characterstics of cephalochordata?
969573
cephalochordates should be examined vis a vis Hemichordates and urochordates. According to older classification these are the the three sub phyla of the phylum chordata.\nThe salient features of cephalochordates is the notochord that extends up to the head region.In chordates the notochord gives rise to the vertebral column and hence it should not extend up to the head region as the first neck vertebra starts from the posterior part of the skull.\nOther important features of cephalochordates include the presence of circulatory system, excretory system formed by flame cells(protonephridia), presence of wheel organ, Hatschek' pits, ciliary mode of feeding, presence of atrial apertures, segmental musculature, presence of epipharyngeal groove and endostyle, ciliated pharynx. Ductless gonads.Two dorsal aortae.
514915
ATLANTIC DEVIL RAY\nOrder - Myliobatiformes\nFamily - Mobulidae\nGenus - Mobula\nSpecies - hypostoma\n(i think this is the one u were asking about)\n\n I didnt know which animal u were exactly asking for. so check out the sites below
755167
This is an excerpt from the referenced website:\n"Recovery of diagnostic ankle bones in the skeletons of primitive protocetids during our field work in Pakistan in 2000 confirmed their derivation from Artiodactyla (the mammalian order including cows, deer, hippos, etc.), and showed convincingly that whales did not originate from mesonychid condylarths as Van Valen hypothesized (and we had expected)."\n\nHope this helps.
152552
I hope that's not a question one of your teachers made. That would be depressing. \nKurdiatcha is right :)\nBut technically speaking, adult sea squirts don't have spinal cords, a lancelet would be a better example. \nWow, I've just done a quick search and there's a wikipedia article (http://en.wikipedia.org/wiki/Tunicata) stating that the notochord is a "primitive spinal cord". Maybe my English vocabulary is wrong, but they seem to have forgotten that primitive chordates have both a notochord and a spinal cord.
191430
Here are two links. The first dscribes it's taxonomical charicteristics, the second link has pictures.\n\nGood Luck.
16277
Here you go:\n\nhttp://www.bsd.sk.ca/~mkozlow/ocean/OctopusandSquid.html#anchor3361022\n\nActually they both have eight ARMS but squids also have 2 tentacles.
845358
What a cool project!  So to answer one of your questions, the crucial distinction among your phyla will be whether or not they're chordates -- which of course includes the vertebrates (but also some invertebrates such as sea squirts and certain worms).  \n\nSo your bipedal wolf (I'm assuming the missing d was a typo, but if "bipeal" is a word from your universe, please let me know) would be phylum chordata, class vertebrata, order mammalia, family canidae, genus canus, species lupus bipedalis (and I'm envisioning something like a cross between Lawrence Talbot and Speaker-to-Animals, without retractible claws).  But that's just off the top of my head.\n\nOne thing I've discussed with my ten-year-old son is the absence of hexapod vertebrates -- e.g. flying horses, winged dragons, etc.  If you were closer, I'd invite you over for coffee and an all-day discussion of where to classify them, and how they evolved.  Since all terrestrial vertebrates have essentially the same structure, it's clear they all shared a common ancestor which makes hexapodal vertebrates, sadly, impossible in our known universe -- so was there a hexapodal (imaginary) marine vertebrate who also scuttled across the floors of silent seas before crawling out of the surf and saying "Hey, the carcharodons can't get me here!  Kewl!"?  ...Which of course suggests all sorts of hexapodal marine vertebrates that shared the same skeletal architecture.  Ooooh, fun.\n\nAnd the final question... so zoology is the study of animals.  There's also cryptozoology, which I've described flippantly as "the study of imaginary animals."  But of course, it's more technically the study of animals that may or may not exist.  So what would we call your zoology, which is the study of animals you've intentionally invented?  Oh, of course, poeiazoology (-poeia, meaing to construct -- as in mythopoeia, the term Tolkien invented to describe the invention of mythologies.)\n\nAnd on that note, elen sila lumen omentielvo!
823692
Have a look here:\nhttp://www.bbc.co.uk/nature/animals/features/287feature2.shtml\n\nAnd here:\nhttp://users.aber.ac.uk/sac5/characteristics.htm
600482
kingdom animalia consits of some phylums. they are\nporifera (sponge)\ncoelentrata (jellyfish)\nplatyhelmintes \nnemathelmintes \nanellida (earthworms, leech)\nmollusca (SHELLS, OYSTERS AND SQUIDS)\narthropoda (crabs, insect, centipide)\nechinodermata (spine skinned animal)\nchordata (animals that have bones)
273418
First off, it's only the number of _cervical_ (neck) vertebrae of mammals that is fixed at 7, not all the other vertebral types. There are exceptions, such as the tree sloths with 6 or 9 vertebrae, and a manatee species with 6, but the number 7 is consistent in most species of mammals, from giraffes (although there was an interesting question about it here) to dwarf shrews. \n\nA recent hypothesis (1999) about the fixed nº of cervical vertebrae is related to evolutionary developmental (evo-devo) aspects. Apparently, in mammals the genes that regulate the development of the skeleton (Hox genes) are also linked to the proliferation of cell lines (which is in turn related to the origin of cancer). Thus, any change in the nº of vertebrae could bring about deletereous (negative) changes in the control of cell multiplication, and would be constrained by natural selection because although the fixed nº of cervical vertebrae is not particularly advantageous, the possibility of tumor development is decidedly disadvantageous.\n\nAnd with respect to canislupus' question: If there is such a constraint, maybe the different number of cervical vertebrae in sloths and manatees gives advantages that offset the potential problems. In the case of sloths, I can easily see that more vertebrae enable greater rotation angle of the head (these animals are very impressive when they move). In the case of manatees, I cannot think of an evident advantage, but then again, I don't know much about manatees.\nSee the article at the first link.\n\n------------\nUpdate: I've checked other sources and it appears that both manatees and sloths share one trait: low basal metabolism. This could allow changes in the regulatory Hox gene without the threat of cancer (see second link)\n------------\nUpdate 2: Canislupus, this is new knowledge for me too. That's why I like Answers :-)
517501
Here you go...\n\nhttp://biog-101-104.bio.cornell.edu/Biog101_104/tutorials/frog.html\nhttp://www.infovisual.info/02/026_en.html
122189
The first were some stem (basal) tetrapods, derived from crossopterygian fishes. Usually they're classified as amphibians, but they looked very different from modern amphibians. They were large (1 m or more), had fin rays on their tails and more than 5 fingers.\nDo a web search for Acanthostega and Ichthyostega.
30468
Normally, it is considered to be Invertebrates the following taxa, though they do not include Hemichordata and Cephalochordata (Which are chordates but not vertebrates):\n\n- Protozoa: unicellular organisms\n- Porifera: sponges\n- Placozoa\n- Orthonectida: (Prev. Mesozoa)\n- Dicyemida: (Prev. Mesozoa)\n- Cnidaria: jellyfish\n- Ctenophora\n- Platyhelmintes: flatworms\n- Nemertea (= Rhynchocoela)\n- Gnathostomulida\n- Rotifera\n- Acanthocephala\n- Micrognathozoa\n- Gastrotrichia\n- Nematoda\n- Nematomorpha\n- Priapula\n- Kinorhyncha (= Echinodera)\n- Loricifera\n- Arthropoda: insects, spiders, crustacea, etc.\n- Annelida\n- Pogonophora\n- Vestimentifera\n- Echiura\n- Sipuncula\n- Mollusca\n- Phorona\n- Ectoprocta (=Bryozoa)\n- Brachiopoda\n- Entoprocta\n- Cycliophora\n- Echinodermata: sea stars, etc.\n\nYou can also include to de list Hemichordata and Cephalochordata.
563676
* Blue\n    * Fin\n    * Humpback\n    * Minke\n    * Orca\n    * Southern Right\n    * Sei\n    * Sperm\n    * Pygmy Right\n    * Beaked
269847
That must be another cephalopod, an ammonite. There's an amazing diversity of these fossil mollusks, with many genera and species. \nPictures:\nhttp://home.tele2.fr/hildoceras/Amaltheus_causses.jpg\nhttp://www.mnhn.fr/expo/agesterre/ammonites.jpg\n\nBut ammonites are grey only because they're fossil (i.e. made of stone), I don't think ammonites were that color while they lived.
935213
I'm not completely sure this is correct, but here is my guess.\n\nhttp://en.wikipedia.org/wiki/Ichthyocladius
178989
You could have looked this up... here are some sites, but I recommend the book Invertebrates by Brusca & Brusca; it has excellent and clear illustrations.\n\nhttp://bugs.bio.usyd.edu.au/Entomology/ExternalMorphology/imagePages/mouth_butterfly.html\nhttp://www.enchantedlearning.com/bgifs/Bflyhead.GIF