They occur in vertebrate animals throughout the globe, though varying in abundance in different districts and at different times.
Vertebrate host, Athene noctua, Little Owl; invertebrate host, Culex pipiens.
By a simple modification, the open pit becomes a solid ectodermal ingrowth, just as in Teleostean fishes the hollow medullary tube, or the auditory pit of other vertebrate embryos, is formed at first as a solid cord of cells, which acquires a cavity secondarily.
Non-committal as regards evolution, he vastly broadened the field of vertebrate palaeontology by his descriptions of the extinct fauna of England, of South America (including especially the great edentates revealed by the voyage of the " Beagle "), of Australia (the ancient and modern marsupials) and of New Zealand (the great struthious birds).
The minute gradations observed by Hyatt, Waagen and all invertebrate palaeontologists, in the hard parts (shells) of molluscs, &c., are analogous to the equally minute gradations observed by vertebrate palaeontologists in the hard parts of reptiles and mammals.
Smith Woodward's Outlines of Vertebrate Palaeontology (Cambridge, 1898).
In 1883-1886 Bateson showed by his embryological researches that the Enteropneusta exhibit chordate (vertebrate) affinities in respect of the coelomic, skeletal and nervous systems as well as in regard to the respiratory system, and, further, that the gill-slits are formed upon a plan similar to that of the gillslits of Amphioxus, being subdivided by tongue-bars which depend from the dorsal borders of the slits.
In company with Major St John, R.E., he made a large collection of the vertebrate fauna in a journey from Gwetter to Tehergn in 1872.
A brief summary of the rise of vertebrate palaeontology is found in the address of O.
The size of the animals varies greatly, from forms a few millimetres in length to Gigantorhynchus gigas, which measures from 10 to 65 cms. The adults live in great numbers in the alimentary canal of some vertebrate, usually fish, the larvae are as a rule encysted in the body cavity of some invertebrate, most often an insect or crustacean, more rarely a small fish.
Latreille,2 rightly estimating the value of these differences, though he was not an original worker in the field of vertebrate zoology, proposed to separate Brongniart's Batrachia from the class of Reptilia proper, as a group of equal value, for which he retained the Linnaean name of Amphibia.
These pits are not isolated, but are connected by an ectodermal ridge, which grows in at the margin of the mantle and forms a continuous band somewhat resembling the ectodermal primordium of vertebrate teeth.
This division of the Vertebrata into hot and cold blooded is a curiously retrograde step, only intelligible when we reflect that the excellent entomologist had no real comprehension of vertebrate morphology; but he makes some atonement for the blunder by steadily upholding the class distinctness of the Amphibia.
The great problems involved in the study of geographical distribution must therefore be based mainly upon the other classes, both vertebrate and invertebrate, which, moreover, enjoy less great facilities of locomotion than the birds.
The leading idea of Cuvier, his four embranchemens, was confirmed by the Russo-German naturalist Von Baer (1792-1876), who adopted Cuvier's divisions, speaking of them as the peripheric, the longitudinal, the massive, and the vertebrate types of structure.
In addition, a Trypanosome whose vertebrate host is yet unknown (T.
I thought I might just as well describe my pet in order to know it--order, vertebrate; division, quadruped; class, mammalia; genus, felinus; species, cat; individual, Tabby.
I think she will laugh when I tell her she is a vertebrate, a mammal, a quadruped; and I shall be very sorry to tell her that she belongs to the order Carnivora.
But no vertebrate advance in force took place until comparatively late in the afternoon, and by evening the attacking side, although enjoying a great numerical superiority, had only reached the foot of the hills that lay to the E.
On gaining an entry into the blood of a vertebrate the organisms pass rapidly into the general circulation, and are thus carried all over.
And some, like the bed-bugs, are parasites of vertebrate animals, on whose bodies they live temporarily or permanently, and whose blood they suck.
21), so that its fibres join the anterior faces of the nerve-end cells as in Vertebrates, instead of their posterior faces as in the cephalic eyes of Mollusca and Arthropoda; moreover, the lens is not a cuticular product but a cellular structure, which, again, is a feature of agreement with the Vertebrate FIG.
It has been calculated that about 595 different species of vertebrate animals are recorded or still to be found in Palestine - about 113 being mammals (including a few now extinct), 348 birds (including 30 species peculiar to the country), 91 reptiles and 43 fishes.
Their adaptations to parasitic life in vertebrate animals appear to have involved such modifications of structure and development that their affinities are quite problematical.
34, and in the constitution of its digestive, vascular, respiratory (branchial), excretory, skeletal, nervous and muscular systems it exhibits what appears to be a primordial condition of vertebrate organization, a condition which is, in fact, partly recapitulated in the course of the embryonic stages of craniate vertebrates.
A new edition of it appeared in 1843 under the title of Lehrbuch der Zootomie, of which only the vertebrate section was corrected by himself.
Some of the species of Aviculariidae also appear to be warningly coloured with black or black and red, and their coloration is associated with the urticating nature of their bristles, which makes them highly unpalatable to vertebrate foes.
This line of hypothesis and demonstration is typical of the palaeogeographic methods generally - namely, that vertebrate palaeontologists, impressed by the sudden appearance of extinct forms of continental life, demand land connexion or migration tracts from common centres of origin and dispersal, while the invertebrate palaeontologist alone is able to restore ancient coast-lines and determine the extent and width of these tracts.
No food passes into the hepatic caecum, which has been definitely shown on embryological and physiological grounds to be the simplest persistent form of the vertebrate liver.
The illustrations will be drawn both from vertebrate and invertebrate palaeontology.
Probably most forms possess a resting, attached phase at some period or other, in the invertebrate, if not in the vertebrate host.
That the lower types of vertebrate, such as fish, e.g.
The transmission of the parasites from one vertebrate individual to another is effected, in the great majority of cases,' by a blood-sucking invertebrate, and by this means alone.
confined to the land, but had to do also with those littoral meadows where invertebrate and vertebrate marine animals fed in unlimited numbers.
In other words, the origin, or first appearance of new characters, which is the essence of evolution, is an orderly process so far as the vertebrate and invertebrate palaeontologist observes it.
indifferent, male or female, can be recognized in many cases, often in the vertebrate, but always more sharply differentiated in the invertebrate.
As regards vertebrate zoology, Afghanistan lies on the frontier of three regions, viz.
In dealing with disease-causing forms, the more narrowly the original source of the parasite concerned is defined, the closer do we get to the true vertebrate host or hosts.
Beside the expansion of types which abounded in the Cambrian, vertebrate remains (fishes) are found in the Ordovician.
Finally, the Tylopoda differ not only from other ungulates, but from all other mammals, in the fact that the red corpuscles of the blood, instead of being circular in outline, are oval as in the inferior vertebrate classes.
On the whole, as in the case of vertebrate palaeontology, the pre-Darwinian period of invertebrate palaeontology was one of rather dry systematic description, in which, however, the applications of the science gradually extended to many regions of the world and to all divisions of the kingdom of invertebrates.
is said to produce fully developed gonads, and if kept in aquaria with Tubifex, the number of infected worms steadily increases, a fact pointing to the whole cycle being passed through, without the intermediation of a vertebrate host.
Among American contributions to vertebrate palaeontology, 'the development of Cope's theories is to be found in the volumes of his collected essays, The Origin of the Fittest (New York, 1887), and The Primary Factors of Organic Evolution (Chicago, 1896).
Vertebrate palaeontologists were slow to grasp this principle; while the early speculative phylogenies of the horse of Huxley and Marsh, for example, were mostly displayed monophyletically, or in single lines of descent, it is now recognized that the horses which were placed by Marsh in a single series are really to be ranged in a great number of contemporaneous but separate series, each but partially known, and that the direct phylum which leads to the modern horse has become a matter of far more difficult search.
Cuts, breakages, &c., due to man and other vertebrate animals.
Curiously enough, however, they differ from the cephalic Molluscan eye in the fact that, as in the vertebrate eye, the filaments of the optic nerve penetrate the retina, and are connected with the re surfaces of the nerve-end cells nearer the lens instead of with the opposite end.
Every higher vertebrate animal possesses the power of forming for itself a series of cerebral mechanisms or reasoned conclusions based on its individual experience, in proportion as it has a large cerebrum and has got rid of or has acquired the power of controlling its inherited instincts.
II.-Second Historic Period Invertebrate palaeontology founded by Lamarck, vertebrate palaeontology by Cuvier.
Among the pioneers of this period were the vertebrate zoologists and comparative anatomists Peter Simon Pallas, Pieter Camper and Johann Friedrich Blumenbach.
Cuvier (1769-1832) is famous as the founder of vertebrate palaeontology, and with Alexandre Brongniart (1770-1847) as the author of the first exact contribution to stratigraphic geology.
It appears from comparison of the work in the two great divisions of vertebrate and invertebrate palaeontology made for the first time in this article that in accuracy of observation and in close philosophical analysis of facts the students of invertebrate palaeontology led the way.
Thus both invertebrate and vertebrate palaeontologists have reached independently the conclusion that the evolution of groups is not continuously at a uniform rate, but that there are, especially in the beginnings of new phyla or at the time of acquisition of new organs, sudden variations in the rate of evolution which have been termed variously " rhythmic," "pulsating," " efflorescent," "intermittent " and even " explosive " (Deperet).
TRYPANOSOMES, Or Haemoflagellates, minute Protozoan parasites, characterized by the possession of one or two flagella and an undulating membrane, and specially adapted for life in the blood of a vertebrate.'
I I) and Necrophaga are valuable scavengers from their habit of burying small vertebrate carcases which may serve as food for their larvae.
Huxley questioned the time value of fossils, but recent research has tended to show that identity of species and of mutations is, on the whole, a guide to synchroneity, though the general range of vertebrate and invertebrate life as well as of plant life is generally necessary for the establishment of approximate synchronism.
conserved across vertebrate species.
Actin Filaments At least six different types of actin are synthesized by vertebrate cells.
As the brains of the vertebrate animals form an ascending scale, more and more approaching man's in their arrangement, the fact here finds its explanation, that lower animals perform mental processes corresponding in their nature to our own, though of generally less power and complexity.
Like St Helena, the island does not possess any indigenous vertebrate land fauna.
For a longer or shorter period of their lives ticks are parasitic upon vertebrate animals of various kinds; but although the belief that the bite of certain tropical species is poisonous has long been held by the natives of the countries they infest and has been recorded with corroborative evidence by European authors in books of travel, it is only of recent years that accurate information has been acquired of the part played by these Arachnids in transmitting from one host to another protozoal blood-parasites which cause serious or fatal diseases to man and other animals.
As regards existing forms of life, the limitations of the class are perfectly well defined and easy of recognition; for although certain groups (not, by the way, whales, which, although excluded in popular estimation from the class, are in all essential respects typical mammals) are exceedingly aberrant, and present structural features connecting them with the lower vertebrate classes, yet they are by common consent retained in the class to which they are obviously most nearly affiliated by their preponderating characteristics.
Not so, however, when the extinct forms of vertebrate life are taken into consideration, for there is a group of reptiles from the early part of the Secondary, or Mesozoic period, some of whose members must have been so intimately related to mammals that, were the whole group fully known, it would clearly be impossible to draw a distinction between Mammalia on the one hand and Reptilia on the other.
Considered collectively, mammals, which did not make their appearance on the earth for some time after reptiles had existed, are certainly the highest group of the whole vertebrate sub-kingdom.
The Phoronidea (q.v.) are now associated with Hemichordata (q.v.) in the line of vertebrate ancestry, whilst the Chaetognatha (q.v.) remain in solitary isolation.
He showed that in de Blainville's group there were associated with a number of heterogeneous forms a group of animals characterized by being composed of two layers of cells comparable with the first two layers in the development of vertebrate animals.
In English-speaking countries, and by the majority of German writers, the meaning is now restricted to the study of the action of chemical substances (as apart from foods) on all kinds of animals, from bacteria up to man; it is, in fact, a comparative study of the action of chemical bodies on invertebrate and vertebrate animals.
Vertebrate species in the Irish Vertebrate Red Data Book include whiskered bat, shoveler, pochard and brook lamprey.
clawed frog, one of the model organisms used to study vertebrate development.
He is also studying how germ cell determining mechanisms evolved in vertebrate embryos.
The axolotl is a salamander, and many of the fundamental discoveries in vertebrate embryology came from studies of axolotl embryos.
Testing constraints by artificial selection - direct and correlated responses in butterfly eyespots and in vertebrate digits.
These sections have yielded an unexpectedly diverse vertebrate fauna, in comparison with previous work, with over twenty individual taxa present.
In the 19th and 20th centuries the foreshore has produced robust vertebrate fossils, washed out.
Xenopus laevis - scientific name for the African clawed frog, one of the model organisms used to study vertebrate development.
The effect of humans on other vertebrate species homo sapiens dominate the land today.
mesoderm formation during early vertebrate development.
It was a most remarkable project, and the book instantly became a valuable contribution to vertebrate paleontology.
Broom, D. M. (1999) The welfare of vertebrate pests in relation to their management.
phosphatic nodules with vertebrate teeth and bones occurs at the base of the Coralline Crag.
Extracting species trees from complex gene trees: reconciled trees and vertebrate phylogeny.
A major constituent of the embryonic and young vertebrate skeleton, it is converted largely to bone with maturation.
synthesized by vertebrate cells.
Main research interests: Plio-Pleistocene fossil assemblages and faunal analysis, vertebrate taphonomy, Human evolution and the archeology of the earliest humans.
The jaguar's major prey includes tapirs, deer, monkeys, and capybara, but it will eat almost any vertebrate.
Rather limited small vertebrate remains suggest either a more rapid process or the presence of some sort of structure around the pit.
vertebrate paleontology, moving across the road to the Museum of Zoology.
vertebrate fauna of a Roman town in Pannonia.
A gazetteer of non-human vertebrate remains from caves in the Yorkshire Dales referenced in caving club journals and allied literature.
In the third year, students carry out a research project on a topic of their choosing in marine vertebrate zoology.
2, nch.), growing forwards in the septum between the proboscis-cavity and the collar-cavities, and supported dorsally by the median mesentery of the collar, is the representative of the so-called notochord or stomochord of Balanoglossus; and if the view that this organ is really a notochord is well founded, it may be regarded as the homologue of the anterior end of the Vertebrate notochord.
The Nematode parasites of the Invertebrata are usually immature forms which attain their full development in the body of some vertebrate; but there are a number of species which in the sexually adult condition are peculiar to the Invertebrata.2 The Nematoda contain about as many parasitic species as all the other groups of internal parasites taken together; they are found in almost all the organs of the body, and by their presence, especially when encysted in the tissues and during their migration from one part of the body to another, give rise to various pathological conditions.
After comparing the salamanders and the perenni-branchiate Urodela with the tadpoles and the frogs, and enunciating the law that the more highly any animal is organized the more quickly does it pass through the lower stages, Meckel goes on to say: " From these lowest Vertebrata to the highest, and to the highest forms among these, the comparison between the embryonic conditions of the higher animals and the adult states of the lower can be more completely and thoroughly instituted than if the survey is extended to the Invertebrata, inasmuch as the latter are in many respects constructed upon an altogether too dissimilar type; indeed they often differ from one another far more than the lowest vertebrate does from the highest mammal; yet the following pages will show that the comparison may be also extended to them with interest.
Finally, he saw the spores accumulate within the cells of the salivary glands, and discovered that they actually passed down the salivary ducts and along the grooved hypopharynx into the seat of puncture, thus causing infection in a fresh vertebrate host" (Sambon).
piscis), the common name of that class of vertebrate animals which lives exclusively in water, breathes through gills, and whose limbs take the form of fins (see Ichthyology).
In 1835 Mr Jenyns (afterwards Blomefield) produced as excellent Manual of British Vertebrate Animals, a volume (8vo) executed with great scientific skill, the birds again receiving due attention (pp. 49-286), and the descriptions of the various species being as accurate as they are terse.
- The Trematodes with few exceptions select a vertebrate for their host.
All the members of this order are parasitic on aquatic vertebrates and in rare cases derive their food from a vertebrate host indirectly by means of another invertebrate parasite (e.g.
a X yew), the fluid secreted by the mammary glands of the division of vertebrate animals called Mammalia (see Mammary Gland), and primarily devised for the nourishment of their own young.
The impulse which Darwin gave to vertebrate palaeontology was immediate and unbounded, finding expression especially in the writings of Thomas Henry Huxley (1825-1895) in England, of Jean Albert Gaudry (b.
Unfortunately the vertebrate host of this form is not yet known.
Comparison of the brains of vertebrate animals (see Brain) brings into view the immense difference between the small, smooth brain of a fish or bird and the large and convoluted organ in man.
Main research interests: Plio-Pleistocene fossil assemblages and faunal analysis, Vertebrate taphonomy, Human evolution and the archeology of the earliest humans.
The jaguar 's major prey includes tapirs, deer, monkeys, and capybara, but it will eat almost any vertebrate.
As a result I was inspired to do a PhD in vertebrate paleontology, moving across the road to the Museum of Zoology.
The vertebrate fauna of a Roman town in Pannonia.
We will consider some real data from studies on 2 vertebrate embryos.
Cartilage constitutes a major component of the vertebrate skeleton.
These measures have proved extremely interesting in their applications to analyzing the evolution of the vertebrate genome.
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