Ordovician Life

The author and his colleagues specifically chose to focus on 375 million year old rocks in their search for fossils because this was the time frame that provided fish that would be useful to study from. The 385 million year old rocks provided fish that look too similar to the ones we have now and the 365 million year old rocks have fossils that don’t resemble fish. The 375 million year old rocks, however, provide fossils that show the transition between fish and land living animals.

There was also a surprising discovery. The fossil of the horseshoe crab is preserved as an exterior and interior mold. The fossil preserved traces of activity by other organisms. The interior mold shows traces left by small invertebrates, that fed on the horseshoe crab after it died. These worms created the mold of the fossil, and the detail was so detailed that the artificial case\t was almost an exact replica. This was very surprising and awesome because this shows how invertebrates can preserve other animals anatomies. The reason for this being: soon after the horseshoe crab died, the worms began to settle upon the horseshoe crab. The worms began building homes, and the tubes took form of the dead horseshoe crab. Because of the rate the worms created their homes, the author predicts the horseshoe

Evidence  for  life  on  early  Earth  (e.g.  in  the  Pre Cambrian)  has  proved  difficult  to  find  because: SELECT  ALL  THAT  APPLY Select  one  or  more: A.  rocks  from  these  early  times  are  rare  due to  the  recycling  of  the  Earth's  crust  through plate  tectonics   B.  there  was  no  oxygen  in  the  Earth's atmosphere  at  this  time C.  life  at  this  time  lacked  hard  parts  (such as  shells  or  bones)  that  fossilise  easily   D.  life  had  not  yet  emerged  onto  land E.  life  at  this  time  was  mostly  microbial

Examination of the fossils and the strata in which they were found and compilation of this data into what is known as the fossil record provides a comprehensive picture of the morphology and physiology of the organism, how they evolved over time and even of the terrain and vegetation cover at that time period. Lower strata

During the Ordovician Age, the Earth had milder climates than before. The air in the atmosphere was warm and wet. Sea levels kept rising but leveled off in the middle of the period. At the beginning of this time, it was very hot, marine waters estimated around 113 degrees fahrenheit. Over time, the ocean became cooler and the temperature became comparable to today’s equatorial waters.

The fossil of Tiktaalik confirmed a major prediction of paleontology in that it showed characteristics of both aquatic animals, such as fish, and land animals, such as reptiles and amphibians. While it had fins and scales, it also had a flexible neck, a flat head, and complex bone structure in its fins that correspond with the structure of the legs of terrestrial animals. Thus, it demonstrates the evolutionary transition between aquatic and terrestrial life.

I found on the website http://nationalgeographic.org/media/pterodactyl-fossil/, that the pterodactyl had been living in about the Jurassic period or 150 million years ago.

Stromatolite forms and is the first organisms on the earth they were formed by very thin layers of single-celled organisms.

The Cambrian era was over 500 million years ago, according to many scientists’ studies. It got it’s name “Cambrian” from the Roman word Cambria which acts as a name for

Mesozoic vertebrates of Texas have received less attention than Paleozoic. In the early 1900s E. C. Case collected and reported amphibians and reptiles found in Triassic sediments along the eastern edge of the High Plains, and Sankar Chatterjee of Texas Tech University has also made important discoveries there. Notable are skeletons of phytosaurs. These aquatic reptiles, up to thirty feet in length, had elongated snouts armed with thick, sharply pointed teeth. Their habits were probably much like those of modern crocodiles. Some lightly armored forms were not unlike crocodiles in appearance, except for their long, hook-nosed snouts, but some armored types of phytosaurs may have looked almost like arthropods. Through work centered at the University of Texas at Austin, parts of the Trans-Pecos region have yielded important fossils of Cretaceous reptiles, among them enormous crocodiles and the largest known pterosaur. Much of Central Texas probably contains bones of Cretaceous vertebrates, but the land is so heavily vegetated that discoveries are few. However, remains of dinosaurs, plesiosaurs, and even primitive mammals have been found and are preserved at the University of Texas and Southern Methodist University. Fossil vertebrates, especially mammals, of the middle to late Tertiary and Pleistocene ages abound in Texas. Much of the fossil history of horses, camels, rhinoceroses, and other kinds of both living and

During this time, there were two major animal groups that settled on land. There were tetrapods, who were the first vertebrates to walk the land and the first terrestrial arthropods, which included wingless insects and early arachnids. The Devonian period was also known as the Ages of Fishes, because there was an abundance of diverse fishes at that time. The first fishes didn’t have jaws and their support structure was made of cartilage, later they developed jaws, gills, and fins and the first sharks and bony fish appeared. Most of the land masses formed two neighboring supercontinents named, Gondwana and Euramerica. Water covered the rest of Earth. Plants started covering the land where they developed vascular tissues which allowed them to

The late Devonian extinction events were actually two sharp pulses of death about 360 million years ago, each just 100,000 to 300,000 years apart. Each pulse was accompanied by a massive drop in temperature, with the steaming seas of the Devonian—surface temperatures of which were about 93 degrees F (34 degrees C)—dropping to about 78 degrees F (26 degrees C), "and marine organisms would not have liked that at all," McGhee said. As to what caused these cold snaps, the ever-popular suspects are ash and dust kicked up by either astronomical impacts or massive volcanism. At that time, plants had made it onto land, as had spiders, scorpions and similar creatures. Right before the extinction events, the first proto-amphibians

dinosaurs from the Mesozoic era, and are consequently referred to as Teleosts, the title of the infraclass for seahorses and a myriad of other species (SFSU Geography and Dames N 2000). Refer to Figure 4 for a visual representation of Hippocampus ancestry and adaptations. Teleosts, which were believed to have evolved roughly two hundred million years ago, are commonly called bony fish in reference to their evolved tail bones and new dorsal fins, additions that granted Teleosts heightened mobility, agility, and predatory skills (SFSU Geography and Dames N 2000). The slowly evolved absence of caudal fins made specialization and adaptation a necessity for Syngnathids (SFSU Geography and Dames N 2000). The first of the Syngnathids, the Pipefish, was believed to arise about fifty million years ago from the Eocene Epoch and gave way to the slender, reed-like bodies

The Phoenicians were an Ancient Civilization, that had many independent city-states.The years that the Phoenicians lived was 1550 BC to 300 BC.Many generations of Phoenicians thrived, because they had many city-states. The Phoenicians lived on the western end of the fertile crescent. While living on this beautiful land it allowed them to have very good crops, since they had such rich soil. Since there were so many Phoenician civilizations they spread across the coast of the Mediterranean Sea. Their territory was called Phoenicia, however this area is now the modern day countries of Syria, Lebanon and Northern Israel.

However, even before we set our fleshy feet on the earth’s soil, there have been different life forms that came before us. It all started from the single-celled organisms such as algae and bacteria evolving to multicellular organisms such as plants and animals. They were the pioneering residents of this blue planet. Everything was flourishing for a while. Numerous life forms were continually popping out. The earth that was once, quiet and barren, is now teeming with life. Organisms come in various size, shape, and composition. A shapeless amoeba that is hundreds of micron small alongside a brachiosaurus that is twenty meters tall is a good example for this. I would like to say that all of the living creatures on