Sharks are majestic predators of the deep which have fascinated the lots for time untold. Believe me, I’m hooked on discovering out extra about them. That being stated I’m certainly not a paleontologist, however I’ve finished an honest quantity of analysis to extend my information with reference to discovering shark tooth and answering the 5 W’s (who, what, when, the place and why) about shark tooth. Here are some solutions to many often requested questions concerning shark tooth.
Who do the tooth belong to?
The shark tooth that we’re discovering and amassing are usually not the glowing white tooth you’ll extract from a contemporary dwelling shark, however lovely, shiny black or brown fossilized tooth of their historical ancestors. These tooth are 10,000 years and older and have been hardened with the take a look at of time. As a complete Shark tooth have modified little or no through the years with only a few variations between the totally different geological eras and durations. This makes figuring out the age of the tooth exhausting to do with out information of the place they’d been discovered.
What species did the tooth come from?
Identifying the species of shark explicit tooth got here from could be tedious, however enjoyable. There are dichotomous keys, diagrams, and guides written to assist to find out which tooth belongs to which shark. Some of those fast reference guides may additionally give a tough estimate of age, however it’s simply an estimate. Most are written based mostly on the bodily descriptions of the tooth, however the geological period and/or interval are additionally essential key components in figuring out the particular species and age bracket. Some guides are written for particular search areas for simply this motive. Pictured above are a few the guides I take advantage of to establish tooth in my assortment.
When had been these tooth deposited? How previous are the tooth I discover?
The best option to learn how previous the tooth are is to have a look at the sediment layers the place they had been discovered. Above are the geological sediment maps of Florida. One is the entire state, and the second is of the northeast space the place I focus my looking out. A Google seek for geological sediment map of your space will offer you a map. Note: Sharks themselves are usually not superb indicators of age, as a result of shark evolution as a complete is a gradual course of. Many of the species present in right now’s oceans have been round for tens of millions of years. A greater indicator, if geological maps are usually not accessible, are different fossils fond within the space akin to invertebrates, reptiles, mammals, and birds. But that will require you to search out the opposite fossils, do extra analysis to find out the species in addition to their geological age, after which evaluate the knowledge to the shark fossil report for the realm. Maps are WAY simpler.
Why are there so many fossilized tooth?
The first motive there are such a lot of fossilized tooth is that there are just so many shark tooth, it’s certain to be one of the vital widespread fossils. The motive for all these shark tooth is that sharks have a number of rows of tooth which are continuously being shed to keep up their razor sharp chunk. EACH particular person shark can shed greater than 30,000 tooth in its lifetime. Multiply that 30,000+ tooth by each shark of each species that has ever lived over the previous tens of tens of millions of years, and also you get a staggering quantity of tooth that may be fossilized! Of course, not each tooth is fortunate sufficient to fall to the seafloor and be swiftly buried within the sediment. Those tooth that aren’t fortunate sufficient to be safely ensconced within the sediment might be damaged down by both weathering/abrasion or decay from oxidation and micro organism. This results in the second motive there are such a lot of tooth. The tooth are manufactured from dentin, which is tougher and denser than bone. This permits extra time for the tooth to be protected within the sediment earlier than eroding away. Those tooth that had been sheltered within the sediment slowly turned fossilized over a number of thousand years. These are the tooth which are discovered alongside seashores, in muddy stream beds, and buried inside sedimentary rock.
Why are these tooth black?
Since these tooth are fossilized, they now not seem like tooth freshly extracted from a dwelling shark’s mouth. The colour of the fossilized tooth relies upon the minerals that had been current when the tooth was misplaced. As the tooth would settle into the encircling sediments and permineralization would happen. Water would seep by means of sediments choosing up minerals earlier than flowing over the tooth. Those minerals would then be deposited into the porous construction of the tooth, forming a fossil. Colors of tooth will fluctuate based mostly on the minerals deposited within the tooth and the way they react with hint quantities of oxygen.
Why do we discover largely tooth and never way more of the shark?
Sharks are cartilaginous fish, which means that almost all of their skeleton is cartilage moderately than bone. Cartilage doesn’t mineralize in addition to bone and subsequently breaks down quicker than bone. This makes it a lot tougher for cartilage to fossilize. For this motive, There are only a few fossilized skeletons of sharks, however they do exist. The denser the cartilage was, the extra probably it was to be fossilized. Examples of different shark fossils are the shark’s vertebrae, jaws, dermal ossicles, fin spikes, rostal nodes, and even feces (or coprolites)! Later on this Instructable you will notice what fossilized feces and vertebrae seem like.
Where are fossils discovered?
Fossils could be present in sedimentary rocks or unconsolidated sediments, that are free supplies starting from clay to sand to gravel. In Florida, many of those sediments haven’t been round almost lengthy sufficient to compress into stable (sedimentary) rock, so they’re nonetheless loosely packed. Sea ranges had been a lot greater up to now and what’s now Florida was as soon as lined by sea water. Sharks inhabited these waters and subsequently deposited giant quantities of tooth there. The tooth settled into the ocean backside, and the fossilization course of began. Later, modifications in climates brought about the ocean ranges to fall, exposing the ocean flooring and creating what we now name Florida. The unconsolidated sediments that had been initially deposited on the ocean flooring way back might now be uncovered. Within these uncovered sediments or sedimentary rocks, lay the fossilized shark tooth discovered right now. This sedimentary layer can simply be situated on seashores in most of Florida. Also understanding the place particular sediments are based mostly on age will assist pinpoint the areas to begin exploring. The geological map of Florida is a good reference to find this data.
Where can you discover out extra?
Please take a look at these very nicely written and informative webpages!