How Did Male Dinosaurs Differ From Female Dinosaurs

Sexual dimorphism—a pronounced difference in size and appearance between the adult males and the adult females of a given species, over and apart from their genitalia—is a common feature of the animal kingdom, and dinosaurs were no exception. Its not unusual for the females of some species of birds (which evolved from dinosaurs) to be larger and more colorful than the males, for instance, and were all familiar with the giant, single claws of male fiddler crabs, which they use to attract mates. When it comes to sexual dimorphism in dinosaurs, though, the direct evidence is much more uncertain. To begin with, the relative scarcity of dinosaur fossils—even the best-known genera are usually represented by only a few dozen skeletons—makes it perilous to draw any conclusions about the relative sizes of males and females. And second, bones alone may not have much to tell us about a dinosaurs secondary sexual characteristics (some of which consisted of difficult-to-preserve soft tissue), much less the actual sex of the individual in question. Female Dinosaurs Had Bigger Hips Thanks to the inflexible requirements of biology, there is one surefire way to distinguish male and female dinosaurs: the size of an individuals hips. The females of large dinosaurs like Tyrannosaurus Rex and Deinocheirus laid relatively large eggs, so their hips would have been configured in a way to allow for easy passage (in an analogous way, the hips of adult human females are noticeably wider than those of males, to allow for easier childbirth). The only trouble here is that we have very few specific examples of this type of sexual dimorphism; its a rule dictated primarily by logic! Oddly, T. Rex appears to have been sexually dimorphic in another way: many paleontologists now believe that the females of this species were significantly larger than the males, over and above the size of their hips. What this implies, in evolutionary terms, is that female T. Rex were particularly choosy about selecting mates, and may have done most of the hunting as well. This contrasts with modern mammals like the walrus, in which the (much bigger) males compete for the right to mate with smaller females, but its perfectly in sync with (say) the behavior of modern African lions. Male Dinosaurs Had Bigger Crests and Frills T. Rex is one of the few dinosaurs whose females asked (figuratively, of course), Do my hips look big? But lacking clear fossil evidence about relative hip size, paleontologists have no choice but to rely on secondary sexual characteristics. Protoceratops is a good case study in the difficulty of inferring sexual dimorphism in long-extinct dinosaurs: some paleontologists believe that the males possessed larger, more elaborate frills, which were partially intended as mating displays (fortunately, theres no shortage of Protoceratops fossils, meaning there are a large number of individuals to compare). The same appears to be true, to a greater or lesser extent, of other ceratopsian genera. Lately, much of the action in dinosaur gender studies has centered on hadrosaurs, the duck-billed dinosaurs that were thick on the ground in North America and Eurasia during the late Cretaceous period, many genera of which (like Parasaurolophus and Lambeosaurus) were characterized by their large, ornate head crests. As a general rule, male hadrosaurs seem to have differed in overall size and ornamentation from female hadrosaurs, though of course, the extent to which this is true (if its true at all) varies significantly on a genus-by-genus basis. Feathered Dinosaurs Were Sexually Dimorphic As mentioned above, some of the most pronounced sexual dimorphism in the animal kingdom is found in birds, which (almost certainly) descended from the feathered dinosaurs of the later Mesozoic Era. The trouble with extrapolating these differences back 100 million years is that it can be a major challenge to reconstruct the size, color,  and orientation of dinosaur feathers, though paleontologists have achieved some notable successes (establishing the color of ancient specimens of Archaeopteryx and Anchiornis, for example, by examining fossilized pigment cells). Given the evolutionary kinship between dinosaurs and birds, though, it would not be a major surprise if, say, male Velociraptors were more brightly colored than females, or if a female bird mimic dinosaurs sported some kind of feathery display meant to entice males. We do have some tantalizing hints that  male Oviraptors were responsible for the bulk of parental care, brooding eggs after they were laid by the female; if this is true, then it seems logical that the sexes of feathered dinosaurs differed in their arrangement and appearance. A Dinosaurs Gender Can Be Hard to Determine As stated above, one major problem with establishing sexual dimorphism in dinosaurs is the lack of a representative population. Ornithologists can easily collect evidence about extant bird species, but a paleontologist is lucky if his dinosaur of choice is represented by more than a handful of fossils. Lacking this statistical evidence, its always possible that the variations noted in dinosaur fossils have nothing to do with sex: perhaps two differently sized skeletons belonged to males from widely separated regions, or of different ages, or perhaps dinosaurs simply varied individually the way humans do. In any case, the onus is on paleontologists to provide conclusive evidence of sexual differences among dinosaurs; otherwise, were all just fumbling in the dark.

Analysis Of Paul Laurence Dunbar s The Elevator Boy Poet

On June 27, 1872 in Dayton, Ohio a legend, a dream, a prodigy was born. Paul Laurence Dunbar was one of the first African American poets to gain national recognition. (poets) Dunbar graduated high school around the time where racial discrimination was at it’s all time high, so they were not many jobs for the African American race. Due to the lack of occupation Dunbar was forced to be an elevator operator in a Dayton hotel. Although the circumstances were difficult it did not stop Dunbar from succeeding. While working as an elevator operator, Dunbar was able to continue his works during his off time. Working at the hotel didn’t only allow Dunbar to continue writing; he also earned a name for himself, â€Å"elevator boy poet.† His eagerness to succeed allowed him to adapt what is now known as a hustle. Dunbar sold poems in the elevator for one dollar, to help cover publishing fees. Soon after Dunbar moved to Chicago, where he befriended Fredrick Douglass. This is w here his hard work begins to pay off. Dunbar and his work were mentioned in major magazines and newspapers. By 1896 Dunbar had published his third collection, but first professionally published volume, Lyrics of Lowly Life. In this volume Dunbar wrote a poem called, â€Å"We Wear the Mask.† In the poem, â€Å"We Wear the Mask†, lies and deceit, suffering, race, and society and class are used as themes to illustrate the African American life during and before Dunbar’s lifetime. The purpose of this analysis is to explore certain

Thrasymachus’ Views on Justice Free Essays

The position Thrasymachus takes on the definition of justice, as well as its importance in society, is one far differing from the opinions of the other interlocutors in the first book of Plato’s Republic. Embracing his role as a Sophist in Athenian society, Thrasymachus sets out to aggressively dispute Socrates’ opinion that justice is a beneficial and valuable aspect of life and the ideal society. Throughout the course of the dialogue, Thrasymachus formulates three major assertions regarding justice. We will write a custom essay sample on Thrasymachus’ Views on Justice or any similar topic only for you Order Now These claims include his opinion that â€Å"justice is nothing other than the advantage of the stronger,† â€Å"it is just to obey the rulers,† and â€Å"justice is really the good of another [†¦] and harmful to the one who obeys and serves. † Socrates continuously challenges these claims using what is now known as the â€Å"Socratic method† of questioning, while Thrasymachus works to defend his views. This paper seeks to argue the implausibility of Thrasymachus’ views through an analysis of his main claims regarding justice, as well as his view that injustice brings greater happiness. In Book I of Republic, Socrates attempts to define justice with the help of his friends and acquaintances. After a number of suggestions prove false or insufficient, Thrasymachus tries his hand to define the term, convinced that his definition rings true. Thrasymachus begins in stating, â€Å"justice is nothing other than the advantage of the stronger,1† and after prodding, explains what he means by this. Thrasymachus believes that the stronger rule society, therefore, creating laws and defining to the many what should be considered just. He pertains, however, that the stronger create said laws for their own benefit and therefore in acting justly, the ruled are performing for the rulers benefit and not their own. This argument is not feasible for a variety of reasons. One of the key characteristics of justice is fairness, which can also be defined as being reasonable or impartial. 5 Impartiality means that you do not favour one side over another6, and therefore implies that if one were to act justly and therefore impartially, they would not act in a way to benefit only a select few. Furthermore, justice in its true form cannot be used solely for the advantage of the stronger without the masses acknowledging the injustices being imposed upon them, as Thrasymachus suggests is the case. For justice is one of the many characteristics of morality, which is considered to be intrinsic based on an inner conviction. 7 Therefore, if the many were acting against said inner conviction wholly for the benefit of the stronger, would they not experience a natural feeling of injustice? This argument alike can be used to refute another of Thrasymachus’ primary claims that â€Å"justice is really the good of another [†¦] and harmful to the one who obeys and serves. †3 In addition to his definition, Thrasymachus argues the value of justice as a human or societal characteristic, claiming that injustice is far more beneficial to the individual. Thrasymachus asserts that tyranny: makes the doer of injustice happiest and the sufferers of it, who are unwilling to do injustice, most wretched. †¦] injustice, if it is on a large enough scale, is stronger, freer, and more masterly than justice. 5 To decide whether an unjust man finds more happiness than a just man does, one must understand the true meaning of the word. The dictionary defines happiness as â€Å"characterized by pleasure, contentment, or joy. †8 Thrasymachus typifies the unjust man as someone who is constantly seeking self-fulfillment, pleasing their desires no matter what the cost to others. It is in their nature to never be satisfied with what they have, and therefore it is unlikely that the unjust man could ever experience true contentment. In contrast, the just man is content upholding laws and acting for the greater good and is therefore capable of experiencing a greater happiness than one who partakes in injustices. The dictionary goes on to state that happiness can also be defined as â€Å"feeling satisfied that something is right or has been done right. 8 Thus, an unjust man could never truly be happy, as they are aware of the injustices they have committed unto others in order to benefit themselves. In addition, if one is to look to the cardinal virtues, not only is justice itself included, temperance is as well. Temperance, meaning â€Å"restraint in the face of temptation or desire†9 is not a characteristic of an unjust man. In fact, Thrasymachus argues that one should always seek to fulfill their own desires exercising injustice as a way to do so. Virtue is said to be a measure of one’s worth, therefore, in turning their back on it, an unjust man could never be as self fulfilled and happy as a virtuous one. The first book of Republic illustrates a diverse range of views in reference to the definition of justice. None, however, evokes such controversy and analysis as Thrasymachus’ dialogue. His point of view calls to the forefront a number of important questions regarding the issue, and is an essential piece to Plato’s puzzle of defining justice. Thrasymachus’s arguments in and of themselves, however, are implausible as discussed above. Not only does his claim that â€Å"justice is nothing other than the advantage of the stronger,†1 go against morality and assume the masses naive, but his attempt to prove that the unjust man is happier than the just man is insufficient and untrue. Works Cited Encarta World English Dictionary. 2004 Plato. The Republic. Translated by G. M. A. Grube. Revised by C. D. C. Reeve. Indianapolis/Cambridge: Hackett Publishing Company. 1992. 382c How to cite Thrasymachus’ Views on Justice, Papers