Talk:UALR Paleobiology ERSC 3360
|Thread title||Replies||Last modified|
|Carboniferous forrests||0||09:29, 2 May 2011|
|Amber||1||15:43, 28 April 2011|
|Lagerstatten||0||15:42, 28 April 2011|
|Petrification||0||14:58, 3 February 2011|
|Preservation with Mummification||0||13:15, 3 February 2011|
|The Big Freeze! (Petrification via Freezing)||1||04:00, 2 February 2011|
|Permineralization||0||20:48, 30 January 2011|
|...||1||03:36, 29 January 2011|
Last edit: 09:24, 2 May 2011
Carboniferous coal was produced by bark-breaking trees that grew in lowland swamp forests. Types of vegitation in the swamp included; giant club mosses, tree ferns, horsetails and giant trees. Over millions of years, the organic deposits of the plant's debris foarmed coal deposits. This process preserved plant remains very well
This is an example of Carbonization of plant material. This takes place when an organism is buried in layers of sediment.Over time a chemical reaction occurs which turns most of the elements making up the body of the organism to gas. What is left behind is a carbon residue that usually leaves an outline of the organism on the rock formed by the sediment.
Last edit: 08:09, 28 January 2011
Preserving a specimen via amber is a really good way to keep a lot of detail. It starts out as a resin that comes from coniferous trees (trees that produce their seeds in cones, i.e. pine trees), very much like a tree sap. As the resin surfaces on the branches or trunk, it hardens. This is a method the trees use for protection from predators such as insects or browsing of larger animals. It can also protect cuts or breaks that happen to the tree, acting as a shield from more outside harm while the tree repairs itself. The resin will engulf the insect (or whatever is destined to become a fossil) completely and then hardens around it, preserving whatever it is exact way it looks. For the resin to harden into the next stage, something called copal. This is harder and more durable than the hardened resin, but it can still be destroyed rather easily. It takes thousands of years (sometimes even millions) for the resin to become amber, and it needs the right set of conditions for it to preserve correctly. It needs a lack of oxygen, so it works best if it’s submerged in sediments under water or something like that. The oxygen will eat away at the resin. The terpenes (a large class of hydrocarbons often found in many coniferous trees) in the resin is what causes the substance to harden into amber, by chemically linking themselves, like they’re being fused together.
“The specimen...is a classy piece of Baltic Oligocene amber trapping the best preserved spider in existence.”
"Amber." Fossil Preservation . Web. 27 Jan 2011. <http://www.t-rat.com/Pages/FossilPreservation.html>.
Last edit: 07:07, 11 February 2011
An interesting detailed scenario about how this process occurs is located on this website,http://www.fossils-facts-and-finds.com/how_are_fossils_formed.html, under the heading "How are fossils formed?Amber".
This is an interesting site, with lots of information. however, be warned that it is a commercial fossil dealer's site and not a professional site, so the information presented on it has not been vetted as much as an academic site and may not be as reliable.
Last edit: 15:08, 3 February 2011
For Lagerstatten descriptions, external link(s), and more taphonomic terminology please visit the Taphonomic discussion page located here:
Mummiciation is where an organism of some species is preserved by accident or on purpose, with the skin and organs being preserved. Conditions have to be really good for this to happen right, unaltered. Extreme cold temperatures, low humidity, and even in sand dunes with a lot of sand. Leaving very beautiful remains.
“Natural mummification of other animal species also occurs; this is most common in species from shallow saline water environments, especially those with a body structure which is particularly favourable to this process, such as seahorses and starfish.”
"Mummified Seahorse." Web. 1 Feb 2011.
Freezing is a form of preservation that occurs when an organism and all it's remains are unchanged throughout time. The most well know frozen fossils that have been found would be of the Wooly Mammoth. These fossils are found in Siberia; with hair, soft tissue, organs, and even undigested vegetation in the stomach. Even though frozen fossils are very hard to find; the mode of preservation is quite remarkable.
("Dima, a preserved baby Woolly Mammoth") Mammoth clone: Science or simply fiction?. Web. 28 Jan 2011.