Ceratodontes (original) (raw)
Hornzähne (Ceratodontes) sind Gebilde in der Mundhöhle aus Hornsubstanz, die funktionell als Zähne dienen. Sie entstehen, im Gegensatz zu den Knochenzähnen, durch Verhornung aus dem Epithel der Mundschleimhaut. Sie treten in mehreren Formen auf:
| Property | Value |
|---|---|
| dbo:abstract | Ceratodontes (from Greek: κέρατο, romanized: kérato, lit. 'horn' and Ancient Greek: ὀδόντες, romanized: odóntes, lit. 'teeth') or cornudentes (from Latin: cornū, lit. 'horn' and Latin: dentēs, lit. 'teeth') are structures consisting of keratin, located in the mouth cavity, which functionally serve as teeth. They develop, unlike osseous teeth, through cornification of the epithelium of the oral mucosa. They occur in three forms: 1. * Conical Ceratodontes which occur in Cyclostomata, they lack real teeth or any other form of calcium-based skeleton growth. They are distributed numerously throughout their mouths (which serve to suction) in different sizes and arrangements. Each tooth forms a pointed and hard conical papilla whose base is occupied by vascular pulpa and sits on the oral mucosa. Their innermost layer consists of conical cells, which at their most young inner-end cut off an enamel-like cuticula. 2. * Plate-shaped ceratodontes occur among some mammals, who lost their osseous teeth through the process of evolution, but whose developmental leftovers can still be observed in their jaws during their embryonic state. Platypodes – who lose their osseous teeth upon leaving the breeding burrow – have two such plates located on the chewing surface of each half of their jaw; meaning they possess four such plates in total. The now extinct steller's sea cow had just one such plate on each half of its jaw, which it used for chewing. Baleen whales develop a pair of large, transverse, triangular keratinous plates at their maxilla and palate, which developed out of the cornified epithelium of the palatine raphe. They are referred to as baleen plates. 3. * Rhamphotheca of the jaw edge or keratinised beaks, develop as hard and cutting keratin coatings over the osseous jaw edges. They too represent a secondary cornification of the exodermal oral epithelium. They are present among some reptiles for example anomodonts, turtles and in birds. The older ancestors of these groups all possessed osseous teeth. (en) Hornzähne (Ceratodontes) sind Gebilde in der Mundhöhle aus Hornsubstanz, die funktionell als Zähne dienen. Sie entstehen, im Gegensatz zu den Knochenzähnen, durch Verhornung aus dem Epithel der Mundschleimhaut. Sie treten in mehreren Formen auf: * Konische Hornzähne finden sich bei Rundmäulern. * Plattenförmige Hornzähne treten bei einigen Säugetieren auf, denen die Knochenzähne verloren gegangen sind. Sie finden sich beispielsweise bei Schnabeltieren, Seekühen und Bartenwalen. * Hornscheiden (Rhamphotheca), welche die Kieferknochen überziehen, treten bei Anomodontia, Schildkröten und Vögeln (→ Schnabel) auf. (de) |
| dbo:wikiPageID | 53615612 (xsd:integer) |
| dbo:wikiPageLength | 3360 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 1125019866 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:Epithelium dbr:Mouth dbr:Cornification dbr:Beak dbr:Bird dbr:Bone dbr:Reptile dbr:Cuticle dbr:Oral_mucosa dbr:Anomodont dbr:Mammal dbr:Steller's_sea_cow dbr:Keratin dbr:Papilla_(fish_anatomy) dbr:Baleen_whale dbr:Turtle dbr:Cyclostomata dbr:Evolution dbr:Baleen dbr:Tooth dbr:Pulp_(tooth) dbr:Platypus dbc:Types_of_teeth dbr:Palatine_raphe |
| dbp:wikiPageUsesTemplate | dbt:Lang-grc dbt:Reflist dbt:Short_description |
| dcterms:subject | dbc:Types_of_teeth |
| rdfs:comment | Hornzähne (Ceratodontes) sind Gebilde in der Mundhöhle aus Hornsubstanz, die funktionell als Zähne dienen. Sie entstehen, im Gegensatz zu den Knochenzähnen, durch Verhornung aus dem Epithel der Mundschleimhaut. Sie treten in mehreren Formen auf: (de) Ceratodontes (from Greek: κέρατο, romanized: kérato, lit. 'horn' and Ancient Greek: ὀδόντες, romanized: odóntes, lit. 'teeth') or cornudentes (from Latin: cornū, lit. 'horn' and Latin: dentēs, lit. 'teeth') are structures consisting of keratin, located in the mouth cavity, which functionally serve as teeth. They develop, unlike osseous teeth, through cornification of the epithelium of the oral mucosa. They occur in three forms: (en) |
| rdfs:label | Hornzahn (de) Ceratodontes (en) |
| owl:sameAs | yago-res:Ceratodontes wikidata:Ceratodontes dbpedia-de:Ceratodontes https://global.dbpedia.org/id/n681 |
| prov:wasDerivedFrom | wikipedia-en:Ceratodontes?oldid=1125019866&ns=0 |
| foaf:isPrimaryTopicOf | wikipedia-en:Ceratodontes |
| is dbo:wikiPageWikiLink of | dbr:Steller's_sea_cow dbr:Cyclostomi dbr:Platypus |
| is foaf:primaryTopic of | wikipedia-en:Ceratodontes |