New fossil dolphin identified
University of Otago researchers have formally identified and named a fossil dolphin which they discovered has a unique feeding method.
University of Otago researchers have formally identified and named a fossil dolphin which they discovered has a unique feeding method.
Plants & Animals
Apr 4, 2024
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171
Mario Modesto Mata, a researcher in the Dental Anthropology Group at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), is the lead author of a paper published in The Anatomical Record, on the use ...
Archaeology
Apr 4, 2024
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12
Chattering squirrels, charming coypus, and tail-slapping beavers—along with some other rodents—have orange-brown front teeth. Researchers have published high-resolution images of rodent incisors in ACS Nano, providing ...
Nanomaterials
Apr 17, 2024
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46
Many people assume that horses first came to the Americas when Spanish explorers brought them here about 500 years ago. In fact, recent research has confirmed a European origin for horses associated with humans in the American ...
Evolution
Mar 27, 2024
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24
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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