Marsupialia

“ The great order, or rather division, of mammalia, the Marsupialia, [153] is furnished with a pouch, into which the young are received and nourished at a very early period of their existence. The first species of the group, known to voyagers and naturalists, was the celebrated opossum of North America, whose instinctive care to defend itself from danger causes it to feign the appearance of death. As the great continent of Australia became known, it was found that the great mass of its mammalia, from the gigantic kangaroo to the pigmy, mouse-like potoroo, belonged to this singular order. ”

“ Even such imperfect knowledge as we possess of the ancient mammalian fauna leads to the belief that certain of its types, such as that of the Marsupialia, have persisted with no greater change through as vast a lapse of time. ”

“ Afterwards come land animals, of which the first are reptiles, universally allowed to be the type next in advance from fishes, and to be connected with these by the links of an insensible gradation. From reptiles we advance to birds, and thence to mammalia, which are commenced by marsupialia, acknowledgedly low forms in their class. ”

“ In the same manner as animals are adapted to natural limits in their large primitive groups which we call classes, we find also the minor divisions more closely adapted to particular circumstances of the physical condition of all parts of the globe. Among Mammalia, the great type of Marsupialia is placed in New Holland, and extends little beyond that continent into the adjacent islands. A very few representatives of that family are found in America. Asia, Africa, the colder parts of North America, and its southern extremity, are entirely deprived of this type. ”

“ To find living, in a state of nature, any member of the kangaroo's order, we must at least cross the Atlantic.
When America was discovered by the Spaniards, among the animals found there, and afterward brought over to Europe, were opossums, properly so called—marsupials, of the family Didelphidæ, which extend over the American Continent, from the United States to the far South. These creatures were the first to make known to Europeans [4] that habit of sheltering the young in a pouch which exists in the kangaroo, and which habit has given the name Marsupialia to the whole order. ”

“ History of British Fossil Mammals and Birds.
[269] It may be as well, also, to observe here that the learned Professor's article on the Marsupialia, in the same work, leaves little to be desired by the student who desires fuller information on the comparative anatomy of the marsupial animals.
[270] Mr. Gould, in his introduction, says 181 species, and his table shows 172; but we think he has erred in placing some birds under the head of Van Diemen's Land, which in the body of his book do not appear ever to have been found in it. ”

“ When those phalanges are clad with hoofs or covered by a nail they end in a rounded and flattened termination. On the other hand, when they bear a claw they are themselves sharpened at the extremity and often grooved above.
The Marsupium.—It may appear to be unnecessary at this juncture to speak of the marsupial pouch, which is so usually believed to be a characteristic of the group Marsupialia. Rudiments of this structure have, however, been recently discovered in the higher mammals, and, as Dr. ”

“ Here may be noticed three genera of large extinct marsupials from the Pleistocene of Australia whose affinities appear to ally them to the wombat-group on the one hand and to the phalangers on the other. ”

“ Marsupial bones unossified. The gradual passage of the thick root of the tail into the body is a character common to the Tasmanian wolf and the aard-vark, and may be directly inherited from reptilian ancestors (see Thylacine) . ”

“ Side by side with this wonderful outgrowth of the mammalian type, in the first plasticity of its vigorous youth, the older marsupials die away one by one in the geological record before the faces of their more successful competitors; the new carnivores devour them wholesale, the new ruminants eat up their pastures, the new rodents outwit them in the modernized forests. At last the pouched creatures all disappear utterly from all the world, save only Australia, with the solitary exception of a single advanced marsupial family, the familiar opossum of plantation melodies. ”

“ Returning now to our subject from this geological digression—which will hardly be deemed unprofitable, since I have given you in few words the results of a great deal of my own hard mountain work—let us consider the Tertiary mammals, as we know them front the remains already discovered, and attempt to trace the history of each order down to the present time. We have seen that a single small Marsupial, from the Trias, is the only mammal found in all the American rocks below the Eocene; and yet in beds of this age, immediately over the Chalk, fossil mammals of many different kinds abound. ”

“ We had a glimpse of the museum, by courtesy of the American gentleman who is curator of it. It has samples of half-a-dozen different kinds of marsupials— [A marsupial is a plantigrade vertebrate whose specialty is its pocket. In some countries it is extinct, in the others it is rare. The first American marsupials were Stephen Girard, Mr. Astor and the opossum; the principal marsupials of the Southern Hemisphere are Mr. Rhodes, and the kangaroo. I, myself, am the latest marsupial. Also, I might boast that I have the largest pocket of them all. But there is nothing in that.] ”

“ See the Noun.
Marsupial, n. an animal in which the female has an abdominal pouch in which the young, born in a very immature state, are carried. (Lat. Marsupium = a pouch.) At the present day Marsupials are only found in America and the Australian region, the greater number being confined to the latter. See quotation 1894, Lydekker.
1848. W. Westgarth, `Australia Felix,' p. 129:
"The marsupial type exhibits the economy of nature under novel and very interesting arrangements. . . . Australia is the great head-quarters of the marsupial tribe." ”

“ Among the characters which serve to distinguish the marsupials, there are two to which I have already called attention in describing the kangaroo; namely, the marsupial bones and the inflected angle of the lower jaw.
Every mammal which has marsupial bones has the angle of its jaw inflected, or else has no angle to its jaw at all; while every animal which has both marsupial bones and an inflected jaw-angle possesses also those special characters of the reproductive system which distinguish the marsupials from all other mammals. ”

“ Mammals belonging to quite different Orders show traces more or less marked of a marsupium. In young Dogs the teats are borne upon an area where the skin is thinner, the covering of hair less dense than elsewhere—all points of resemblance to the inside of the pouch of a Marsupial; in addition to this there are traces of the sphincter marsupii muscle. In other Carnivora there are similar vestiges. In Lemur catta a more complete rudiment of a marsupial pouch is to be met with. ”

“ These are hence called Marsupials. They are for the most part confined to Australasia, though a few occur in America; and are decidedly inferior in rank to the ordinary mammals. Thirdly, those in which there is a bird-like bill, and also certain bird-like or reptilian peculiarities of skeleton and of the alimentary canal. These are the Monotremes, represented by a very few species in Australia and New Guinea.
In geological history, so far as the facts are at present known, the second group, that of the Marsupials, antedated the others by a vast lapse of time. ”

“ The first definite proof of the occurrence of a pouch in any mammal not a Marsupial or a Monotreme was made by Malkmus, who found this structure in a Sheep. It seems, however, that the structures found in the higher mammals are not always comparable to the marsupium of the Marsupials, but sometimes to the mammary pouch of the Monotreme. That the Marsupials are a side line, and not involved in the ancestry of the Eutheria, is an opinion which is at present widely held. ”

“ For of course in the kingdom of science the last shall be first, and the first last; it is the oldest families that are accounted the worst, while the best families mean always the newest. Now, the earliest mammals to appear on earth were creatures of distinctly marsupial type. As long ago as the time when the red marl of Devonshire and the blue lias of Lyme Regis were laid down on the bed of the muddy sea that once covered the surface of Dorset and the English Channel, a little creature like the kangaroo rats of Southern Australia lived among the plains of what is now the south of England. ”

“ In standard works on natural history the animals under consideration are classed as mammiferous Didelphæ. They are brought forth in an imperfect state, and during their transitional condition are suckled in a pouch supported by bones called marsupial, which are attached by their extremities to the pelvis, and serve to support the marsupium, whence the animals provided with these provisions for bringing up their progeny are called Marsupial Mammals. The Opossum, Kangaroo, and Ornithorhynchus are existing representatives of this group. ”

“ The monotremes or egg-laying types of mammals such as the duck-bill and spiny anteaters which now inhabit Australia are almost unknown as fossils. Marsupials, the next higher living group, which includes the opossum and kangaroo, appeared at the end of Cretaceous time along with the placentals or higher mammals which dominate the history of the Cenozoic era. Nevertheless, there are a few teeth and jaws from rocks of Triassic and Jurassic age to indicate that small mammals, from the size of mice to slightly larger than rats, existed throughout most of the Age of Reptiles. ”

“ Many of the early mammals showed characters now found in the marsupials, the order to which the Kangaroo and Opossum belong, members of which are found in rocks of the Secondary Era, and are the only representatives of the mammalia in that age. Some of the early Eocene mammalia are either marsupials, or closely related to them. In the Oligocene we find the mammalian life becoming more varied, and branching out into the various groups we know to-day ”

“ Here, shut off from the severe competition experienced by the animals of northern lands, marsupials were modified so that they were adapted for life in almost every realm utilized by the higher mammals of other countries. Thus there are herbivorous, carnivorous, and insectivorous marsupials. Owing, probably, to the advent of Bats—true flying mammals—at, possibly, a comparatively early time, the marsupial was beaten in the air, and so a true flying form was not evolved, though the so-called "Flying Phalanger" is some distance on the way. ”

“ The order of living marsupials presents remarkable diversity of structure and habits, containing herbivorous, insectivorous, and carnivorous species; yet we find all these traits combined in one and the same species, the opossum. It is probable that, by adaptation to similar modes of life, the marsupials have developed groups parallel to those of the placental mammals. However, it is certain the Quadrumana seem represented by the Phalangers, the Carnivora by the Dasyuri, Insectivora by the Phascogales, Ruminantia by the kangaroos, and Edentata by the Monotremes. ”

“ This pair of little pits may be regarded as the beginning of the bilateral pocket so largely developed in some marsupials. If we can imagine that these depressions have become so deep as to envelop not only the nose of the young, but also its whole body, we can understand the evolution of a marsupial from something lower. ”

“ Mammalia have been found, as already stated, as far back as the Trias formation, in Europe in the United States and in South Africa, all being very small, and belonging either to the Marsupial order, or to some still lower and more generalised type, out of which both Marsupials and Insectivora were developed. ”

“ Hence, while the old-fashioned marsupials continued to survive and to evolve slowly along their own lines in their own restricted southern world, their collateral descendants in Europe and Asia and America or elsewhere went on progressing into far higher, stronger, and better adapted forms—the great central mammalian fauna. ”

“ IT remains now to consider the highest group of the animal kingdom, the class Mammalia, which includes man. Of the existence of this class before the Trias we have no evidence, either in this country or in the Old World, and it is a significant fact that, at essentially the same horizon in each hemisphere, similar low forms of mammals make their appearance. Although only a few incomplete specimens have been discovered, they are characteristic and well preserved, and all are apparently Marsupials, the lowest mammalian group which we know in this country, living or fossil. ”

“ The marsupials are a group of more primitive structure and greater antiquity than any which we have yet considered, so primitive, indeed, that they are referred to a separate infraclass, the Didelphia or Metatheria. ”

“ Why have marsupials in Australia followed after other marsupials, and edentata in South America followed after other edentata, with such remarkable regularity, unless the bond which unites present with past ages be the well-known, the only known, and the only imaginable bond of physical generation? ”

“ Fig. 109.—Newborn young of Kangaroo.
It is very interesting to observe how, in Australia, where the Marsupials have been free from the competition of other mammals, they have evolved along many of the same general lines as the higher group. We have indeed no marsupial whales, bats, or seals, but there is a mole, very similar in its appearance and habits to our European species, and a carnivorous type which closely resembles a wolf or jackal; again we have bandicoots, occupying the same place in nature as our rabbits and other rodents ”