Friday, June 28, 2013

Content Highlights - Small Shelly Fauna

Early in the Earth history, at the beginning of the Cambrian period, the first assemblage of multicellular organisms with hard skeletal parts appeared. In the Lower Cambrian rocks, paleontologists all over the world have discovered minute shells and sclerites which are together called “small shelly fauna”.

Aldanella kunda from Europeana - image is under CC BY-SA of Museum of Geology, University of Tartu.

Small shelly fauna is an artificial designation of various skeletal parts of various groups of animals. This fauna appeared in fact just before the beginning of the Cambrian period, but its greatest diversity is achieved in the early Cambrian.

Detail of Aldanella from Europeana - image is under CC BY-SA of Museum of Geology, University of Tartu.

Shape of sclerites varied from conical shells, spines to small plates. Some of these fossils look familiar, for instance Aldanella, which clearly is a mollusk. Others look strange and could represent fragments of larger organisms like sponges, velvet worms related animals, brachiopods, etc.

Fossils of the small shelly fauna are usually composed of calcium phosphate, calcium carbonate or silica. These minerals might not have originally built the shell; they rather replace the original material during fossilization. It is assumed that the invention of the shell in some of these organisms is a consequence of the onset of first predators.

Monday, June 17, 2013

Content Highlights - Auroch (Bos primigenius)

Did you know that the auroch is the predeccessor of present domestic cow and that the last auroch died in 1627 in the Jaktorów Forest, Poland?

Bos primigenius from Europeana - image is under CC BY-SA of Museum of Geology, University of Tartu.

Auroch was a large, even-toed ungulate (Artiodactyla) herbivore with short black hair and gray or yellowish stripe across the back in males and reddish-brown hair in females. The animal grew up to 2 m of height and 800-1000 kg in weight. Aurochs were pressumablly bound to swamps and swamp forests, such as river valleys, river deltas, and bogs, but they might have also lived in drier forests and perhaps in open grasslands. The animals lived in herds and has social behaviour similar to present domestic cattles.

Bos primigenius from BHL.

As evidenced from fossil remains and other proofs (painting in caves, artefacts), Bos primigenius first appeared in India 2 million years ago and was first domesticated there as early as 9 thousand years ago. From India, Bos primigenius migrated into the Middle East and reached Europe about 270 thousand years ago. In Europe, the animal was among the largest post-glacial herbivores and went domesticated about 6 000 years ago. In a summary, Bos primigenius originally inhibited most of Europe, Northern Africa, middle East, central Asia and India being a common prey of humans as early as in the Paleolite. Hunting finally led to its extinction in the 17th century. Only the Eurasian subspecies (Bos primigenius primigenius) managed to survive until now and is at present distributed worldwide under domestication. From the original species, it differs in smaller size and weight, colour and usually shorter horns. Since the beginning of the 20th century, attemps have been made to breed the original auchor back from the domectic cattles and thus return it back to the wild after 400 years.

Monday, June 3, 2013

Content Highlights - Houseleek (Sempervivum)

Houseleek is a flowering plant which occurs in rockeries and rooftops. Did you know that since antiquity, houseleeks were planted on roofs, because it was believed that they guarded homes against lightning and fires? Indeed, it could create a fire-resistant layer on the roof.

Houseleek from Europeana - image is under CC BY-SA of
Biologiezentrum der Oberoesterreichischen Landesmuseen. 

Houseleeks occur in about fifty species, from northern Africa, through Europe, to the Caucasian mountains. They occupy hilly to mountainous terrain in these areas. They are succulents - plants adapted to growth in places with little water. They prefer rocky outcrops and rock steppes. They are very undemanding, both for nourishment and for water.

Houseleeks from BHL.

Houseleek juice is rich in nutrients, has disinfectant properties and is an anti-inflammatory. Similarly to aloe vera, houseleeks are very effective in treating burns, scaldings, frostbite and sunburn. They reduce pain from insect bites, alleviate itching, redness and swelling.

Learn more about houseleek in "nature at your home". Stay tuned!