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| | Brain - Wikipedia, the free encyclopedia |
 | | Anatomically, the majority of afferent and efferent nerves (with the exception of cranial nerves) are connected to the spinal cord, which then transfers the signals to the brain. | | | The brain of craniates develops from the anterior section of a single dorsal nerve cord, which later becomes the spinal cord. | | | However, many behaviors, such as simple reflexes and basic locomotion, can be executed under spinal cord control alone. |
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http://en.wikipedia.org/wiki/Brain
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| | VERTEBRATA - LoveToKnow Article on VERTEBRATA |
| | The details of the structure and development of the sense-organs, gill-slits and visceral organs of Craniates are sufficiently discussed in the articles dealing with the separate classes of the group. | | | The hind-brain is closely similar in structure to the spinal cord, and gives rise to all the segmental cranial nerves except the path~eticus and motor oculi. | | | The work of a large number of anatomists has shown that the fundamental morphological characters of the cranium and brain, organs in which the Craniates are most clearly marked off from Cephalochordates, are fundamentally alike throughout the group. |
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http://www.1911encyclopedia.org/V/VE/VERTEBRATA.htm
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| | [No title] |
| | One functional anatomical synapomorphy of craniates is their use of muscles to draw in a feeding and respiratory current of water. | | | Thanks to extensive perichondral ossification of the braincase, investigators have been able to determine the shape of the brain, the inner ear, and the courses of the cranial nerves. | | | It is important to remember that cladograms are only hypotheses about phylogenetic relationships and that the number of characters analyzed to generate such cladograms is large. |
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http://www.bio.umass.edu/biology/bemis/FAOV4/Ch03.doc
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| | Craniata |
| | Oxygenated blood then collects dorsal to the gills and flows anteriorly to the head and posteriorly to the organs and muscles, and back to the heart. | | | As in cephalochordates, the dorsal (sensory) and ventral (motor) spinal nerves are initially separate, but unite in the gnathostomes. | | | As chordates, all craniates develop a notochord, which is primitively large (hagfishes, lampreys), but becomes transitory in most vertebrates and is replaced by elements of the vertebral column, the centra and arcualia. |
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http://tolweb.org/tree?group=Craniata&contgroup=Chordata
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| | Palaeos Vertebrates: Bones: Gill Arches: Meckel's Cartilage |
| | [3] Hagfish have a homologous cranial nerve, including a "mandibular" component; but I have not been able to determine what it innervates. | | | [4] Recall that the heart is a relatively late craniate development. | | | The detailed anatomy and workings of the velum are not yet tackled here. |
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http://www.palaeos.com/Vertebrates/Bones/Gill_Arches/Meckelian.html
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| | Cofrin Center for Biodiversity |
| | During development, the brain and spine form from a a dorsal nerve cord that is supported by a cartilaginous notochord. | | | All craniates are bilaterally symetrical and have a well-developed coelom, a body cavity, derived from the middle layer of embryonic tissues. | | | Gill slits are eventually lost or modified to serve other functions in terrestrial craniates, but they are retained in many aquatic caraniates such as the lampreys. |
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http://www.uwgb.edu/biodiversity/biota/craniata.htm
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| | Lecture 3 - chordate origins |
| | Characters uniting the Chordata (urochordates + cephalochordates + craniates) - these are the characters that everyone in comparative vertebrate anatomy has to memorize! | | | This is a phylogeny based on 18S rDNA from Wada (1998), which suggests that the ancestor of euchordates (Branchiostoma + craniates) was pelagic and had a tadpole-like body morphology throughout its life history. | | | The group (hagfishes + vertebrates) is called Craniata (the craniates). |
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http://www.usm.maine.edu/bio/courses/bio205/bio205_03_vertebrate_orgins.html
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| | GEOL 331 Lectures 35-36: Vertebrate Paleontology |
| | Metamerically arranged endoskeletal elements flanking the spinal cord (aka vertebrae) | | | Primitive condition is several pairs of small gill openings. | | | A problematic group of basal craniates, probably basal vertebrates: Euconodonta |
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http://www.geol.umd.edu/~tholtz/G331/331vertsI.htm
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| | Craniata |
| | Remember all essays, cladograms, etc. are my, an armchair amateur's, opinions.They should not be taken as current scientific theory, although I do try to follow either the currently most widely accepted theory or the theory that makes the most sence to me, and certainly don't take them as fact. | | | These elements serve to protect the brain, and a number of other elements in the head, such as the olfactory, optic, and auditory sensory organs. | | | The diagnostic feature of craniates is a skull, a series of cartilagenous or bony elements around the brain. |
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http://homepage.mac.com/pfhreak/paleontology/clade/C/craniata.html
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| | Palaeos Vertebrates 020.000 Craniata Overview |
| | Generally mention the word "animal" and most people think of a vertebrate animal -- and more particularly a higher vertebrate, especially a mammal. | | | In this view of these taxa, the Petromyzonida are the only surviving lineage of the ancient agnaths (jawless vertebrates), represented only by the parasitical lampreys, "living fossils" which first appeared (in only slightly different form) during the Carboniferous period. | | | The most primitive craniates we know are the living Myxinoidea (hagfishes): eel-like, rather assymmetric creatures with a strong propensity to flood their immediate neighborhood with slime at the slightest provocation. |
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http://www.palaeos.com/Vertebrates/Units/020Craniata/000.html
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| | The Origin and Early Evolution of the Chordata |
| | Amphioxus/Pikaia are our baselines for understanding the origins of craniates | | | Transition from "Protochordates" to craniates marked by a dramatic change in … | | | Contribute to much of the sensory system, including |
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http://www.life.umd.edu/classroom/zool210/jensen/2Lectures/lecture20.html
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| | Vertebrate Evolution - Fish |
| | Some researchers believe that the first craniates developed by neoteny. | | | The agnathans were a group of jawless vertebrates, which included the ostracoderms and heterostracans. | | | We believe that craniates first developed from their ancestors by neoteny. |
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http://www.bio.miami.edu/tom/bil160/bil160goods/19_verts1.html
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| | Gnathostomata |
| | Current phylogenies, however, suggest that the Agnatha are not a clade, and that, among Recent craniates, the gnathostomes are the sister-group of the Hyperoartia (lampreys) only. | | | Gnathostomes have long been placed as the sister-group of the ensemble of the Agnatha, or jawless vertebrates, regarded as a clade. | | | The controversies about gnathostome interrelationships mainly bear on the position of the two major fossil groups, the Placodermi and Acanthodii. |
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http://tolweb.org/tree?group=Gnathostomata&contgroup=Vertebrata
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| | Powell's Books - Comparative anatomy of the vertebrates by Robert K. Carr |
| | Remaining chapters discuss the craniate body with references to outgroups. | | | Presents functional and comparative morphology within a developmental and evolutionary framework, combining data from classical comparative anatomy with current developmental, ecological, and theoretical research. | | | Early chapters cover major organ systems, evolutionary concepts, protochordates, craniates, and early craniate morphogenesis. |
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http://www.powells.com/cgi-bin/biblio?inkey=65-0073038695-1
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| | Highlights in the Evolution of Vertebrates |
| | From a cladistic point of view, the jawed fishes are a paraphyletic group as opposed to a true clade; a pure cladist would not recognised the jawed fishes as a ‘natural’ group at all. | | | “The acquisition of jaws is perhaps the most profound and radical evolutionary step in craniate history, after the development of the head itself. | | | It has been observed that there were as many as ten gill arches in the ostracoderms, or jawless fish. |
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http://www.peripatus.gen.nz/Paleontology/HigEvoVer.html
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| | Grzimeks Animal Life Encyclopedia |
| | Most biologists probably would agree that the consideration of all craniates as fishes would be of little scientific value and would betray the longstanding and widespread conception of a fish. | | | Given that no one characteristic distinguishes all fishes from all other organisms, even the most committed ichthyologist must admit that the superclass Pisces (an assemblage that ineludes all fishes) represents an unnatural or polyphyletic group. | | | In fact, given our scientific understanding of fishes as of 2002, the only measure allowing them to stand together as a natural or monophyletic group requires the inclusion of all other craniates (i.e., amphibians, reptiles, birds, and mammals). |
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http://www.wordtrade.com/science/lifescience/grzimeksanimallifeencyclopedi.htm
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| | Amazon.com: Discovering Fossil Fishes (Henry Holt Reference Book): Books |
| | This gives the reader a good approximation as to what the fossil would look like in life. | | | From their ancient ancestors, the craniates, fishes evolved not once, in a single lineage, but multiple times, filling countless biological niches. | | | Given their long evolutionary history, itis not surprising that so many species of fishes exist today; one new fish species evolving every 18,000 years, or about 55.5 species evolving per one million years. |
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http://www.amazon.com/exec/obidos/tg/detail/-/0805043667?v=glance
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| | Ann B. Butler |
| | Butler, Ann B. 2000d Sensory system evolution at the origin of craniates. |
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http://www.gmu.edu/departments/psychology/homepage/butler.html
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| | SECT. 2. AGNATHA, THE JAWLESS VERTEBRATES |
| | THE BODY WAS FLATTENED DORSOVENTRALLY AND MOST WERE PROBABLY BENTHIC DETRITUS OR PARTICULATE FEEDERS. | | | DIRECT CONNECTION OF PHARYNGEAL SLITS TO OUTSIDE (NO ATRIUM). | | | LITTLE IS KNOWN OF THE SOFT TISSUES OF THE OSTRACODERMS ALTHOUGH SOME HEAD SHIELDS SHOW THE OUTLINE OF THE UNDERLING BRAIN AND CRANIAL NERVES. |
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http://www.ucs.mun.ca/~dunbrack/2210agnatha.html
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