Hypsodont

After the crown height are low to distinguish mammals hochkronige teeth. Teeth with a high crown are further divided into those with late -closing to root and rootless teeth with it not closing root and unlimited growth. The boundaries between the different forms are fluid.

Brachyodontie

Niederkronige or brachycephalic ( o) donte teeth ( from Ancient Greek βραχύς brachys, short ' and ὀδόντος odontos, teeth ') have well-developed roots, which form early in short-term growth of the teeth. Her crown is completely outside of the tooth socket and is resistant to the roots low. Most mammalian teeth are niederkronig.

Hypsodontie

Hochkronige, hypsodont or hypselodonte teeth ( from Ancient Greek ὕψος Hypsos, height ' or ὑψηλος hypselos, high' and ὀδόντος odontos, teeth ') have roots that close late or not, so that the teeth grow correspondingly long. The conceptual distinction between hypsodont and hypselodont is different and contrary handled so that Álvaro Mones (1982 ) instead use the unambiguous terms protohypsodont and euhypsodont recommends.

As an adaptation to silica-containing foods such as grasses to hochkronige molars have often developed independently in grains and herbivorous mammals. Keep the increased abrasion during mastication longer stood as niederkronige teeth. Hochkronige teeth are completely enveloped in the investment of cement. Due to the varying degrees of wear of cement, dentin and enamel strips are exposed on the crown, remain between which are cement strip (caries and tartar ). The humps and ledges grow strong in the air and can be a complicated groin and snare patterns form with sharp edges melt.

In the back teeth the tooth compartments hochkroniger teeth need lots of space and there is a transformation of the skull. Thus, in artiodactyls and perissodactyls the orbit is shifted to the rear and in rodents, the space requirement is usually at the expense of the posterior nasal capsule and the eye socket.

Protohypsodontie

Protohypsodonte teeth ( from Ancient Greek πρῶτος protos, first ', ὕψος Hypsos, height ' and ὀδόντος odontos, teeth ') have limited growth and their roots close late.

Euhypsodontie

Rootless or euhypsodonte teeth ( from Ancient Greek εὖ eu 'good', ὕψος Hypsos, height ' and ὀδόντος odontos, teeth ') have an unlimited growth and pulp cavity is not limited in its extent by secondary dentin.

Rootless molars are found in lagomorphs, many rodents and some hyraxes. In addition, incisors and canines as the incisors of rodents and lagomorphs, the tusks of elephants and corresponding teeth may be formed in pigs, hippos and walrus as rootless teeth.

The premolars and molars of horses and some artiodactyls are not rootless but hypsylodont. You are mature in their investment and not continue to grow, but the abrasion be pushed accordingly, which leads to an expansion of the maxillary sinus. The pulp cavity is gradually filled with secondary dentine to prevent the opening of the cavum dentis.

Used literature

• Erwin J. Hentschel, Günther H. Wagner: Dictionary of Zoology. 7th edition. Oxford University Press ( Elsevier ), Heidelberg 2004, ISBN 3-8274-1479-2.
• Álvaro Mones: An equivocal nomenclature: What Means hypsodonty? . In: Paleontological Journal. Vol 56, No. 1-2, 1982, ISSN 0031-0220, pp. 107-111.
• Arno Hermann Müller: Textbook of Palaeozoology. Volume III: vertebrates. Part 3: Mammalia. 2nd edition. VEB Gustav Fischer Verlag, Jena, 1989, ISBN 3-334-00223-3.
• Jochen Niethammer, Franz Krapp (Eds. ): Handbook of the Mammals of Europe. Volume 1: Rodents 1 Akademische Verlagsgesellschaft, Wiesbaden 1978, ISBN 3-400-00458-8.
• Dietrich Starck: Textbook of Special Zoology. Volume II: Vertebrates. Part 5: mammals. Gustav Fischer Verlag, Jena / Stuttgart / New York 1995, ISBN 3-334-60453-5.
• Wilfried West Heath, Reinhard Rieger (eds): Systematic Zoology. Part 2: vertebral or cranial animals. Oxford University Press ( Elsevier ), Heidelberg / Berlin 2004, ISBN 3-8274-0307-3.

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