Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Chordate


Related Topics

In the News (Thu 21 Mar 19)

  
  Cambrian Primitive Chordate Fossil
Chordate origins are not fully understood though there are several theories.
The Chordates are distinguished most notably by a notochord, a semi-flexible rod running along the length of the animal.
All chordates have a notochord at some stage in their lives, but in some the notochord is lost in the adult, whereas in others such as the vertebrates, the notochord is present in the embryo but is later largely replaced and surrounded by the vertebra, or backbone.
www.fossilmuseum.net /Cambrian-Explosion/Chordate/Chordate.htm   (0 words)

  
 Chordate Summary
Vertebrates differ greatly from other chordates in size and activity level, and the evolution of their distinctive characteristics is largely correlated with this difference.
Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates.
They are united by having, at some time in their life, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a muscular tail extending past the anus.
www.bookrags.com /Chordate   (0 words)

  
 chordate
The cladists are claiming the present evolutionary scheme is wrong and that their method is a superior indicator of phylogenetic relationships among the chordates.
The most primitive of the chordates evident in the fossil record are the jawless Ostracoderms.
The next chordates to evolve were true tetrapods and thus were considered Amphibians.
io.uwinnipeg.ca /~simmons/1116/chordate.htm   (0 words)

  
  Duffy: Chordate Origins
Indeed, Garstang (1928) based his theory of a paedomorphic origin solely on the embryology of the extant chordates, and postulated that an organism similar to a urochordate or cephalochordate larva could have acquired sexually maturity without metamorphosing, thus providing a spring-board for the evolution of chordates and vertebrates.
Chordate origin theories based on fossil evidence also exist, such as that of R.P.S. Jefferies (1986), who purports that a fossil group called the calcichordates are basal chordates.
With various interpretations and reinterpretations, it is possible that a general concensus for chordate origins may never be reached, but it is certain that the continued search will provide fuel for much future debate (and papers in Nature!).
www.biology.ualberta.ca /courses.hp/biol606/OldLecs/Lecture2K.08.Duffy.html   (971 words)

  
  Chordata   (Site not responding. Last check: )
Chordates are well represented in marine, freshwater and terrestrial habitats from the Equator to the high northern and southern latitudes.
The notochord is an elongate, rod-like, skeletal structure dorsal to the gut tube and ventral to the nerve cord.
In many of the non-vertebrate chordates, such as tunicates and cephalochordates, the clefts and arches are elaborated as straining devices concerned with capture of small food particles from water.
tolweb.org /tree?group=Chordata   (1676 words)

  
  Chordate - MSN Encarta
Chordate, common name for animals of the phylum Chordata, which includes vertebrates as well as some invertebrates that possess, at least some time in their lives, a stiff rod called a notochord lying above the gut and beneath a single, hollow nerve cord.
The closest relatives of the chordates, the acorn worms of the phylum Hemichordata, are sometimes treated as a chordate group but show only a trace of a dorsal nerve cord and a structure vaguely resembling a notochord.
In both hemichordates and lower chordates the pharynx with its gill slits forms a complex structure that strains food particles from water.
uk.encarta.msn.com /encyclopedia_761558750/Chordate.html   (386 words)

  
 Reference.com/Encyclopedia/Chordate
Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates.
They are united by having, at some time in their life, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a muscular tail extending past the anus.
Chordates all have:(1)a notochord atleast at one point in their life(2)a tail that extends farther than their anus(3) and a backbone.
www.reference.com /browse/wiki/Chordate   (321 words)

  
 Encyclopedia: Chordate   (Site not responding. Last check: )
Category: Chordates Classes Ascidiacea Thaliacea Appendicularia Urochordata (sometimes known as tunicata and commonly called urochordates, tunicates or sea squirts) is the subphylum of saclike filter feeders with input and output siphons.
The chordate nerve cord is hollow, with pairs of nerves branching from it at intervals and running to the muscles.
This is apparently a chordate, judging from the shape, fins, and the presence of a notochord and myotomes (which I can't really see in the picture, so I'm going by the article).
www.nationmaster.com /encyclopedia/Chordate   (2526 words)

  
 Morphology of the Chordata   (Site not responding. Last check: )
All chordates have a notochord at some stage in their lives, but in some (such as tunicates) the notochord is lost in the adult, whereas in others (such as the vertebrates) the notochord is present in the embryo, but in later stages is largely replaced and surrounded by the vertebrae, or backbones.
The chordate nerve cord is hollow, with pairs of nerves branching from it at intervals and running to the muscles.
Lastly, all chordates have a post-anal tail, or extension of the notochord and nerve cord past the anus.
www.ucmp.berkeley.edu /chordata/chordatamm.html   (363 words)

  
 Search Results for chordate - Encyclopædia Britannica
The chordate notochord is a stiff rod with a turgid core and fibrous sheath.
Chordates originated sometime earlier than 590 million years ago; that is, they predate the fossil record.
Chordates are capable of locomotion by means of muscular movements at some stage in life.
www.britannica.com /search?miid=1129920&query=chordate   (334 words)

  
 Highbeam Encyclopedia - Search Results for Chordate
All chordates, at some time in their life cycle, possess a dorsal supporting rod (notochord), gill slits, and a...
Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals.
notochord In chordates, such as acorn worms, and the early embryonic stages of vertebrates, the flexible, primitive backbone; in mature vertebrates it is replaced by the spine.
www.encyclopedia.com /SearchResults.aspx?Q=Chordate   (710 words)

  
 BioG 105/106 | Autotutorial Introductory Biology
The chordate nerve cord is positioned dorsal to the gut tube, while the nerve cord of most non-chordates is found ventral to the digestive tract.
All chordates possess the four trademarks of the phylum: a notochord; a dorsal, hollow nerve cord; pharyngeal slits; and a muscular, postanal tail.
The most obvious resemblance of hemichordates to chordates is their possession of pharyngeal slits (and perhaps a short dorsal nerve cord) which are found in all chordates but nowhere else in the animal kingdom.
instruct1.cit.cornell.edu /courses/biog105/labs/deuts/chordates.html   (1578 words)

  
 Biology of chordates video guide shows vertebrate evolution.
All chordates possess four characteristics that define the phylum, although in most species, these characteristics can only be seen during a relatively small portion of the life cycle (and this is often an embryonic or larval stage, when the animal is difficult to observe).
A popular hypothesis regarding chordate evolution suggests that an ancestral tunicate gave rise to the higher chordate groups through an evolutionary process (paedomorphosis) whereby structural and swimming characteristics of the tunicate tadpole larva were retained into adulthood.
Living chordates, such as sea squirts, larvaceans, lancelets, hagfish, sharks, bony fish, salamanders, turtles, snakes, birds, and mammals all reflect descent from a common ancestor with the four chordate characteristics: notochord, dorsal nerve cord, post anal tail and pharyngeal gill.
ebiomedia.com /prod/BOchordates.html   (1592 words)

  
 Search Results for "Chordate"
...A chordate marine animal of the subphylum Urochordata; a tunicate.
A member of an extinct group of small primitive fishlike chordates, preserved primarily in the form of their conelike teeth.
Most chordates are vertebrates (animals with backbones), but the phylum also includes...
www.bartleby.com /cgi-bin/texis/webinator/sitesearch?FILTER=&query=Chordate   (282 words)

  
 CHORDATE   (Site not responding. Last check: )
Chordates include the vertebrates, together with several closely related invertebrates.
They are united by having, at some stage in their life, a notochord, a hollow dorsal nerve cord, pharyngeal slits, a tail extending past the anus, and bands of muscles that go around the body.
It is licensed under the GNU free documentation license.
www.yotor.org /wiki/en/ch/Chordate.htm   (158 words)

  
 chordate
An animal with a notochord (a cartilaginous rod that extends the length of the body), dorsal hollow nerve cord (a fluid-filled tube that runs the length of the body), gill slits or pouches, and a tail at some stage in its life cycle.
Chordates (the group name is Chordata) include mammals, birds, reptiles, amphibians, and fishes–; known collectively as vertebrates –; and lancelets, acorn worms, and sea squirts (tunicates).
It has a hollow dorsal nervous system, the tail is supported by a notochord, and though the gut is not well developed (the larva does not feed) it usually has a pair of gill slits.
www.daviddarling.info /encyclopedia/C/chordate.html   (202 words)

  
 A possible Early Cambrian chordate
THE first chordate recorded from the Early Cambrian is the ceph-alochordate Yunnanozoon lividum from the 525 million-year-old Chengjiang fauna.
Chordate features of Yunnanozoon are a noto-chord and an expanded filter-feeding pharynx with an endostyle.
Our identification predicts that other chordate clades (tunicates and craniates) had evolved by the Late Atdabanian, in the main burst of the Cambrian Explosion.
www.nature.com /doifinder/10.1038%2F377720a0   (0 words)

  
 The Shape of Life . Chordates | PBS
Chordates have their skeletons on the inside, a design that allows for growth without the need for molting.
Of the approximately 50,000 living chordates, 97% are vertebrates -- animals whose skeletons include a backbone.
Another chordate feature is a hollow nerve structure called a dorsal nerve cord that in most members becomes the spinal cord and brain.
www.pbs.org /kcet/shapeoflife/animals/chordates.html   (233 words)

  
 Chordate - Search Results - ninemsn Encarta
Chordate, common name for animals of the phylum Chordata, which includes vertebrates as well as some invertebrates that possess, at least some time...
Vertebrate, any chordate animal possessing a segmented spinal column in the adult stage.
The acorn worm has features that suggest a relationship to the chordate lineage.
au.encarta.msn.com /Chordate.html   (110 words)

  
 chordate - Search Results - MSN Encarta
Chordate, common name for animals of the phylum Chordata, which includes vertebrates as well as some invertebrates that possess, at least for some...
One phylum of animals, the chordates, has been more intensively studied than has any other, because it comprises nearly all the world’s largest and...
Balanoglossus, genus of marine, wormlike animals of great zoological interest as a possible evolutionary link between invertebrates and vertebrates...
encarta.msn.com /chordate.html   (128 words)

  
 The Notochords Sing! Funny, educational science by Dr. Chordate
Chordate: Parts Is Parts - More Songs of Science at Apple iTunes, Dr Chordate: Songs of Biology, Plus.
Chordate: Parts Is Parts - More Songs of Science at PayPlay.fm, or any of 50 or so other sites.
A lot of folks have asked what Dr Chordate looks like (well, at least 2, anyway), so I have added a page of Dr. Chordate in Action which will have one or more recent photos for your viewing pleasure.
www.tranquility.net /~scimusic   (399 words)

  
 Genome Biology | Full text | Seeing chordate evolution through the Ciona genome sequence
Kovalevsky has lately observed that the larvae of ascidians are related to the Vertebrata, in their manner of development, in the relative position of the nervous system, and in possessing a structure closely like the chorda dorsalis of vertebrate animals;...
In 1866, Kovalevsky recognized that this 'gilt-rimmed vase' (see Figure 1a) and its relatives each developed from a beautiful larva that was obviously a chordate and a cousin of the vertebrates.
Chordates, like echinoderms and hemichordates, are deuterostomes, a division of animals that are distinguished from other animals (protostomes) by the development of the embryonic blastopore into the anus rather than the mouth.
genomebiology.com /2003/4/3/208   (2634 words)

  
 Vox Magazine - Dr. Chordate's lyrical experiment   (Site not responding. Last check: )
As Dr. Chordate, Moran, 55, writes and records educational songs such as “Why You Look Like Your Father” and “The Ballad of Sir Isaac Newton & the Three Laws of Motion,” using humor and his knowledge of the biological and physical sciences.
Chordate originals stimulate listeners’ brains and teach a little science.
Chordate: Parts is Parts, More Songs of Science are available for sale at his Web site and from cdbaby.com.
www.voxmagazine.com /stories/2006/03/16/dr-chordates-lyrical-experiment   (740 words)

  
 Facts about topic: (Chordate)   (Site not responding. Last check: )
Chordates (phylum Chordata) include the vertebrate (Animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium) s, together with several closely related invertebrate (Any animal lacking a backbone or notochord; the term is not used as a scientific classification) s.
The extant groups of chordates are related as shown in the phylogenetic tree (additional info and facts about phylogenetic tree), below.
Note that snakes are considered tetrapods because they are descended from ancestors who had a full complement of limbs.
www.absoluteastronomy.com /encyclopedia/c/ch/chordate.htm   (459 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.