The author and his colleagues chose to focus on 375 million year old rocks in their search for fossils because amphibians that look dissimilar to fish were discovered in 365 million year old rocks, while fish without amphibian characteristics were discovered in 385 million year old rocks. Thus, it is possible that the evolutionary intermediary, or the “missing link” between fish and amphibians, would be discovered in 375 million year old rocks, between the two time periods. The rocks examined were sedimentary in composition, as the gradual and relatively gentle formation of sedimentary rock under conditions of mild pressure and low heat are conducive to the fossilization of animal remains. Sedimentary rock is also often formed in rivers and seas, where animals are likely to live. This site provides a resource that describes means by which fossils are formed and how the fossil record may be interpreted, and shows some examples of fossils demonstrating evolution through geological periods: http://www.fossilmuseum.net/fossilrecord.htm. In 2004, Shubin and his colleagues were looking for fossils on Ellesmere Island, in northern Canada. This location was chosen because of its lack of human development, as well as of obstructing natural formations and life forms such as trees, which
“Sex, Drugs, Disasters, and the Extinction of Dinosaurs” is written by Stephen Jay Gould, professor of geology and zoology at Harvard. This essay is one of more than a hundred articles on evolution, zoology, and paleontology published by Gould in national magazines and journals. It tells about scientific proposals for the extinction of dinosaurs – a confusing but an exciting problem that humanity tries to solve. By analyzing and describing each of the claims for the reptiles’ demise – sex, drugs, and disasters – Gould differentiates bad science from good science and explains what makes some theories silly speculations, while the other, a testable hypothesis.
The beginning of the Jurassic brought a new climate. The weather changed from arid, dry, and seasonal to humid, hot, and stable. The weather allowed for lush jungles to flourish, and with the lush jungles, the dinosaurs. The weather change was due to the supercontinent Pangea breaking apart. Two new smaller supercontinents were formed, Gondwana and Laurasia. The supercontinents now had more area that was touching the ocean. This meant the water from the ocean made the supercontinents more humid than before. The dinosaurs thrived in this climate. New species are being discovered to this day from the Jurassic Period due to the immense diversity amongst them.
“A minority disputes this theory, arguing that other events-such as volcanic eruptions, sea-level changes or a series of impacts-were to blame for the spectacular loss of species that occurred at the transition between the Cretaceous and Tertiary periods…”
While the author of the article believes that Brachiosaurus were aquatic animals, the professor disagrees with this statement. The professor points out that in spite of the fact that some species of dinosaur would spend a great deal of time in water, there was no possible that Brachiosaurus were aquatic ones. To strengthen her point, the professor provides sufficient evidence respectively to the points made in the article.
The animal is a Velocirapter. It is adapted to hunting in packs. 13. What evidence does Grant uncover pointing towards the dinosaur population breeding? Grant finds eggshells in the forest. 14. How does Malcolm explain the problem with the computer dinosaur tracking method? What does this data confirm?
The question of what caused the extinction of megafauna during the Late Pleistocene period is one that archaeologists have struggled to answer for decades, but why should it matter? Discovering with certainty the cause of megafaunal extinction would
Gould espouses more of the ideology of Williams and Colomb regarding why the theories of dinosaurs being incapable of having children and overdosing on psychoactive plants are entirely without merit. Williams and Colomb say, “we engage one another cooperatively in arguments, we aim not to coerce or seduce others into mindless agreement, but to enlist them into helping us to find the best, most reasonable solution to a shared problem”(67). Williams
Dinosaurs ruled the earth for over 65 million years and thankfully for the human race, they became extinct. Ultimately, only a major catastrophe could completely wipe out an entire species, let alone an entity of dinosaurs and the debacle on the causes of dinosaur extinction have flooded the minds of paleontologists for centuries. Geologist and zoologist Stephen Jay Gould published “Sex, Drugs, Disasters, and the Extinction of Dinosaurs,” to compare scientific and speculative causes of dinosaur decimation. Personally, I found this passage very informational and enjoyed reading it. Gould provides three theories that capture the reader’s curiosity, allowing room for pondering in one’s mind.
Sedimentary rocks interpret dinosaur habitats through encased environmental structures of the past. Through sedimentary rocks, paleoecologists’ can examine the arranged formation of sedimentary structures to specify what type of environment the dinosaurs’ lived in. An example of a specific sedimentary rock structure can be seen through formed weathering and ripple marks by how wind and sand formed distinct patterns in the past layered sediment. These arrangements provide interpretations on the structure of the sediment and the habitat of encased fossils, through modern day comparisons
The professor made the point that the edmontosaurs did not migrate south to survive the winter. On the contrary, the writer demonstrated idea that they did migrated to another region. Firstly, the professor suggests that although edmontosaurs fed only on plants, they do not have to migrate to warmer places. The
First and foremost, the author states that edmontosaurus fed exclusively on plants. But in the cold North Slope, it would have been no plants growing during the dark and cold winter. Therefore the edmontosaurus must have to move to the south region where it is warmer and more hospitable. On the contrary, the professor contends that 100 million years ago, the North Slope was
First, the reading avers that since in cold winter food could hardly found, the edmontosaur used to migrate to high temperature regions looking for plant food. While the professor demonstrates great disapproval to this analysis by stating that the edmontosaur didn't migrate in search of food. He then explains that about a hundred years ago the weather of North Slop was warm enough that let the vegetation grow in summer. How ever the vegetation might be died in winter but
BIOL2110- Vertebrate Zoology Word count: 1056 Dinosaur extinction: An analysis of events and theories that possibly led to the dinosaurs' demise.
Rapid climate change also ends up on the suspect list of possible dinosaur extinction events. During the latter part of the Cretaceous Period continents broke up causing volcanoes to erupt and fill the sky with gas and ash resulting in a drastic climate change (“Dinosaurs Climate Change and Biodiversity”). The shifting of continents changed the Earth’s landscape, altering weather patterns and overall climate (“Dinosaur Extinction Theories”). Also, over a long period of time, climate gradually changed. Ocean habits changed, temperatures grew much more extreme causing scorching summers and frigid winters (Norell, Dingus, and Gaffney). Radical temperature changes like these led to a green-house effect, making life for the dinosaurs a lot