Search results
Results From The WOW.Com Content Network
Ptychodus was a large shark, previously estimated at 10 meters (33 feet) long based on extrapolation from teeth. [ 13 ] [ 14 ] The subadult specimen with the largest vertebra showed that it could reach lengths of 4.3–7.07 m (14.1–23.2 ft), so a 10 m (33 ft) length is possible, but more analysis is required for verification.
Helicoprion is an extinct genus of shark-like [1] eugeneodont fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls", which in life were embedded in the lower jaw. As with most extinct cartilaginous fish, the skeleton is mostly unknown.
Any fossils, including fossil shark teeth, are preserved in sedimentary rocks after falling from their mouth. [13] The sediment that the teeth were found in is used to help determine the age of the shark tooth due to the fossilization process. [15] Shark teeth are most commonly found between the Upper Cretaceous and Tertiary periods. [16]
The selected pictures are what we believe to be the best pictures on Wikipedia related to sharks.Any image that is featured or valued on the English Wikipedia, or featured, valued or considered high quality on Wikimedia Commons, and is used in one or more articles within the scope of WikiProject Sharks, automatically qualifies, and may be added below.
Shark teeth are strong and made of enamel. Many sharks have 3 rows of teeth. These teeth are embedded in the gums, not the jaw. [10] Sharks are born with teeth that are constantly being replaced. Teeth are replaced every two weeks, approximately. [10] The shape of the teeth determine the diet of the shark.
The first shark-like chondrichthyans appeared in the oceans 400 million years ago, [1] developing into the crown group of sharks by the Early Jurassic. [2] Listed below are extant species of shark. Sharks are spread across 512 described and 23 undescribed species in eight orders. The families and genera within the orders are listed in ...
today's connections game answers for wednesday, december 11, 2024: 1. utopia: paradise, seventh heaven, shangri-la, xanadu 2. things you shake: hairspray, magic 8 ...
The teeth of the saw typically alternate between large and small. Saw sharks reach a length of up to 5 feet and a weight of 18.7 pounds, with females tending to be slightly larger than males. [4] The body of a longnose saw shark is covered in tiny placoid scales: modified teeth covered in hard enamel. [5]