Wednesday, February 18, 2009

IN GENERAL about radiolarians

Physiology of radiolarian

diagram of the relation between the soft parts within a radiolarian

I assume that there is a direct relationship between the soft- and the hard parts (skeleton) of the radiolarian. But I can not prove this yet. needs more research.

Orders, generations & family's of radiolarians
Within the extremely large number of existing radiolarian species, there are (at least) two major extant groups to be clearly distinguished.

Type I'm interested in

I have decided to base my research on either Spumellaria or Nassellaria. Those orders are the best known by geologists and in my opinion they have the most spatial qualities aswell. The Spumellaria could be used as a basis for an architectural roof construction while the Nassellaria could be translated into a complete pavilion.
I will specify myself more on this in a later post.

first 3 sketches are spumellaria & last 3 are nasselaria

Some other basic principles:
Radiolarians exist for 600 million years. There lifespan lies between a few days and 2 weeks. Radiolaria evolve rapidly, that's why they are really usefull biostratigraphic (study of the spatial and temporal distribution of fossil organisms) tools. Because they exist out of soft and hard parts, the fossils are never complete, this applied difficulties in research.

Structural principles of skeleton:

- skeletal elements do not meet at the center even if they are radial symmetrical.
- their are materialized out of minerals
- (i will get to the different types of radiolarians and zoom in for more info)

Growing principles of skeleton:

- Skeletal elements are covered with a layer of cytoplasm which is rapidly withdrawn if the organism is disturbed. It is suggested new material is formed within this sheath (cytokalyamma) and that it acts somehow like a dynamic mould.

- Almost nothing is known as to the hard parts of radiolaria, except that the vacuolated layer (see first diagram of this post) is able to secrete silica or other mineral substance.

- The evoluation of the skeleton of both Spumellaria and Nassillaria is described in the picture below.

evoluation process of Spumellaria (src: C. Moore, Treatise on Invertebrate Peleontology)

evoluation process of nassellaria (src: C. Moore, Treatise on Invertebrate Peleontology)

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