d.), however organisms who lived underground had a far greater chance of surviving, which is likely why mammals proceeded dinosaurs after their extinction.

Following the primary effects of the asteroid, it’s likely an impact winter would have followed; this is the theorised result of an asteroid impact where millions of tonnes of debris being thrown into the atmosphere results in skies blanketed in ash, preventing the sun from reaching the surface and rapidly lowering temperatures. As touched on before, dinosaurs were a highly specialised species and were extremely vulnerable to change in an environment, therefore the adaptions required for them to survive the sudden change in climate the Chicxulub asteroid caused would have been all but impossible.

In conclusion, it’s clear the dinosaurs 180-million-year reign was both begun and ended by mass extinction events. Initially being on the side better adapted to survive in an environment wiped clean of competition following the Permian-Triassic extinction they thrived and spread throughout the world, taking advantage of the ability to fill various niches and specialise themselves to specific habitats. This effort was greatly supported by the advantages of their physiology such as pneumatized bones and an effective breathing system, which allowed them to grow to unimaginable sizes whilst also potentially being a factor in why they overcame the Triassic-Jurassic mass extinction and outlasted the majority of the pseudosuchians and other competitors. In the end the dinosaurs fell victim to their most powerful attribute of specialisation being unable to adapt in a post-asteroid world where the former ecological niches they belonged to no longer existed.

Dinosaurs ruled the land, the ocean, and the sky for about 165 million years. Rex Tyrannosaurus hunts its prey with 50 to 60 banana-sized teeth. The 55-foot dragon from nose to tail frightened the ocean and ate everything they could catch. But 66 million years ago, the world’s climate changed dramatically. Suddenly, the earth became colder and darker. All dinosaurs-except for the ancestors of modern birds-and three-quarters of the creatures on Earth are extinct. To this day, scientists are still arguing what caused this sudden change.

The main theories include asteroid impacts and volcano eruptions. The two main theories start with a metal called iridium. This element only does exist in Earth’s liquid core and space rocks such as asteroids. Among the rocks below the Earth’s oceans and continents is a thin layer of iridium, which geologists call the K-T boundary, or where in geological records they saw evidence of mass extinction of dinosaurs. After the discovery of this layer, scientists speculate that about 66 million years ago, a huge meteor six miles across hit the earth. The effect would be the equivalent of 10 billion nuclear bombs, which would throw tons of iridium powder and other debris into the air, blocking out sunlight for years.

Researchers have discovered a huge crater on Mexico’s Yucatan peninsula that may have caused the most damage in the right place. Rocks in the area could be particularly rich in carbon dioxide, sulfur or hydrocarbons, all of which could be released, and the air could affect and cause rapid climate change. Scientists have also found some other strange clues in ancient formations: shocking quartz, which looks like huge shock waves rearranged crystal rocks; soot indicates wildfire spread; and glassy spheres like cooled molten rocks. Not everyone believes that a huge fireball marks the end of the dinosaurs. Some say that iridium layers and strange rock clues may also be related to volcanic activity, not only asteroid impacts. During the last 40 million years of dinosaur rule, volcanoes erupted.

In today’s western India, huge volcanic cones spew lava from the mantle, dust and volcanic ash. After millions of years of volcanic eruption, scientists reasoned that there could be enough debris in the air to block the sun. The volcano may also attract iridium from the depths of the earth, forming the thin layer we see in the crust today. Some scientists believe that the impact of the volcanic eruption on the climate is not enough to kill all dinosaurs. Others say the truth may be a combination of these two theories. Asteroids may even worsen the volcanic eruption, giving the dinosaurs a double geological blow. Other scientists believe that dinosaurs began to become extinct before a catastrophic event ended. Whether it’s an asteroid or a volcano, we all know that the entire Earth has undergone sudden and drastic changes. When the darkness receded, surviving mammals, reptiles and birds took over the earth. This story has been updated to reflect the fact that the theoretical impact of asteroid collisions is along the route of 10 billion nuclear bombs, rather than the 10 nuclear bombs previously mentioned. We regret this mistake.

Over the years, earth has gone through several changes. Before humans roamed the earth, there were dinosaurs. They lived here over 66 million years ago. Dinosaurs lived and moved through land, air, and water. Many Dinosaurs lived during different eras of earth’s time. They once lived and hunted where we now stand. We are constantly finding fossils of known species and entirely new ones. Misconception about them are still being disproven. We are constantly learning new things about them. This paper will talk about three chosen dinosaurs. Then look into their physical feature, habitat, hunting skills, and life expectancies. Along with examining their eras of time.

One of the most feared dinosaur was the Tyrannosaurus rex which is also known as the T-rex. They were the apex predator of their time. Tyrannosaurus rexes were feared because of their size and food preference. According to the National Geographic (2017), a Tyrannosaurus rex was about 40 feet long and about 15 to 20 feet tall. They had thick massive skulls and long jaws for massive bites. Due to their shear size, T-rex where not very fast. They could only walk about 3 to 6 miles per hour. Their elongated, serrated teeth were made to pierce and rip flesh from their prey. While eating a T-rex would swallow chunks whole unlike other animals. The American Museum of Natural History (AMNH) says that a T-rex could eat about 500 pounds of meat in one bite which crushed and broke bones while eating. Their diet mostly consisted of herbivorous which included Triceratops and Edmontosaurus. They were estimated to weight 11,000 to 15,000 pounds.

Arms were very short and stubbly which contained only two fingers (Switek, 2013). Scientist do not know the full functionality of their small are due to them not being able to reach their mouths. Legs had strong thighs with a powerful tail thus counterbalancing its large head (Castro,2017). The T-rex life expectancy was only 28 years old. They reached their adult height while they’re in their teenage year. Tyrannosaurus rex lived during the late Cretaceous period. Which was about 90 to 66 million years ago. They went extinct about 65 million years ago during the Cretaceous Tertiary mass extension (National Geographic). Tyrannosaurus rex was first discovered in 1902. Most T-rex fossils were found in the Northwest of the United States such as Montana and South Dakota. Some fossils were also found in Alberta, Canada (AMNH). The meaning of the Tyrannosaurus rex name was the tyrant lizard king.

Another predator from the late Cretaceous period was an Oviraptor. Oviraptors were small, light built with slender limbs, grasping hands with distinctive skulls (Smith, 2005). The grew to the length of 6 feet long. Similar to T-rexes, they walked on two feet. Their arms were long and slender with only three clawed fingers (Britannica, 2018). The arms were well suited for grasping, ripping and tearing their food. Their skulls were very short and deep. They had noticeable cranial crest containing a large nasal cavity which the function is unknown (Smith, 2005). Mouths were peak shaped. Their jaws were well muscled and adept for crushing. Oviraptors were omnivorous which means they ate plants and meat. Their diets mostly consisted of hard fruits, clams and shellfish. Their name originated by the terms egg thief because fossils were found near a nest of eggs believed to be of another dinosaur. For many year, people believed that Oviraptor consumed eggs. Upon further examination it was noticed that it was the Oviraptor’s nest. Just like birds, Oviraptors brood over their nest. Fossils of Oviraptors were discovered in Eastern Asia and North America. This was due to the supercontinent Laurasia being connected. Their habitats may have consisted of hot, windblown sands of their region.

Archaeopteryx have become essential in understanding evolution. Archaeopteryx had well developed wings with feathers which allowed them to fly. Their wings had three talons to help them glide through the air. Three of their fingers bore claws and each moved independently which help them grasp prey or trees (“Archaeopteryx: An Early Bird”, 1993). They feet also bore a hyperextensible second toe which also known as a killing claw. They weight about 1.8 to 2.2 pound about the same size of a raven.

According to Joseph Castro, Archaeopteryx feather on their legs, wings and body but lacked feathering on their neck and head. Their shoulder girdle limited it’s flapping abilities due to this they could not fly very far or long. The feathers of the wings and tail added an additional aerodynamic function. Wings were rounded at the ends and their tails we up to 20 inches long. They had a flat sternum, with a long bony tail and belly ribs. Their feathers, wing, wishbones and reduced fingers are similar characteristics of a bird but not of modern birds. Along with the thin hollow bones and air sacs within their backbones. It was believed that they were the first birds which was later disproven. Archaeopteryx where small carnivorous with their cone-like teeth within their upper jaws helps them rip and shred their meal. Their diet consisted of small reptiles, amphibians, mammals and insects. Castro says, “It likely seized small prey with just its jaws and may have used its claws to help pin larger prey.” Archaeopteryx were first discovered in 1860 near Solnhofen, Germany. They lived around 150 million years ago during the late Jurassic period. Around this time, Europe was closer to the equator with its climate being fairly warm and dry.

The earth has gone through different phases. Each phases was a time period for different dinosaur. The Archaeopteryxes time was before the Tyrannosaurs rexes and the Oviraptors. Its time period was the Late Jurassic. The Jurassic time period is considered the second period of the Mesozoic era. It extended from 200 million to 145 million years ago. The Jurassic was considered to be “ The Age of the Dinosaurs”. During this time, Pangaea the supercontinent split apart but still very close together. With Pangea splitting it cases the earth to warm which allowed a perfect environment for dinosaurs to dominate. The Marine life was highly diverse. The plant life had evolved from low-growing mosses known as Bryophytes (“Jurassic Period Facts”, 2013). This means that some plants moved from living in the ocean to living on land. Plants then developed a new method for reproduction. The wind was used to transport all exposed seeds to get a greater genetic combination during reproduction (Tang, 2019). The combinations helps the plants have a better survival with their new environment.

Another Mesozoic period was the Cretaceous. The Tyrannosaurs rex and the Oviraptors where a part of the Late Cretaceous. The Cretaceous period lasted 145 million to 66 million years ago. Most rocks from this time period were mostly made of chalk which they provided clear details of the time period. During this time Pangea had already split but the continents were still moving. The continents then created Gondwana within the south and Laurasia in the north. As the continents moved apart ocean levels began to rise higher. Land structure we know today were underwater. Toward the end of the Cretaceous Gondwana and Laurasia also split apart.

The plants during this time gained the ability to produce flowers. According to Mary Bagley (2016), it was thought that pollinating insects evolved during the same time that plants did. When in reality these insects we well established before the first flower. In the beginning of this period temperature was lower. During the middle of the period, temperatures reached its maximum which meant that it was much warmer than it is today. Hansen and Koch (2018) says that with floral evidence suggested that the climate was that of tropical to subtropical conditions that extended to the poles. The cretaceous period was biologically significate because early life form made the transition to be more advanced and diverse. Many modern animals began making their debut during this time.

Toward the end of the Cretaceous period, there was a mass extension. The dinosaurs perished but plant life was less affected (Hansen and Koch, 2018). This was the largest mass extension in earth’s history about 80% of animals disappeared. There are several theories that explain what might has caused the mass extension. Many believe the theory of an asteroid impacting earth caused the extension. When the asteroid impacted it sent pieces of debris into the atmosphere which plunged the earth into darkness which ceased plant growth (Hansen and Koch, 2018). The impact also triggered shockwaves, massive tsunamis and when debris fell back to earth from the atmosphere it caused forest fire (Bagley, 2016).

Before humans roamed the earth, there were dinosaurs. Dinosaurs lived and moved through land, air, and water. Many Dinosaurs lived during different eras of earth’s time. We are constantly finding fossils of known species and entirely new ones. Along with learning new things about them. One of the most feared dinosaur was the Tyrannosaurus rex which is also known as the T-rex. They were the apex predator of their time. Tyrannosaurus rexes were feared because of their size and food preference. Their diet mostly consisted of herbivorous which included Triceratops and Edmontosaurus. Tyrannosaurus rex lived during the late Cretaceous period. Which was about 90 to 66 million years ago. Tyrannosaurus rex was first discovered in 1902. Another predator from the late Cretaceous period was an Oviraptor. Oviraptors were omnivorous which means they ate plants and meat. Their diets mostly consisted of hard fruits, clams and shellfish. Their name originated by the terms egg thief because fossils were found near a nest of eggs believed to be of another dinosaur when in reality it was their own nest. Fossils of Oviraptors were discovered in Eastern Asia and North America. This was due to the supercontinent Laurasia being connected. Their habitats may have consisted of hot, windblown sands of their region. Archaeopteryx have become essential in understanding evolution. It was believed that they were the first birds which was later disproven. Their diet consisted of small reptiles, amphibians, mammals and insects.

Archaeopteryx were first discovered in 1860 near Solnhofen, Germany. They lived around 150 million years ago during the late Jurassic period. Around this time, Europe was closer to the equator with its climate being fairly warm and dry. The earth has gone through different phases. Each phases was a time period for different dinosaur. The Jurassic time period is considered the second period of the Mesozoic era. It extended from 200 million to 145 million years ago. The Jurassic was considered to be “ The Age of the Dinosaurs”. The Marine life was highly diverse. Another Mesozoic period was the Cretaceous.

The Cretaceous period lasted 145 million to 66 million years ago. The plants during this time gained the ability to produce flowers. During the middle of the period, temperatures reached its maximum which meant that it was much warmer than it is today. The cretaceous period was biologically significate because early life form made the transition to be more advanced and diverse. Many modern animals began making their debut during this time. Toward the end of the Cretaceous period, there was a mass extension. Many believe the theory of an asteroid impacting earth caused the extension. These are just some facts that we have learned about dinosaurs and their time period. Everyday scientists are making new discoveries. We are continuedly finding fossils which shows us new information. So, we are constantly learning new things.

The Cretaceous- Paleogene boundary is evidence shown in the rock layers of a mass extinction that occurred approximately 65 million years ago. From the evidence left behind of this event, leave scientists debating theories on how this sudden and significant event in Earth’s history took place, and why it led to the extinction of so many species. From the 5 massive extinctions identified in Earth’s history, the extinction of the dinosaurs of dinosaurs was by far the deadly.

The most evidential theory of why this occurred, was an asteroid larger than Mt Everest, hitting where know today to be the Chicxulub, Gulf of Mexico. The string of events that followed the asteroid’s impact is what lead to the Cretaceous-Paleogene extinction event. It is the leading theory that the extinction of the dinosaurs, also known as the Cretaceous-Paleogene extinction event took place due to an asteroid hitting the earth 65 million years ago. This large mass was supposedly larger than today’s Mt Everest. This impact released a huge amount of energy, vaporising the matter nearby, with rippling shockwaves.

The dinosaurs near the impact were destroyed some buried alive. It is quite believable that a meteorite could hit the Earth at some point since its formation 4.6 billion years ago, but some struggle to understand how such an impact in one area of the planet could wipe out majority of life. It wasn’t so much the initial impact that killed the dinosaurs, but the series of domino effects that followed, which caused ecosystems globally to crumble. The impact of the asteroid caused tsunamis into the coastlines around Mexico, and started fires on land which was carried by winds. Matter was released into the atmosphere, some travelling to the moon and back into space, while some was pulled back into orbit, resulting in a devastating meteor shower all around the planet. The debris re entering the atmosphere was travelling at intense speeds and reaching extreme temperatures. This heat dries out vegetation, leading to firestorms. These meteorites and debris scatter and rain down around the planet for at least 4 days. We know this because of discovered rock identified from Mexico all around the world. A cloud of ash and soot blankets the sky, which resulted in a ‘endless night’, causing cold periods, killing organisms relying on sunlight to photosynthesize. With vegetation dying worldwide, herbivores died of starvation. Domino effects continue as the food chain collapses. With limited herbivores, carnivores suffer also.

The largests carnivores died of first, as they require a larger source of food. This extended period of darkness affected sea life also, and took 3 million years for oceans to recover. 10,000 billion tonnes of carbon was released from the fires. To put in perspective, that is 3000 years worth of our modern carbon release, so you can imagine the significant consequences this would have on the environment. So much so, leading into the various cycles of climate changes over next eras. A lot of the dust cloud was distributed by the winds globally to create the boundary, the boundary has since been affected in the past 65 million years. Tectonic activity such as earthquakes and volcanoes have shifted the boundary, as well as erosion and weathering. We have significant evidence of these events occuring, a combination of stratigraphic evidence and radiometric dating. This geological event is significant because it is one of this main 5 mass extinction events identified in Earth’s history. These events are due to change in environment and help geologists identify time periods and eras. Each time period or era ends in a climate/ weather, landscape change, resulting in a loss of biodiversity.

A new time period begins when fauna begin to adapt to the new environment and new ecosystems are redeveloped. There are 3 main geological eras in earth history; the Paleozoic, Mesozoic, and Cenozoic, complete with sub periods in each. As seen in the diagram, this mass extinction is called the cretaceous-paleogene extinction event because it was the event that ended the cretaceous period and began the Paleogene period (at ‘K-T’ boundary seen at this point in the diagram) and big enough to also begin the Cenozoic Era. The K-T boundary, now referred to the the KPg boundary (K short for Cenozoic, and Pg short for Paleogene), is a very significant piece of evidence of this extinction event. The Kpg boundary is useful because we can use stratigraphy to determine relative terms how long ago the event happened. Other sources of evidence such as fossils and their placement, radiometric dating help determine an accurate estimate about when and what happened during this period. Because both absolute and relative dating need to be used in conjunction to figure out an timeline of earth’s history. To analyse stratigraphic evidence, rocks are organised into several classifications. Rock classifications allow geologists to identify patterns and explanations for what has happened. There are 3 main categories of rock, with varying characteristics: Igneous rock is holey and less dense. This is because the igneous rocks are a product of volcanic activity, and the molten rock cooled with gas bubbles.

Metamorphic rock (root word meaning changing/ transforming) is formed from pressure and heat. Sedimentary rocks are made of sediments compressed together and is a good layer of rock to show fossils (essential evidence of time periods) We know by the category of a rock, what type of geological events it had to go through to end up this way. The colour of a rock can tell us what the rock is made of. A dark colour could mean Basalt rock, and little lighter than Basalt would be Andesite rock, while a paler beige/ white rock could be Rhyolite rock.

The classifications of these 3 types of rock is because of the different amounts magnesium and iron and how much silica. Generally the more silica is the lighter the rock will appear. We can also discover things from rocks by looking at their composition, for example: the crystal size. We can often see crystals in metamorphic rocks and sometimes even igneous rocks. If the crystals are small, we know the rock cooled quickly( example of obsidian – when water meets lava. If there are larger crystals we know the rock cooled down over a long period of time – days up to years (ie Copper sulfate homemade crystals – takes about 2 weeks). There are alot of inferences you can make by studying rocks. Stratigraphy is significant because it shows geologists a history of events by looking at the rock layers. This method works based on the law of superposition, meaning the old rocks are further below, and the newest rocks are closer to the surface. The benefits of using stratigraphy is by looking at the rock layers we know in what order events happened.

The drawbacks of using only stratigraphy is there are no numeric ages, we only know in what order events happened. A numeric piece of evidence that helps us understand when and how this extinction is by using radiometric dating. To understand how this works we need to look at the chemical composition of fossil or rock samples. Radiometric dating is used to analyse the decay of samples, by figuring out how many half lifes it has gone through. There are several types of radiometric dating. Selecting the most appropriate method for the senorio and/or using several methods of radiometric dating to accurately estimate the age of something. Radiometric dating can and has been used to find the ages of both natural and man-made materials. This diagram shows example of mass-energy theory and equation E=mc^2 is relevant when looking at nuclear fission event. Nuclear fission happens when the nucleus is too large and unstable causing it to split. Breaking down into smaller nuclei.

The Electrostatic force is larger than the strong nuclear force. In other words, the strong nuclear force (attractive) is overcome by the (repulsive) electrostatic force, causing the nucleus to split therefore releasing energy. The original mass is not equal to the total masses after the fission event due to energy being released. The number of nucleons will be conserved but the mass will be different. Mass-energy equivalence means mass is just concentrated energy, that can be released and transferred. This concept is important when understanding how nuclear physics is applied when trying to use radiometric dating to find the age of objects. Radioactive decay means that the nuclei of some isotopes are unstable and can split up or ‘decay’ and release radiation.

Binding energy is the amount of energy that is needs to split nucleons from its nucleus, and mass defect is a nucleus’ mass minus the total mass of the nucleons. Binding energy and mass defect explain why energy is needed to split nucleons from its nucleus. Binding energy and and the mass defect are equal to each other.

Binding energy = Mass defect x C^2 E = mc^2

Energy is mass, and if the nucleons have a greater mass due to their increase in energy, the nucleus becomes too large causing fission to occur. Main methods of radiometric dating are carbon dating, Potassium-argon dating, and Uranium-Lead dating.

The equation for radioactive decay is D = Do +N(e^λt – 1)

Expanded expression to describe symbols: No. atoms of the daughter isotope in sample = No. of atoms of the daughter isotope in original composition + number of atoms of the parent isotope in sample (e^decay constant x age of sample – 1)

This knowledge can help us to date materials, the way we choose which radiometric dating method is best to used for each situation is by how many half lifes the material has been through. The more half lifes it has been through, the harder it is to get an accurate age so we choose different elements to use in radiometric dating. But what is a half-life? Half life is a statistical process and is never completely accurate, it is used to help scientists guess the around about ages of a material such as fossils and rocks. It is the amount of time it takes for a radioactive material to decay to point where only half of its original content is remaining.

The half of the element that ‘disappeared’ has experienced nuclear fission to form different elements. Carbon- 14 contains a half life of 5,730 years which implies that if you’re taking one gram of Carbon -14, half it’ll decay in 5,730 years. Or, if you leave Lead – 192 to undergo a half life, it will decay into part Lead-192 and part Thallium and Mercury. Every half life the element undergoes, the smaller the original sample element is in ratio to its by products. By looking at this ratio/ looking at the objects chemical composition, we can determine how many half lives the element has been through, therefore determining its age. This diagram shows that decay is exponential. The more half lives the thing has been through the harder it is to determine with certainty the exact age of anything (as it is only a statistical process).

Each half life only half of the original sample will remain ie, 1 half life = 50% left, 2 half lives = 25%, 3 half lives = 12.5%, 4 half lives = 6.25% … and so on so forth. Until the percentage gets so small it is hard to get an accurate result, this is when a more appropriate method of radiometric dating is to be used – an element with a longer half life. If you used more than one radiometric method to date a sample, you can compare results to conclude a likely range of the samples age (estimate).

The age of the Earth was determined by measuring lead content in a sample (product of uranium) U-Pb dating. This method was used because it had a longer half life than carbon for example. Depending on the situation, someone may choose Uranium isotopes over carbon isotopes to determine the age of a fossil (or artifact/ other material) because Uranium has a longer half life. So it is more appropriate for dating much older artifacts. The timeline of events is estimated by using both stratigraphy and several dating methods in conjunction estimate as accurately as possible. Cross-correlation of evidence from both Absolute and Relative dating methods is what allows geologists to make an accurate estimate of ages. It is these clues from what rocks look like and the order of the rock layers we can use as geological evidence to discover what happened and create a timeline of events. There is combination of sufficient evidence to support the leading theory of Cretaceous-Paleogene extinction event. From the stratigraphic evidence, analysing and dating rocks and fossils. Further proving that no, the Government did not place Dinosaur fossils to trick us. An asteroid really did begin the extinction of the Dinosaurs 65 million years ago.

Since the discovery of ancient dinosaur fossils, scientists have gone through extensive research to reveal the conditions of their lives on Earth and how many of them truly resided on our planet all those years ago. Yet despite all of our research, there is yet one baffling question we continue to ask today- which is, what exactly caused these daunting creatures to become extinct? Many theories were produced, supported by data collected from discovered fossils, including our own environment, which eventually lead to more prominent conjectures. One of them being the cause of an asteroid striking Earth millions of years ago, resulting in drastic changes throughout the planet’s environment. In order to attest this theory, there needs to be some form of evidence, which can be found through the remnants left here on Earth.

The discovery of a massive crater impact was found on the coast of Yucatan Mexico, now referred to as the Chicxulub crater, measuring “180 kilometers across, and occuring about 65 million years ago.” Writer Ker Than continues with the theory in their article, What Killed Dinosaurs: New Ideas about the Wipeout. They mention that in addition to the meteor’s impact, a series of catastrophic events followed, consisting of wildfires, large tropical storms, and discarded bit of asteroids plummeting directly towards our atmosphere. (Ker Than, 1) Any species close enough to the impact was immediately wiped out, but as for any other life residing beyond the initial collision, they had to face the consequences following afterwards. Particulate matter clung within the atmosphere thus blocking out the sun, causing decay in vegetation and harsh weather conditions.

As a result of the devastating affects this meteor left behind, a boarder of sediments was found circulating around the entire planet, typically known as the K-T boundary. It’s name is the abbreviated term for the specific era in which this occurred, the K being known for the Cretaceous period, and the T standing for the Tertiary period- “geologists have dated this period to about 65.5 million years ago.” (K-T Boundary, 1) Amidst the discovery of the K-T boundary, traces of iridium were found within its sediments, which an element found more commonly in space rocks. Studied by physicist Luis Alverez and geologist Walter Alverez, they determined that the concentration of the element was much higher than normal, “between 30-130 times the amount of iridium you would expect.” We also know that the geographical location of where the meteor struck explains why the boundary is much thicker in American and thinner in Italy. Additionally, since its crater was found near the Yucatan Peninsula, it would therefore make sense that higher traces of iridium are detected around America.

Other theories also suggest that high rates of volcanism was the cause of the dinosaur’s mass extinction. This theory also aligns with the discovery of iridium found along the K-T boundary. Chung-Tat Cheung explains more in depth within their article, Dinosaur Extinction. The traces of iridium originated from the planet’s core, and once the eruption took place, magma was then discharged along the surface, reaching about “1.5 miles (2.4 kilometers) thick over 1 million square miles (2.6 million square kilometers) of India.” Bob Strauss includes his input within his article, 6 Alternative Dinosaur Extinction Theories That Don’t Work. Although vital information disproves this theory, since five-million years is unaccounted for between the beginning of the eruption and the end of the Cretaceous period. (Strauss, 1) In a sense, both theories prove that the dinosaur’s extinction was the cause of both geology and astronomy. If in fact, a meteorite had collided into Earth all those years ago,the aspect of astronomy was in place, cataclysmically changing to the planet’s surface. Same can be said about a potential volcano eruption- which ties into the geologic aspect.

Meteors can typically be referred to as shooting stars, since they are known to have the capability of touching Earth’s atmosphere- the only difference is that it’s soon described as a meteorite once it reaches the planet’s surface. These instances only occur if the meteor is large enough to survive the harsh conditions of our atmosphere. What causes these rocks to break apart, is the process of entering a vacuumless environment to one that contains air. Typically, asteroids and meteors originate from the asteroid belt, between the two planets of Mars and Jupiter.

It’s also important to note, that given how plausible it was for a meteor to cause the extinction of dinosaurs- who’s to say we aren’t years, or even months away from another potential disaster? According to Marcia Smith of Space Policy online, Nasa receives an annual budget of over 21 billion dollars (https://spacepolicyonline.com/news/its-over-trump-signs-fy2019-appropriations-bill/, 1) A portion of this budget applies towards tracking the whereabouts of nearby meteors that have the potential of harming our planet. As of now, NASA has yet to detect any imminent threats, but their continual search has been a recurring practice since they began searching for near-Earth objects in 1970. Elizabeth Howell includes her input on NASA’s search for dangerous space anomalies in her article, Asteroid Defense: Scanning the Sky for Threats From Space. Within her article, it’s mentioned how, “congress directed NASA in 1994 to find at least 90 percent of potentially hazardous NEOs larger than 1 kilometer (0.62 miles) in diameter, which NASA fulfilled in 2010.

Congress also asked NASA in 2005 to find at least 90 percent of potentially hazardous NEOs that are 140 m (460 feet) in size or larger.” It was indicated that they were unable to complete within the deadline- near the year 2020, due to lack of funding. It’s important that our government continues providing income because as of 2014, NASA created a Planetary Defense Coordination Office, in which they conduct “tabletop” exercises’ with its partners to simulate threatening asteroids and an appropriate response.”

The production of these simulations may prove to be helpful if, in fact, we did encounter any similar fateful experiences. But there is also the possibility of avoiding any potential impacts altogether. Bruce Betts devices a list within his article, Five Steps to prevent Asteroid Impacts.

The first and foremost plan of action, is to seek out and find any deadly asteroid in space that appears threatening to our planet. What follows this step, is to begin tracking the asteroid’s trajectory and where it’s heading. Using tools such as telescopes, we can follow its predicted orbit.

The next thing to do, is to characterize the asteroids in order to specify things such as, “spin rate, and compositions.” Deflection would be our next course of action. Although there’s been various deflections techniques set up, they must undergo further testing in order for them to become fully developed. Theoretically, deflection can occur via gravity with the use of advanced spacecrafts engaging asteroids to a further location. The object can be broken apart forceful impact, or annihilated. The final step would depend on our ability to coordinate and educate. Within the article it’s mentioned that the effects of an asteroid striking Earth would affect us globally. Which is why it’s important that we are able to coordinate any plan of action internationally, thus increasing our likelihood of surviving the impact.