A second quarry (in the same geological formation) was opened. A thorough reassessment of the Burgess Shale showed that the fauna were much more varied and unusual than Walcott had realised. The Royal Ontario Museum now has the largest collection of Burgess Shale material in the world with over 150,000 specimens. Many of the animals present had bizarre anatomical features and only the slightest resemblance to other known animals. Examples include "Opabinia", with five eyes and a snout like a vacuum cleaner hose; "Nectocaris", and "Hallucigenia". This last was originally reconstructed upside down, walking on its spines.
The Burgess Shale was designated a UNESCO World Heritage Site in 1980. It became part of the Canada Rocky Mountain Parks World Heritage Site in 1984.
Solnhofen limestone
The Solnhofen limestone is the world's most famous fossil site. It is a lagerstätte of Upper Jurassic limestone which has preserved many fossils in great detail. The specimens of "Archaeopteryx" are perhaps the world's most valuable fossils, because they are the earliest fossils of a bird capable of flight.
The Solnhofen beds lie in the German state of Bavaria (Bayern), halfway between Nuremberg (Nürnberg) and Munich (München). They were originally quarried as a source of roof and floor tiles, then for lithographic printing.
In the late Jurassic this area was an archipelago at the edge of the Tethys Sea. This included placid lagoons which had limited access to the open sea because they were surrounded by coral reefs. Water runoff from the land was low and, under the sun, evaporation was high. Salinity rose so high that the resulting brine could not support life, except at the top of the water column.
The lowest water was not only very salty, but hypoxic: very low in oxygen. This was caused by the lack of water mixing. Many ordinary scavengers were absent from the lagoon floor. From the condition of the water, it follows that almost all of the fossilised animals were not living in the lagoon. They must have lived on land, in the air, or out to sea beyond the reef. Then when they died, they fell, drifted, or were washed into the lagoons from the air, ocean or land. Occasional storms at sea would have killed flying animals, and swept fish over the reef in a suspension of finely-dispersed lime. There the bodies sank into the dead zone and were preserved.
Once in the lagoon, bodies became buried in soft carbonate mud. Thus, many delicate creatures avoided consumption by scavengers or being torn apart by currents. The wings of dragonflies, the imprints of stray feathers, and terrestrial plants that washed into the lagoons were all preserved.
"The variety and number of fossils known is deceptive. The occurrence of fossils is quite low. Indeed, a worker can quarry for an entire day and find not a single one. The hundreds of years of quarrying are what make them seem so apparently common".
The range of fossil species gives a comprehensive picture of a local Jurassic ecosystem. At times, the lagoons almost dried out, exposing sticky carbonate muds that trapped insects and even a few small dinosaurs. Over 600 species have been identified. Seven genera and up to 29 species of pterosaur have been found. This suggests that in this ecosystem pterosaurs were more common and diversified than birds. The pterosaur sizes ranged from that of a sparrow to 1.2 m (4 ft) in length.
The fine-grained texture of the mud silt forming the limestone is ideal for making lithographic plates for printing illustrations. Extensive quarrying in the 19th century revealed many fossil finds, as commemorated in the name "Archaeopteryx lithographica", all the specimens of which come from these deposits. The closest modern analogue to the Solnhofen conditions is said to be Orca Basin in the northern Gulf of Mexico, though that area is much deeper than the Solnhofen lagoons.
The Solnhofen biota is composed of the animals and plants which lived in the area. All were found in the limestone quarries.
The carbonate was produced mainly by:
Both these groups produce calcium carbonate skeletal structures.
Some of remains of the land plants got down into the lagoon. They were almost all gynmosperms.
The data show some things about the biota of the region.
Aenictogiton
Aenictogiton is a genus of ants. The genus has seven species. The genus is given its own subfamily, Aenictogitoninae. All of the species are known only from males from middle Africa and show a phylogenetic liking to the army ants (and are in the dorylomorph subfamilies). Nothing is known about the workers, queens and behavior of these ants. A few not described species are known to exist in a few collections in the world.
Ketosis
Ketosis is when there are greater levels of ketone bodies in the blood or urine. It comes when ketone bodies are released into the bloodstream due to low glycogen levels in the liver. Ketone bodies are made by a process called ketogenesis. Ketosis can be understood as the use of body fat as a source of energy. Ketosis has 3 main sources of energy, also known as ketone bodies: acetoacetate, acetone, and beta-hydroxybutyrate.
Melphalan
Melphalan is a chemotherapeutic agent used in the treatment of a variety of cancers, including melanoma and multiple myeloma.
Rhabdomyosarcoma
Rhabdomyosarcoma is a rare type of cancer that is most common in children. Rhabdomyosarcoma is a cancer that begins in muscle tissue - usually the muscles that are attached to bones to help a person move.
Rhabdomyosarcoma should not be confused with rhabdomyolysis, which is often called "rhabdo" for short.
There are three different kinds of rhabdomyosarcoma.
This is the most common type of rhabdomyosarcoma. More than half of people with this cancer have ERMS. It is most common in children under age 6.
Embryonal rhabdomyosarcoma usually happens in:
This is the second most common type of rhabdomyosarcoma. Alveolar rhabdomyosarcoma is more common in older children and teenagers, but it can also happen in younger children and adults.
ARMS usually happens in the big muscles in:
However, it can also happen in the genitals or the area around the anus.
This type of rhabdomyosarcoma usually grows faster than embryonal rhabdomyosarcoma, and needs more treatment than ERMS.
Anaplastic rhabdomyosarcoma does not happen very often. When it does happen, it usually affects adults; is very rare in children.
This type of cancer usually grows quickly and needs a lot of treatment.
The choice of how to treat rhabdomyosarcoma depends on many things. For example:
Based on all of these things, the patient and their medical team can decide what treatment is best. There are three types of treatments for rhabdomyosarcoma:
The prognosis of a person with rhabdomyosarcoma also depends on many different things. For example, adults with rhabdomyosarcoma usually have tumors that grow faster and are harder to treat. Prognosis also depends on the type of rhabdomyosarcoma a person has, what kind of treatment they get, whether their cancer has spread, and many other things.
Underweight
The term underweight refers to humans that have much less weight than they should. Being underweight is bad for the overall health of the person affected. It is normal what a person's weights changes over time. Being underweight is often defined using a measure called the body mass index which calculates a score, based on height and weight. If this score is below 18.5, a person is generally said to be underweight. This is only a general indication, though as the scores must not be calculated for everyone. It does not apply to children and adolescents, for example.
Being underweight can have different causes: