teeth
milhayser | February 11, 2015Greg Laden reports on a hominid fossil "recovered from the seabed near Taiwan" which reveals new levels of dental diversity among proto-humans and may qualify as a new species. Greg says the specimen known as Penghu "is yet another indicator that multiple different hominids lived on the Earth at the same time after the rise of Homo erectus." But why was it located underwater? In another example of what lies beneath, Dr. Dolittle marvels at "an unexpected find and very exciting moment for researchers;" the discovery of small fish and invertebrates thriving below 740 meters of ice near the…
dr. dolittle | January 8, 2013
Image Credit: Stephanie Abramowicz
Image Credit: Stephanie Abramowicz
Researchers have unearthed a fossil of a robin-sized bird (Sulcavis geeorum) from the Cretaceous Period in China that had teeth! This species belonged to a class of birds with teeth (Enantiornithines) that were plentiful in the age of the dinosaurs. However, the teeth of this well-preserved specimen were different. The teeth were sharp and had serrated ridges. The researchers think the ridges observed on the teeth were designed to crack open insects with hard shells, snails or perhaps even crabs. What I also found…
laelaps | May 11, 2010The jaws of C. megalodon as restored by Bashford Dean for the AMNH in 1909. Image from the American Museum Journal.
My early elementary reading school choices often got me into trouble. Every week I would pass over the recommended, grade-appropriate sections for the few shelves containing the books about dinosaurs, sharks, and alligators - if it was big and hard sharp teeth, I wanted to learn about it. The school librarian was not too pleased with this, even calling my parents in on one occasion to insist that I read something fit for younger children, but I just could not get enough of…
laelaps | February 22, 2010A restoration of the giant, durophagous shark Ptychodus, courtesy paleo-artist Matt Celeskey.
The study of prehistoric sharks is no easy task. Specialists in other branches of vertebrate paleontology at least have the reasonable hope of discovering complete skeletons of their subjects; except in instances of exceptional preservation the scientists who study sharks typically only have teeth and a few vertebrae to work with. Still, you can tell a lot about a shark by its teeth, and a new study published in Cretaceous Research suggests that one peculiar form was a shell-crushing giant.
Thanks to…
laelaps | February 15, 2010A reconstruction of Smilodon, photographed at the American Museum of Natural History.
When it comes to animals, encyclopedias often present us with generalized descriptions. Where a creature lives, what color it is, what it eats, and other tidbits of information are listed to distinguish one species from another, but what is lost is an appreciation of variation. Be they genetic, anatomical, or behavioral, variations are grist for natural selection's mill, and if you study any species in detail it becomes apparent that individuals differ considerably over space and through time.
This was true…
edyong | September 7, 2009The natural world is rife with leftovers. Over the course of evolution, body parts that no longer benefit their owners eventually waste, away leaving behind shrivelled and useless anatomical remnants. The human tailbone is one such example. Others include the sightless eyes of cavefish that live in total darkness, the tiny spurs on boas and pythons that hint at the legs of their ancestors, and the withered wings of the Galapagos cormorant, an animal that dispensed with flight on an island bereft of land predators.
Animal genomes contain similar remains. Just like organs, genes also waste…
edyong | April 13, 2009Our teeth are a mystery. The set we grow during late childhood stays with us throughout our lives, biting and chewing thousands of times a day. They can withstand forces of up to 1,000 newtons and yet, the material that coats them - enamel - is little tougher than glass. How does this extraordinarily brittle substance not shatter into pieces every time we crunch a nut or chomp on an apple?
Herzl Chai from Tel Aviv University found the answer, and it's a surprising one. At a microscopic level, our teeth defend against fractures by developing with cracks already built in. These pre-made…
mikethemadbiologist | April 5, 2009A couple of nights ago, I bought some toothpaste. At the risk of veering off into "in my day, we used sandpaper. And we liked it!" territory, there's a ridiculous variety of toothpaste.
If you just consider Crest, there's Cavity Prevention, Multicare Whitening, Multicare Whitening, and Half-Caff Decaff Mocha with a Twist of Lemon. OK, the last one isn't real, but it seems silly.
Why? Because when I look at the active ingredients, all of these different toothpastes have stannous flouride as the only active ingredient--and usually at the same amount (w/v%). So how are all of these…
edyong | March 10, 2009You're looking at the face of a new species of fish and judging by the two fearsome fangs, you'll probably understand how it got its scientific name - Danionella dracula. The teeth do look terrifying but fortunately, their owner is a tiny animal just 15 millimetres long. Ralf Britz from London's Natural History Museum discovered the fanged fish in a small stream in northern Burma, just two years ago. The more he studied them, the more he realised that they are physically extraordinary in many ways.
For a start, those are no ordinary teeth - they are actually just part of the fish's jawbone…
zooillogix | October 23, 2008Still trying to figure out where the dividing line is between my new project, ZooBorns, and Zooillogix, but this definitely spans the two.
Sixteen-month-old Pacific walrus Akituusaq shows off his new set of titanium crowns at his home in Sea Cliffs at the New York Aquarium. "Aki" was fitted with these crowns by Wildlife Conservation Society Global Health Program veterinarians working with a dental consultant to protect his tusks from damage during growth. Aki seems to be adjusting well to his new armor.
zooillogix | February 23, 2008Dentistry under the sea looks a lot less painful but potentially much more dangerous for the hygienist.
Moray and cleaner shrimp. Photo credit to Erwin Kodiat
Sand Diver and Pedersen's cleaner shrimp. Photo credit to Reef Reflections
Fun fact: adorable cleaner shrimp are notable for crawling down people's throats and laying eggs in their chest! Photo credit to Michael Haas.
zooillogix | November 29, 2007
An artist's rendering of what Pseudotribos robustus or a weasel-possum-lizard, might have looked like 165 million years ago
In the November 1st, issue of Nature, a joint American and Chinese research team announced the discovery of a long dead prehistoric mammal with an interesting set of chompers. Although the teeth were very similar in form to other teeth found at the time, they actually were arranged in a "grind-cut" pattern instead of the more common "cut-grind" pattern! Upon realizing what they were looking at, some of the female researchers fainted from embarrassment.
These days,…
laelaps | October 31, 2007
Happy Halloween, everyone! In searching for a somewhat frightening image (I already recently used Prestosuchus and Amphicyon), I recalled this photo of the AMNH Tyrannosaurus rex mount. Most of the photos I have of the reconstruction are of the whole head or body, but I especially like this one for far more subtle reasons; the close-up makes it appear as if the dinosaur is just beginning to open its jaws, my imagination filling in the sound of heavy breaths escaping the cavernous tooth-lined maw.
zooillogix | October 26, 2007According to the Tree of Life project, Promachoteuthis sulcus is known from a single, small (25 mm ML, sex unknown) but distinctive individual from great depths in the south Atlantic Ocean. Now Benny and I are no cephalopodologists, but those chompers look a little different from the typical squid beak which we have come to know and fear.
Those of you looking to find or avoid the aforementioned denture squid should steer clear of here: 36°49'S, 12°17'W off Tristan Da Cunha, south Atlantic Ocean. Captured from WALTHER HERWIG at 1750-2000 m depth (open net).
Kevin Z? PZ? Other…