Microcavity experiment heads to ISS

The second Swinburne Haileybury International Space Station Experiment (SHINE) launched from Wallops Island, Virginia in the US aboard an Antares rocket at 6.46am (AEST), to make its way to the International Space Station ...

Tongzi hominids are potentially a new human ancestor in Asia

The CENIEH has been participating in a comparative research about human teeth discovered in this Southern China site which has revealed that Tongzi's teeth do not fit the morphological pattern of traditional Homo erectus.

How megalodon's teeth evolved into the 'ultimate cutting tools'

Megalodon, the largest shark that ever lived, is known only from its gigantic bladelike teeth, which can be more than 7 inches long. But these teeth, described by some scientists as the "ultimate cutting tools," took millions ...

Activating tooth regeneration in mice

Most reptiles and fish have multiple sets of teeth during their lifetime. However, most mammals, such as humans, have only one set of replacement teeth and some mammals, like mice, have only a single set with no replacement. ...

Change of teeth causes yo-yo effect in elephants' weight

The weight of elephants living in zoos fluctuates over the course of their adult lives in cycles lasting around a hundred months, researchers at the University of Zurich have found. The fluctuation is linked to the particular ...

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Tooth

Teeth (singular tooth) are small whitish structures found in the jaws (or mouths) of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of tissues of varying density and hardness.

Teeth are among the most distinctive (and long-lasting) features of mammal species. Paleontologists use teeth to identify fossil species and determine their relationships. The shape of the animal's teeth are related to its diet. For example, plant matter is hard to digest, so herbivores have many molars for chewing. Carnivores, on the other hand, need canines to kill prey and to tear meat.

Mammals are diphyodont, meaning that they develop two sets of teeth. In humans, the first set (the "baby," "milk," "primary" or "deciduous" set) normally starts to appear at about six months of age, although some babies are born with one or more visible teeth, known as neonatal teeth. Normal tooth eruption at about six months is known as teething and can be painful.

Some animals develop only one set of teeth (monophyodont) while others develop many sets (polyphyodont). Sharks, for example, grow a new set of teeth every two weeks to replace worn teeth. Rodent incisors grow and wear away continually through gnawing, maintaining relatively constant length. Many rodents such as voles (but not mice) and guinea pigs, as well as rabbits, have continuously growing molars in addition to incisors.

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