Ichnology and the study of trace fossils is a valuable tool for unlocking the past biology of the planet, and giving information on behaviour, movement, and feeding patterns. The Mesozoic era, or the “Age of Dinosaurs”, ranged from 252-66 Ma and saw the world dominated by huge reptiles, some of which have been preserved in the fossil record. Over the years Australia has produced very informative dinosaur fossils, some of which are body fossils, but others being trace fossils, usually footprints. Body fossils have proved useful in determining the morphology of prehistoric creatures, but the trace fossils are the true key to unlocking how they might have lived millions of years ago.
The Australian fossil record for dinosaurs from the Triassic
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The second of the two, which is the oldest, were also found in the Coal Measures in an area called Dinmore by students seeking plant fossils. These tracks are dated Mid to Late Carnian, grouping them amongst some of the oldest dinosaur tracks in the world (Thulborn, 1998). The tracks in question consisted of six prints varying in quality of preservation, all occurring in fragile fine-grained shales and siltstones. The best preserved footprint came to 7cm in length and clearly showed three pointed digits indicating the track-maker was tridactyl dinosaur (Thulborn, 1998).
In the study, the best print was used for comparative data to determine the degree of similarity to a small theropod and ornithopod. For most aspects the print obtained ratios closest to the theropod data, except for the total divarication of digits II-IV being larger than expected. However, this was explained by the dinosaur’s toes spreading slightly when the foot made contact with the muddy substrate (Thulborn, 1998). With these conclusions made it was deemed a part of the ichnogenus Grallator (Hitchcock, 1858) which is most commonly associated with theropod
Ceratopsians and Pachycephalosaurs are closely related in their characteristics. Ceratopsians processed a saddle-shaped boney frill that extended from the skull to the neck and typically had horns over the nose and eyes. The most popular was the triceratops, which could reach over 26 feet and weigh in excess of twelve metric tons. Their frills served as two major functions. It protected the vulnerable neck from being harmed. The second major function that the frill provided was due to the fact that the frill contained a network of blood vessels on its underside, which were used as a means to get rid of excess heat. The Pachycephalosaurs were considered to be bipedal. They were also found to have thick skulls, flattened bodies, and tail that were covered in an array of body rods. Pachycephalosaurs were thought to have been more than fifteen feet long and processed a skull that was surrounded by a rounded dome of solid bone. It was thought that they used their heads in combat or mating contests, but that was disproved fairly recently, which I will discuss later in the paper. Both Ceratopsians and Pachycephalosaurs were “bird-hipped” and both of these suborders contained a backwards pubic bone. Both were Marginocephilia, or “fringed heads”, which is one of three clads under the Orinthiscia order. They were also herbivore dinosaurs that inherited their fringe at the back of the skull from earlier ancestors.(2) Their classi...
Majungatholus atopus roamed the plains of northwestern Madagascar about 70 million years ago during the Late Cretaceous (Perkins, 2003; Rogers et al, 2003). The discovery of 21 tooth-marked elements originating from two Majungatholus atopus individuals suggests evidence that the dinosaur supplemented its diet by feeding on its own dead or hunting them (Rogers et al, 2003). It cannot be confirmed whether they were purely scavengers, hunters, or both. Scientists are certain that the marks are not the doing of any other predator because the teeth marks are not consistent with any other known species that lived in the area. Only one other theropod that inhabited the area during the time Majungatholus atopus did, Masiakasaurus knopfleri, had teeth and bite marks too small to have caused these markings. Two large crocodile species also shared the same ecosystem but their teeth were “too blunt and too irregularly spaced to have produced the narrow grooves found on the Majungatholus bones”(Perkins, 2003). The tooth marks on at least nine Majungatholus elements attest to intertooth spacing in the perpetrators jaw and denticle drag patterns consistent enough to make a compelling case for Majungatholus feeding on other Majungatholus (Rogers et al, 2003).
The difficulty in re-constructing dinosaurs for television and movies lies in the fact that not everything can be preserved. Fossilized bones create the skeleton of a dinosaur, thereby allowing scientists to study how they moved, how big they grew, and how different body parts worked as a whole. But what children see on television: the scaly green skin of the brontosaurs or the brown hair of a mastodon may not hold much fact. Unfortunately, particular physical features cannot be fossilized. Skin, cartilage, hair and other soft tissues usually decay before leaving science no clues to what these dinosaurs truly looked like. The public also cannot know the social behaviors of dinosaurs. Movies generally portray all carnivores like the T-Rex as monstrous bullies while the larger vegetarians all seem slow and peaceful. Up until recently, no hard evidence can be found to help support or dismiss any of these stereo-types. In the barren deserts of Argentina, a team of scientists from the National Geographic Society came across a massive graveyard of fossilized dinosaur eggs. In 1997, Dr. Luis Chiappe and Dr. Lowell Dingus discovered a rare opportunity to finally study the external functions of an ancient creature that contained fossilized teeth imprints, embryos and skin impressions. This unearthing unlocks endless prospects to learn about dinosaur behavior and external attributes, topics which used to be some of the most problematic areas of study. The most remarkable aspect, of course, is how the most delicate of information is found within an egg.
Dinosaur fossils are one of the few ways in which scientists can study the history of life on earth millions of years ago. Each new discovery is unique in its own way and provides valuable information about the past. No two finds are exactly identical; therefore, when dinosaur remains are uncovered, the possibility and excitement of new information or even a new species exists. Until the year 2000, no dinosaur has ever been found with a fossilized heart. Scientists at North Carolina State University and the North Carolina Museum of Natural Sciences discovered a sixty-six million year old Thescelosaurus with a heart.
The idea of cloning dinosaurs and other prehistoric life became popularized by the 1992 film Jurassic Park (based on Michael Crichton’s 1990 novel). Though it may have sparked new interest into the field of paleontology, it did so with deceiving inaccuracies. However, the technical fallacies of the actual dinosaurs are somewhat forgivable as it added to the film’s dramatic appeal. Velociraptor, as depicted in the film, was about the size of a grown man. In reality, velociraptor came to about the kneecap. Furthermore, velociraptor would more likely have been covered in feathers rather than the lizard-like skin portrayed in the movie. One scene shows velociraptor fogging the window of a door. This is an endothermic or warm blooded trait as it implies the dromaeosaurid’s body temperature is above the temperature of his environment. There is also no evidence of dilophosaurus bearing a neck frill, and brachiosaurus did not have the ability to chew his food in a circular motion (iguanodon was the first dinosaur to develop this technique by acquiring back molars to allow for equine or bovine-like chewing). Fortunately, tyrannosaurus remained very close to his biological authenticity, with the only paleobiological errors stemming from a lack in computer animation such as rudimentary ball and joint programs. However, the erroneous nature of the deoxyribonucle...
Dinosaurs are often compared to and resemble modern day reptiles. Scientists will study how these modern day reptiles behave, look, act, and move to draw conclusions on how the dinosaurs would behave, look, act, and move. They also look at the intern make-up of the modern reptiles to predict how the dinosaurs internal make up would be. However, a recent discovery in South Dakota is stirring up some controversy (Hesman). While Mike Hammer was walking around a ranch in South Dakota he stumbled across a “big-eyed” dinosaur that he now refers to as Willo. The thing that caught his eye was the chest cavity of the dinosaur, upon further investigation he found a rock that was preserved in the curve of the dinosaur’s ribs, he was convinced that this rock was once a heart. Hammer then went on to take the dinosaur fossil in for a medical X-ray scan, this X-ray showed evidence that could change how we think about dinosaurs.
Every so often a discovery is made that attempts to shake up pre-conceived notions of how the dinosaurs actually lived or how they came to be. On June 22, 2000, in Oregon, scientists announced the discovery of the oldest known animal to have feathers. Though no records indicate how the age of the animal was determined, the fossil was dated at 220 million years old. It lived at the time of the very earliest dinosaurs, and about 75 million years before the first known bird.1[1]
Palaeogeography deals with the reconstruction of physical geographical conditions for the eras of the Earth's history. The term comes from the Greek παλαιός (palaiós) meaning ‘old’ and γεωγραφία (geōgraphía) meaning ‘a description of the earth’ and seems to have been introduced in the Earth sciences vocabulary as ‘Palaeo-Geographie’ by Ami Boué (1794‒1881), a French‒Austrian geologist, in his publication Einiges zur palaeo-geologischen Geographie (Boué, 1875, p. 2). Palaeogeography focuses on the distribution of land and sea, the spread of mountains and volcanoes and the expansion of glaciations, among others. The results are presented in geographic depictions called palaeogeographic maps. A special kind of palaeogeograpahical map is palaeobiogeographical maps depicting the distribution of
The Jurassic environment that Updike constructs in his short tale invites interpretation. First, the majority of the dinosaurs described were found, as one would expect, in the middle to late Jurassic period. By the Cretaceous period, the era that followed the Jurassic, these species had largely faded into obscurity, replaced by huge sauropods. Indeed, the only species in Updike's tale that falls into this class of Cretaceous sauropods are the brontosaurus and the diplodocus, both of which are held in high regard by the narrator. One can clearly infer from this evidence that, though Updike titles hi...
Dinosaurs are an extinct group of animals that thrived for 165 million years starting 230 million years ago in the Late Triassic period of the Mesozoic Era. Despite being extinct for the past 65 million years and not being able to study them in their true form, scientists have been able to estimate many different behaviors of dinosaurs. This paper will show that the close study and examination of different types of body and trace fossils, along with animal models, can be provided as evidence to estimate different types of behaviors in dinosaurs. The different types of behaviors examined below will fall into the categories of: mating; reproduction and nesting; social lives; locomotion; feeding; and fighting. To begin, a great deal of information gathered from fossils and compared to living animal models have been used to estimate mating behaviors.
This article was also particularly interesting to me because this is a recent find and there is little to no literature published concerning the idea that dinosaurs may have been cannibals. This is a new fossil find in which makes any and all research being administered equally as important. The time period of these fossils date back nearly 65 to 75 million years ago to the late –Cretaceous period when dinosaurs neared the end of their existence on earth. The fossils that have been discovered that tend to persuade researchers to believe dinosaurs were cannibals have been located in Northwest Madagascar’s bone beds. Rogers states, “ Fossilized soil samples from the same region are red and oxidized, hinting that the area was arid, with food in short supply. The animals may have traveled to the river to find sustenance and died there.
The debate of whether dinosaurs were cold blooded or warm blooded has been ongoing since the beginning of the century. At the turn of the century scientists believed that dinosaurs had long limbs and were fairly slim, supporting the idea of a cold blooded reptile. Recently, however, the bone structure, number or predators to prey, and limb position have suggested a warm blooded species. In addition, the recent discovery of a fossilized dinosaur heart has supported the idea that dinosaurs were a warm blooded species. In this essay, I am going to give supporting evidence of dinosaurs being both warm and cold blooded. I will provide background information on the dinosaur that was discovered and what information it provides scientists.
With its abundance of genera, the Burgess Shale is one of the world’s most important fossil fields. It’s discovery in 1909 led to over 100 years of paleontological study in the Canadian Rockies, a majority of which has been carried out in two quarries known as the Walcott and Raymond quarries (Hagadorn, 2002). Though he was originally in search of trilobites in the Burgess Shale Formation, paleontologist Charles Walcott also discovered a diverse group of soft- and hard-bodied fossils, from algae and sponges to chordates and cirripeds (Hagadorn, 2002). Soft-bodied fossils are incredibly rare due to their delicate structure and susceptibility to decay, so it is hard-bodied fossils that more regularly occur in fossil findings. However over 75,000 soft-bodied specimens have been found in the Burgess Shale formation (Hagadorn, 2002). These specimens are preserved in layers of shale formed from deposits of fine mud. One of the most significant species discovered is the Pikaia gracilens. Believed to be an early chordate, the Pikaia gracilens existed very close to the beginning of the evolutionary path that ultimately lead to humans (McGraw-Hill Encyclopedia, 2006).
Norell, Mark, Lowell Dingus, and Eugene S. Gaffney. "Why Did Nonavian Dinosaurs Become Extinct?" Discovering Dinosaurs: Evolution, Extinction, and the Lessons of Prehistory. Berkeley: U of California, 1995. N. pag. Print.
Reptiles are vertebrate, or backboned animals constituting the class Reptilia and are characterized by a combination of features, none of which alone could separate all reptiles from all other animals.The characteristics of reptiles are numerous, therefore can not be explained in great detail in this report. In no special order, the characteristics of reptiles are: cold-bloodedness; the presence of lungs; direct development, without larval forms as in amphibians; a dry skin with scales but not feathers or hair; an amniote egg; internal fertilization; a three or four-chambered heart; two aortic arches (blood vessels) carrying blood from the heart to the body, unlike mammals and birds that only have one; a metanephric kidney; twelve pairs of cranial nerves; and skeletal features such as limbs with usually five clawed fingers or toes, at least two spinal bones associated with the pelvis, a single ball-and-socket connection at the head-neck joint instead of two, as in advanced amphibians and mammals, and an incomplete or complete partition along the roof of the mouth, separating the food and air passageways so that breathing can continue while food is being chewed. These and other traditional defining characteristics of reptiles have been subjected to considerable modification in recent times. The extinct flying reptiles, called pterosaurs or pterodactyls, are now thought to have been warm-blooded and covered with hair. Also, the dinosaurs are also now considered by many authorities to have been warm-blooded. The earliest known bird, archaeopteryx, is now regarded by many to have been a small dinosaur, despite its covering of feathers The extinct ancestors of the mammals, the therapsids, or mammallike reptiles, are also believed to have been warm-blooded and haired.