Fossils have been discovered and collected by early man dating back thousands of years. Evidence of this has been exhibited in many ancient cultures throughout the world. Trilobite fossils have been found in early human burial sites dating back thousands of years. In the Far East, Europe and throughout Asia the indigenous inhabitants discovered large dinosaur bones and believed them to be “Dragons” or “Giant Human Beings” that once roamed the earth. Well we have come a long way since then, however not it was not until the 1800’s that dinosaurs were studied, collected and described with much more scientific scrutiny.
The name dinosaur is a derivative of Greek meaning “terrible lizard”. This description originated and was coined in 1842 by an English paleontologist, Richard Owen. When he began studying the fossil remains of what we know now to be an Iguanodon along with several other similar species, he classified these creatures as “Dinosaurs”
During these early years of dinosaur fossil study, scientists believed these creatures walked on four legs comparing them to known lizard species of the day like the Iguana, thus the name Iguanodon. This dinosaur-looking creature that we see in old movies had us intrigued however movie makers did not get it right until Jurassic Park. This would all change due to the discovery in 1858 when an American dinosaur was found in the small town of Haddonfield, NJ. The fossilized creature discovered was almost a complete skeleton and was named Hadrosaurus. Studying the almost complete skeleton, scientists deduced from its skeleton that this creature was bi-pedal and walked on two feet instead of four!
This discovery sparked a great interest amongst scientists of the time and the relentless search began in the scientific community. This began the race for dinosaur discovery what is known as the “Bone Wars”. A feud between competing scientists from the 19th century began and lasted for over 25 years.
The competing fossil hunters were Edward Drinker Cope and Charles Marsh. Together Cope and Marsh discovered a total of 142 new species, of which Cope’s discoveries are at the American Museum of Natural History in New York and Marsh’s collection is now in the Peabody Museum of Natural History at Yale University in New Haven, Connecticut.
Dinosaur fossils now have been found on every continent in the world including Antarctica! Presently scientists are exploring areas in South America, China, India, and Madagascar. We cannot wait to see what new and incredible discoveries await! Since those early days we now know that dinosaurs once believed to be cold blooded like lizards and sluggish, were very active, fast moving and warm blooded. Dinosaurs were warm blooded like mammals and extremely active and adapted to hunting, caring for their young and exhibiting other extraordinary behaviors, like flight!
Dinosaur fossils found in China are particularly valuable in the sense that many fossils found there have plumage-like or feather-like body coverings. Specific discoveries of this nature has led paleontologists to believe that birds are descendants from the “bird hipped” dinosaurs, called ornithischians. However, there is some debate regarding how to define and where on the dinosaurian evolutionary chart do birds fit. Archaeopteryx, the Bird-like Dinosaur or the Dinosaur-like Bird, as some may choose, is a “Transitional Fossil”. Discovered in Germany during the mid 1800’s, this famous and highly detailed “Bird/Dinosaur” fossil clearly shows plumage surrounding its delicately preserved skeleton. This important transitional fossil shows the early link between dinosaurs and birds and is thought to be the earliest known example of this transitional link. Currently new discoveries from various parts of the world such as China may soon dethrone Archaeopteryx as the earliest known Bird/Dinosaur transitional fossil. Stay tuned to our New Fossil Discovery section in http://www.FactsAboutFossils.com.
Approximately 235 million years ago, Dinosaurs started to diverge from their Archosaur (Ancient Lizard) ancestors during the Triassic Period. After the Permian–Triassic extinction event that wiped out an estimated 95% of all life on Earth, the fossil record shows small bipedal dinosaur-like creatures. After the Permian Period 250 million years ago, dinosaurs became the dominant terrestrial group for about 135 million years until another extinction event occurred in the Cretaceous approximately 65 million years ago.
Paleontologists have identified over a thousand species of dinosaurs on every continent throughout the world and counting. Only a very small percentage of dinosaur fossils have been found and even a smaller percentage of dinosaurs were fossilized in nature. So working with the current fossil record information we believe that dinosaurs ranged from the size of a sparrow to the size of a bus. The largest dinosaur that ever lived is believed to be over 190 feet in length and weighted over 250,000 pounds. Its height was as tall as a six story building. During all of the Mesozoic dinosaur era, the sauropods were the tallest, longest and heaviest dinosaurs that ever roamed the earth.
The largest known carnivorous dinosaur, as seen in Jurassic Park III was Spinosaurus with its sail like structure on its back, weighted about 9 tons and was 50 to 60 feet in length. Tyrannosaurus, Giganotosaurus, Allosaurus and Carcharodontosaurus were somewhat smaller than Spinosaurus but just as fast and as deadly a predator. Most of the smaller known dinosaurs, those that were closely related to birds were about the size of a black bird. However, the smallest known dinosaur/bird was Anchiornis (which means “near bird”) only weighted about 4 ounces.
During the Jurassic Period dinosaurs were globally distributed and became diversified. Fossils have been found on every continent on earth. More than 200 million years ago in the Late Triassic and Early Jurassic, the continents were in different locations than they are today and were bunched together into a single land mass called Pangaea. The wide distribution of dinosaur and plant species throughout Pangaea is demonstrated by all the similar fossil discoveries and findings distributed throughout the world today. The Conifers which exist today are pine cone type of trees and shrubs which were prolific during the time of dinosaurs and were a food staple for many of the non-carnivorous dinosaurs. To help these herbivore dinosaurs with digestion, many large sauropods would swallow “gizzard stones” to help mash up the thick vegetation for digestion. These gizzard stones as well as fossilized Dino-Dung (Coprolite) help scientists study dinosaur diet. Dinosaurs exhibited other interesting behaviors that are worth mentioning in our next article.
Common behaviors in modern birds, crocodilians and dinosaurs are egg laying and nesting behaviors. Many bird species today thrive in flocks and it is believe that dinosaurs exhibited the same behavior such as moving in herds or flocks and mass nesting behaviors. A nesting area of Maiasaura, a large duck-billed dinosaur was discovered in 1978. As early as 1878 a mass death site of iguanodon fossils, both juvenile and adults were also found together. They may have perished together in a flash flood or were all trapped in a deep mud hole. This suggested a moving herd of these creatures.
Also foot prints and track-ways indicate that some species traveled in herds during migrations and for protection of their young against predators. Very much like the Wildebeest in Africa travels in herds and protects itself against the predatory big cats. It has also been suggested that some of the carnivorous dinosaurs were pack hunters with coordinated attacks on herding dinosaurs which would also support evidence of herding.
As in bird and crocodilian species of today, the nesting areas of duck-billed dinosaurs discovered in Montana demonstrates that parental care was present as well. Many dinosaur nests and eggs have been found representing different groups of dinosaurs. Like birds today dinosaurs cared for their young prior to and perhaps after hatching. One amazing discovery in 1993 depicts an Oviraptor (egg thief) dinosaur species covering its eggs with its wings and spread over its brood. Perhaps a last attempt of protection before it was covered by sediment debris. Scientists originally believed this creature was stealing and eating the eggs of some unsuspecting creature, however subsequent evidence has led paleontologists to now know it was a position of protection.
During the late Cretaceous Period it is generally believed that a meteor was responsible for the extinction of dinosaurs which occurred approximately 65 million years ago. It is believed that this impact caused the extinction of all dinosaur groups. The survivors of this event are lizards, turtles, birds and crocodilians that live today, however, many other species became extinct in this event as well. The general consensus is that a meteor impact was the primary cause of the extinction of dinosaurs, however it is also believed that other factors contributed to these extinctions.
During the Mesozoic Era CO2 levels were more than 10 times higher than today and O2 levels comprised over 30% rather than 21% O2 today. During the late Cretaceous Period drastic atmospheric changes started to occur. Volcanic activity during this period slowed which led to a cooling period due to decreased carbon dioxide in the atmosphere. During this cooling period sea levels dropped, as well as atmospheric oxygen levels. Due to these simultaneous events and changes including, the huge meteor impact and changes in the flora contributed collectively to the extinction of many species on earth as well as the Dinosaurs.