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Cephalization
Cephalization is an evolutionary trend in which, over many generations, the mouth, sense organs, and nerve ganglia become concentrated at the front end of an animal, producing a head region. This is associated with movement and bilateral symmetry, such that the animal has a definite head end. This led to the formation of a highly sophisticated brain in three groups of animals, namely the arthropods, cephalopod molluscs, and vertebrates. Animals without bilateral symmetry Cnidaria, such as the radially symmetrical Hydrozoa, show some degree of cephalization. The Anthomedusae have a head end with their mouth, photoreceptive cells, and a concentration of neural cells. Bilateria Cephalization is a characteristic feature of the Bilateria, a large group containing the majority of animal phyla. These have the ability to move, using muscles, and a body plan with a front end that encounters stimuli first as the animal moves forwards, and accordingly has evolved to contain many of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California Museum Of Paleontology
The University of California Museum of Paleontology (UCMP) is a paleontology museum located on the campus of the University of California, Berkeley. The museum is within the Valley Life Sciences Building (VLSB), designed by George W. Kelham and completed in 1930. Its collections are primarily intended for research and are, thus, not accessible to the public. A limited number of fossils from the collection is on display in the VLSB. Although located on the Berkeley campus, the museum is the primary locality for storing fossils collected statewide. The original fossils, around which the current collection has grown, were those gathered as part of the California Geological Survey from 1860-1867. Website UCMP was one of the first museums to have its own website in the early 1990s, due to its location within a technology-oriented university with a good Internet connection. The site has been applauded for its use of visually appealing graphics, was nominated for a Webby Award five ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portugal 20140812-DSC01434 (21371237591)
Portugal, officially the Portuguese Republic, In recognized minority languages of Portugal: :* mwl, República Pertuesa is a country located on the Iberian Peninsula, in Southwestern Europe, Southwestern Europe, and whose territory also includes the Macaronesian archipelagos of the Azores and Madeira. It features Cabo da Roca, the westernmost point in continental Europe, its mainland west and south border with the North Atlantic Ocean and in the north and east, the Portugal-Spain border, constitutes the longest uninterrupted border-line in the European Union. Its archipelagos form two Autonomous Regions of Portugal, autonomous regions with their own Local government, regional governments. On the mainland, Alentejo region occupies the biggest area but is one of the least densely populated regions of Europe. Lisbon is the Capital city, capital and List of largest cities in Portugal, largest city by population, being also the main spot for tourists alongside Porto, the Algarve an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian. The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deuterostomia
Deuterostomia (; in Greek) are animals typically characterized by their anus forming before their mouth during embryonic development. The group's sister clade is Protostomia, animals whose digestive tract development is more varied. Some examples of deuterostomes include vertebrates (and thus humans), sea stars, and crinoids. In deuterostomy, the developing embryo's first opening (the blastopore) becomes the anus, while the mouth is formed at a different site later on. This was initially the group's distinguishing characteristic, but deuterostomy has since been discovered among protostomes as well. This group is also known as enterocoelomates, because their coelom develops through enterocoely. The three major clades of deuterostomes are Chordata (e.g. vertebrates), Echinodermata (e.g. starfish), and Hemichordata (e.g. acorn worms). Together with Protostomia and their out-group Xenacoelomorpha, these compose the Bilateria, animals with bilateral symmetry and three germ la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephrozoa
Nephrozoa is a major clade of bilaterians, divided into the protostomes and the deuterostomes, containing almost all animal phyla and over a million extant species. Its sister clade is the Xenacoelomorpha. The Ambulacraria (conventionally deuterostomes) was formerly thought to be sister to the Xenacoelomorpha, forming the Xenambulacraria as basal Deuterostomes, or basal Bilateria invalidating Nephrozoa and Deuterostomes in earlier studies. The coelom, the digestive tract and excretory organs ( nephridia), and nerve cords developed in the Nephrozoa. It has been argued that, because protonephridia are only found in protostomes, they cannot be considered a synapomorphy In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to hav ... of this group. This would make Nephrozoa an improper name, le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neochildia Fusca
''Neochildia'' is a monotypic genus of a dark brown acoel belonging to the family Convolutidae. The only species is ''Neochildia fusca''. The nervous system is composed of an anterior compact brain organized as a layer of neural somata surrounding a central neuropil Neuropil (or "neuropile") is any area in the nervous system composed of mostly unmyelinated axons, dendrites and glial cell processes that forms a synaptically dense region containing a relatively low number of cell bodies. The most prevalent a ... free of cell bodies. References Acoelomorphs {{Xenacoelomorpha-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aurelia Aurita NASA
Aurelia may refer to: People * Version of feminine given name Aurélie * Aurelia (mother of Caesar) * Aurelia gens, a Roman family * Aurelia Browder, American civil rights activist * Astrud Aurelia, American drag queen Science * ''Aurelia'' (cnidarian), genus of jellyfishes in the family Ulmaridae * Aurelia, synonym for chrysalis * Aurelia (crater), a crater on Venus * 419 Aurelia, an asteroid * Aurelia, a hypothetical Earth-sized planet orbiting a red dwarf star Places * Aurelia, medieval Latin name for Orléans * Aurelia, Iowa, a small city in the United States Arts and entertainment * The title character of Giraudoux's play '' The Madwoman of Chaillot'' * ''Aurelia'' (telenovela), a Mexican telenovela * "Aurelia", a hymn tune for "The Church's One Foundation" by Samuel Sebastian Wesley * "Aurélia", an 1855 novella by Gérard de Nerval * "Aurelia", a 1953 single by The Pelicans * "Aurelia", a track from the 2017 album '' AFI'' by AFI Other uses * Via Aurelia, an Ancie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planulozoa
Planulozoa is a clade which includes the Placozoa, Cnidaria (corals and jellyfish) and the Bilateria (all the more complex animals including worms, insects and vertebrates). The designation Planulozoa may be considered a synonym to Parahoxozoa. Within Planulozoa, the Placozoa may be a sister of Cnidaria to the exclusion of Bilateria. The clade excludes basal animals such as the Ctenophora (comb jellies), and Porifera (sponges). Although this clade was sometimes used to specify a clade of Cnidaria and Bilateria to the exclusion of Placozoa (against the original intention of its proposal), this is no longer favoured due to recent data indicating a sister group relationship between Cnidaria and Placozoa. The phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ... indic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Tree
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyhelminthes
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates (having no body cavity), and have no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously. In traditional medicinal texts, Platyhelminthes are divided into Turbellaria, which are mostly non-parasitic animals such as planarians, and three entirely parasitic groups: Cestoda, Trematoda and Monogenea; however, since the turbellarians have since been proven not to be monop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellow Papillae Flatworm (Thysanozoon Nigropapillosum) (cropped)
''Thysanozoon nigropapillosum'' is a species of polyclad flatworms belonging to the family Pseudocerotidae. Some common names include gold-speckled flatworm, marine flatworm, yellow papillae flatworm, yellow-spotted flatworm, and yellow-spotted polyclad flatworm. Description ''Thysanozoon nigropapillosum'' has a long body and broad shape. They grow up to . The dorsal surface is deep black and covered with numerous yellow-tipped papillae varying in size. The ventral surface is dark brown. The outer margin of the body is slightly wavy and bordered in opaque white. They have small, ear-like pseudotentacles in the middle of the anterior end. They swim by propelling themselves through the water with a rhythmic undulating motion of the body. Distribution This species is widespread in the tropical Indo-Pacific. Biology ''Thysanozoon nigropapillosum'' is quite common along the external reef in the shallow sub-tidal zone. It can swim by undulating and rhythmically contracting t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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