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Subphyla
In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum. The taxonomic rank of " subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used the rank of subphylum, for instance monocotyledons as a subphylum of phylum Angiospermae and vertebrates as a subphylum of phylum Chordata. Taxonomic rank Subphylum is: #subordinate to the phylum #superordinate to the infraphylum, which is in turn superordinate to parvphylum. Where convenient, subphyla in turn can be divided into infraphyla; in turn such an infraphylum also would be superordinate to any classes or superclasses in the hierarchy. Examples Not all fauna phyla are divided into subphyla. Those that are include: *Arthropoda: divided into subphyla Trilobitomorpha, Chelicerata, Myriapoda, and Pancrustacea *Brachiopoda: divided into subphyla Linguliformea, Craniformea and Rhynchonelliformea *Chordata: divided into Tuni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachiopoda
Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major categories are traditionally recognized, articulate and inarticulate brachiopods. The word "articulate" is used to describe the tooth-and-groove structures of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic skeletal feature, by which the two main groups can be readily distinguished as fossils. Articulate brachiopods have toothed hinges and simple, vertically oriented opening and closing muscles. Conversely, inarticulate brachiopods have weak, untoothed hinges and a more complex system of vertical and oblique (diagonal) muscles used to keep the two valves aligned. In many brachio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subphyla
In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum. The taxonomic rank of " subdivision" in fungi and plant taxonomy is equivalent to "subphylum" in zoological taxonomy. Some plant taxonomists have also used the rank of subphylum, for instance monocotyledons as a subphylum of phylum Angiospermae and vertebrates as a subphylum of phylum Chordata. Taxonomic rank Subphylum is: #subordinate to the phylum #superordinate to the infraphylum, which is in turn superordinate to parvphylum. Where convenient, subphyla in turn can be divided into infraphyla; in turn such an infraphylum also would be superordinate to any classes or superclasses in the hierarchy. Examples Not all fauna phyla are divided into subphyla. Those that are include: *Arthropoda: divided into subphyla Trilobitomorpha, Chelicerata, Myriapoda, and Pancrustacea *Brachiopoda: divided into subphyla Linguliformea, Craniformea and Rhynchonelliformea *Chordata: divided into Tuni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chordata
A chordate ( ) is a bilaterian animal belonging to the phylum Chordata ( ). All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics (Apomorphy and synapomorphy, synapomorphies) that distinguish them from other Taxon, taxa. These five synapomorphies are a notochord, a neural tube, hollow dorsal nerve cord, an endostyle or thyroid, pharyngeal slits, and a post-anus, anal tail. In addition to the morphological characteristics used to define chordates, analysis of genome sequences has identified two conserved signature indels (CSIs) in their proteins: cyclophilin-like protein and inner mitochondrial membrane protease ATP23, which are exclusively shared by all vertebrates, tunicates and cephalochordates. These CSIs provide molecular means to reliably distinguish chordates from all other animals. Chordates are divided into three phylum, subphyla: Vertebrata (fish, amphibians, reptiles, birds and mammals), whose notochor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metamerism (biology), metameric) Segmentation (biology), segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species. Haemolymph is the analogue of blood for most arthropods. An arthropod has an open circulatory system, with a body cavity called a haemocoel through which haemolymph circulates to the interior Organ (anatomy), organs. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. They have ladder-like nervous systems, with paired Anatomical terms of location#Dorsal and ventral, ventral Ventral nerve cord, nerve cord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoological Nomenclature
The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its formal author, the International Commission on Zoological Nomenclature (which shares the acronym "ICZN"). The rules principally regulate: * How names are correctly established in the frame of binominal nomenclature * How to determine whether a given name is available * Which available name must be used in case of name conflicts ( valid name) * How scientific literature must cite names Zoological nomenclature is independent of other systems of nomenclature, for example botanical nomenclature. This implies that animals can have the same generic names as plants (e.g. there is a genus '' Abronia'' in both animals and plants). The rules and recommendations have one fundamental aim: to provide the maximum universality and continuity in the naming of all anim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford University Press
Oxford University Press (OUP) is the publishing house of the University of Oxford. It is the largest university press in the world. Its first book was printed in Oxford in 1478, with the Press officially granted the legal right to print books by decree in 1586. It is the second-oldest university press after Cambridge University Press, which was founded in 1534. It is a department of the University of Oxford. It is governed by a group of 15 academics, the Delegates of the Press, appointed by the Vice Chancellor, vice-chancellor of the University of Oxford. The Delegates of the Press are led by the Secretary to the Delegates, who serves as OUP's chief executive and as its major representative on other university bodies. Oxford University Press has had a similar governance structure since the 17th century. The press is located on Walton Street, Oxford, Walton Street, Oxford, opposite Somerville College, Oxford, Somerville College, in the inner suburb of Jericho, Oxford, Jericho. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agnatha
Agnatha (; ) or jawless fish is a paraphyletic infraphylum of animals in the subphylum Vertebrata of the phylum Chordata, characterized by the lack of jaws. The group consists of both extant taxon, living (Cyclostomi, cyclostomes such as hagfishes and lampreys) and Extinction, extinct clades (e.g. conodonts and Cephalaspidomorphi, cephalaspidomorphs, among others). They are sister taxon, sister to vertebrates with jaws known as gnathostomes, who evolution, evolved from jawless ancestors during the early Silurian by developing folding joint, articulations in the first pairs of gill arches. Sequencing, Molecular data, both from rRNA and from mtDNA as well as Embryology, embryological data, strongly supports the hypothesis that both groups of living agnathans, hagfishes and lampreys, are more closely related to each other than to Gnathostomata, jawed fish, forming the Class (biology), superclass Cyclostomi. The oldest fossil agnathans appeared in the Cambrian. Living jawless fish c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnathostomata
Gnathostomata (; from Ancient Greek: (') 'jaw' + (') 'mouth') are jawed vertebrates. Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all extant vertebrates, including all living bony fishes (both ray-finned and lobe-finned, including their terrestrial tetrapod relatives) and cartilaginous fishes, as well as extinct prehistoric fish such as placoderms and acanthodians. Most gnathostomes have retained ancestral traits like true teeth, a stomach, and paired appendages ( pectoral and pelvic fins, limbs, wings, etc.). Other traits are elastin, horizontal semicircular canal of the inner ear, myelinated neurons, and an adaptive immune system which has discrete secondary lymphoid organs (spleen and thymus) and uses V(D)J recombination to create antigen recognition sites, rather than using genetic recombination in the variable lymphocyte receptor gene. It is now assumed that Gnathostomata evolved from ancestors that already possessed two pairs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycetozoa
Mycetozoa is a polyphyletic grouping of slime molds. It was originally thought to be a monophyletic clade, but in 2010 it was discovered that protostelia are a polyphyletic group within Conosa. Classification It can be divided into dictyostelid, myxogastrid, and protostelid groups. The mycetozoan groups all fit into the unikont supergroup Amoebozoa, whereas most other slime molds fit into various bikont groups ( fonticulids are opisthokonts). Utility in research The dictyostelids are used as examples of cell communication and differentiation, and may provide insights into how multicellular organisms develop. '' Physarum polycephalum'' are useful for studying cytoplasmic streaming. They have also been used to study the biochemical events that surround mitosis, since all of the nuclei in a medium-sized plasmodium divide in synchrony. It has been observed that they can find their way through mazes by spreading out and choosing the shortest path, an interesting example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrata
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebrata with some 65,000 species, by far the largest ranked grouping in the phylum Chordata. The vertebrates include mammals, birds, amphibians, and various classes of fish and reptiles. The fish include the jawless Agnatha, and the jawed Gnathostomata. The jawed fish include both the cartilaginous fish and the bony fish. Bony fish include the lobe-finned fish, which gave rise to the tetrapods, the animals with four limbs. Despite their success, vertebrates still only make up less than five percent of all described animal species. The first vertebrates appeared in the Cambrian explosion some 518 million years ago. Jawed vertebrates evolved in the Ordovician, followed by bony fishes in the Devonian. The first amphibians appeared on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lancelet
The lancelets ( ), also known as amphioxi (: amphioxus ), consist of 32 described species of somewhat fish-like benthic filter feeding chordates in the subphylum Cephalochordata, class Leptocardii, and family Branchiostomatidae. Lancelets diverged from other chordates during or prior to the Cambrian period. A number of fossil chordates have been suggested to be closely related to lancelets, including ''Pikaia'' and ''Cathaymyrus'' from the Cambrian and ''Palaeobranchiostoma'' from the Permian, but their close relationship to lancelets has been doubted by other authors. Molecular clock analysis suggests that modern lancelets probably diversified much more recently, during the Cretaceous or Cenozoic. They are of interest to List of authors of names published under the ICZN, Zoologists as lancelets contain many organs and organ systems that are Homology (biology), homologous to those of modern fish. Therefore, they provide a number of examples of possible evolutionary exaptation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunicate
Tunicates are marine invertebrates belonging to the subphylum Tunicata ( ). This grouping is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time called Urochordata, and the term urochordates is still sometimes used for these animals. Despite their simple appearance and very different adult form, their close relationship to the vertebrates is certain. Both groups are chordates, as evidenced by the fact that during their mobile larval stage, tunicates possess a notochord, a hollow dorsal nerve cord, pharyngeal slits, post-anal tail, and an endostyle. They resemble a tadpole. Tunicates are the only chordates that have lost their Myomere, myomeric segmentation, with the possible exception of the seriation of the gill slits. However, Doliolida, doliolids still display segmentation of the muscle bands. Some tunicates live as solitary individuals, but others replicate by budding and be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
