Fossils on the Isle of Wight
There are a great many fossils to be found on the Isle of Wight. Fossils (from Latin fossus, literally ´having been dug up´) are the mineralised or otherwise preserved remains or traces (such as footprints) of animals, plants, and other organisms. The totality of fossils and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record.
The study of fossils is called palaeontology. Fossil fish of the genus Knightia fossils usually consist of the disarticulated or partially preserved remains of the organism itself. However, fossils on the Isle of Wight may also consist of the marks left behind by the organism while it was alive, such as the footprint or faeces of a dinosaur or reptile. These types of fossil are called trace fossils (or ichnofossils) as opposed to body fossils. Finally, past life leaves some markers that cannot be seen but can be detected in the form of chemical signals; these are known as chemical fossils or biomarkers.
Fossils on the Isle of Wight with exceptional preservation are known as Lagerstätten. These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying decomposition. Lagerstätten span geological time from the Cambrian. Examples are the Cambrian Maotianshan shales and Burgess Shale, the Devonian Hunsrück Slates, the Jurassic Solnhofen limestone, and the Carboniferous Mazon Creek localities.
Petrified wood fossil formed through permineralisation. The internal structure of the tree and bark are maintained in the permineralisation process.The oldest known structured fossils are most likely stromatolites. Now understood to be formed by the entrapment of sediment by mucous-like sheets of cyanobacteria, the oldest of these formations dates from 3.5 billion years ago. Even older deposits (3.8 billion years old) of heavy carbon that are indicative of even earlier life are currently proposed as the remains of the earliest known life on Earth.
Ever since recorded history began, and probably before, people have found fossils, pieces of rock and minerals which have replaced the remains of biologic organisms or preserved their external form. These fossils, and the totality of their occurrence within the sequence of Earth´s rock strata is referred to as the fossil record. The fossil record was one of the early sources of data relevant to the study of evolution and continues to be relevant to the history of life on Earth. Palaeontologists examine the fossil record in order to understand the process of evolution and the way particular species have evolved.