Posts tagged teeth.
Here’s a cool fact about sea otters and purple sea urchins I learned today: Sometimes, otters eat so many purple urchins that their teeth and bones become permanently stained!
Of course, anyone who has ever eaten red beets and gone to the bathroom later should not be surprised at all by this.
But about that purple tooth buildup … he really otter see a dentist.
omg joe punned
The bones of your middle ear were once part of a mammalian ancestor’s jaw.
The lower jaws of modern mammals have just one bone: the tooth-bearing dentary. Reptiles, by contrast, also sport smaller bones where the jaw meets the skull. As mammals evolved, the smaller, post-dentary bones shrank to form the tiny bones of the middle ear.
(Clade from Berkeley’s Understanding Evolution page)
a child’s skull before losing baby teeth.
New Rat Without Molars Discovered
by Stephanie Pappas
A newly discovered rat in Indonesia doesn’t have any molars, making it the only known rodent in the world without back teeth.
The long-snouted fuzzball has been dubbed Paucidentomys vermidax. “Paucidentomys” translates roughly to “few-toothed mouse,” while “vermidax” means “worm devourer” — a reference to the new species’ diet.
“When we caught the animal, we were in the forest, and we knew right away that it was something different,” said Jacob Esselstyn, a postdoctoral researcher in biology at McMaster University in Ontario, Canada. “But we couldn’t see inside of its mouth, so had no idea of the unusual lack of teeth.”…
(read more: Live Science) (image: T- Kevin Rowe, B - David Paul)
Evolution of the dental arcade. You can see the reduction in teeth size and the change from straight rows of teeth in P. troglodytes to a curved parabolic arc in H. sapiens.
this seal, lobodon carcinophagus, is called a crab-eating seal, but its main diet consists of krill, which it filters out of the water through its complexly cusped teeth.
Upper: Lateral view of the permanent teeth
Lower: Lateral view of the deciduous teeth [also known as milk teeth or baby teeth]
The permanent teeth consist of 32 teeth of four different types. There are 16 teeth on each jaw, and each jaw has 4 incisors, 2 canines, 4 premolars, and 6 molars (this includes the wisdom teeth, which are shown here)
The smaller mouth of the child only accommodates 20 teeth of three different types. There are 10 teeth on each jaw, and each jaw has 4 incisors, 2 canines, and 4 primary molars.
Atlas and Text-Book of Dentistry. Gustav Preiswerk, translated by George W. Warren, 1906