The Division of Arthropoda is integrated into Subdivision
associated Group of
Articulate Protostomia into
Animals Kingdom. The body is articulated into heterogeneous sections. They have
limbs in paired, most articulated, with anterior limbs are developed as antennas
or mouthparts. They have also a solid chitinous coat (cuticula), partially
embedded with calcium carbonate- or phosphate.
Animal phylums with complete digestive tract are part of the Protostomia (plastopore).
During the process of embryogenesis, the protostoma is developing to mouth
opening and the anus is rupturing secondarily. The Group of Protostomia with
coelum is presented by Articulate Protostomia.
Basically it's a biocenosis of mixed ecobiotic species inhabiting a definite
common area. Flora and fauna of the sea- flor are covered by the benthos.
system relative to fossils. Fossils don't occure inside a stratum in any
randomized way, but there are certain fossils leading for defined periods of
earth history (W. Smith, 1815 - Guiding value of fossils,key fossils).
By Biostratonomy one understands the science of organics body fate, from the
beginning of death until it's final embedment.
The term Cambrian is based on the Cambrian mountains of Northern Wales (Cambria
- roman name for Northern Wales). From geological view Cambrian is the earliest
stratigraphic System (Period) of the Palaeozoic. It began about 542 million
years before present day and continued about 54 million years. The Cambrian is
diveded into the Series Upper-, Middle- and Lower Cambrian. The lower boundary
of the Cambrian was set at the earliest appearance of early trilobites. During
the Cambrian period, trilobites (about 60%) and brachiopods represented the
major part of marine fauna.
This System is named for the extensive coal beds (Lat.- carbo- coal). It's
divided into the Subdivisions Upper- and Lower Carboniferous. It extends from
Devonians end 359 million years ago and ended to the beginning of the Permian
System 299 million years ago.
Condition of a type of hypostome regarding it's structure and anatomical
characteristics. At ventral view basically the hypostome can be attached to the
anterior doublure by sutures, or unlike this condition, it can be free of the
doublure. The conterminant condition discribes the attached condition. There's a
wide diversity relating sizes and shapes at this type of hypostome. At dorsal
view, hypostomes anterior edge is congruent to glabellas anterior edge (vitreous
cephalon ;-)). Examining a trilobite with a conterminant type of hypostome
mostly indicates watching a predator representative.
chronology associates biostratigraphical and lithostratigraphical units.
Chronostratigraphy globaly includes all strata of the earth, formed within
a definite period of time. From this strata, a geological time scale is created,
subdivided into the chronostratical units Eonothem, Erathem, System, Series and
This Period (System) was named for the Devonshire of Englands Southwest. The
Devonian is divided into Upper-, Middle- and Lower Series. It started before
nearly about 410 Million years, lasting about 55 Million years. Plants, Insecta,
fresh- water fishs ad first amphibians sucessfully colonized land and fresh-
water habitats. By the end of Devonian Graptolites and Tentactulata extincted.
The diagenesis of fossils examines organic bodys further destiny after its
The diversity (Lat.- diversitas) generally discribes the variety. The variety of
species are in this case discribed as quantity of different life forms (e.g.
representatives of different families) within the marine environment, the
biodiversity (Lat.- bios= life).
The division is a hierachical stage within the systematics (Classificating the
organisms into groups, taxa) of biology. The division is directly upordinated
the taxon kingdom, taxon class corresponding to this is subordinated.
The eumetazoa (tissue animals) envolving all kind of animals with real present
cellular tissues. There are organs, muscles and nerves present.
External organ of protection- orthesis (cuticula) of arthropods.
The hypostome (Gr.- mouth) is the trilobites pre- oral located mouthpart, an
ventral sided external part of the exoskeleton. There are three types of
hypostomes to differentiate: the natant type, the conterminant type and finally
the impendent type.
Another condition of a type of hypostome regarding it's structure and anatomical
characteristics. In principle the impendent type has conterminant condition with
differenced alignement to glabellas anterior edge (vitreous cephalon ;-)). That
means the hypostome is attached to the anteriour dubloure, but it doesn't match
(ventral sight) to the anterior glabellar border (dorsal view).
vertebral (spinal) column.
The Lithostratigraphy evaluates the sequence of rock strata, the
chonological seuence of development. The Lithostratigraphy is based on the Law
of Storage (N. Steno, 1669), the oldest stratum is positioned below, so it was
sedimented at earlier times than the upper layer of sediments. Therefore a
timebased sequence of layers can be created.
Another condition of a type of hypostome regarding it's structure and anatomical
characteristics. This kind of hypostome is free of the anterior dubloure. At
ventral view there' a congruence of hypostomes and glabellas anterior border (vitreous cephalon
;-)). Compared to the conterminant type, a simple ovoid shape is a typicylally
feature of the natant type, remained nearly unchanged over the complete period
of trilobites evolutionary time. One assumes that this kind of hypostomes
belongs to particle feeders.
The ontogenesis describes the developmental process (ontogenetic), starting with
the fertilized egg, processing the larval stage until the end of the species
specific complete development of the adult trilobite.
The naming of this system (period) based of the name of the celtic Welsh tribe
of Ordovices of Northern Wales, Great Britain (C. Lapworth, 1879). The
Ordovician is dividet into the Upper-, Middle- and Lower series. It started
before nearly about 488 Million years, lasting about 45 Million years. Beside
invertebrates, predominating in great diversity, the vertebrates with jawless
fishes were also represented abundantly. At the end of this period, a great
global mass extinction among the groups happened (probably caused by climatic
changes), also the trilobites were affected.
Basically this is a biozoenosis of different ecobiotic specialized species
in a defined common habitat. The pelagic habitat coveres the upper water layers
down to great water depth. Pelagic animals are moving fromactive swimming up to
Godparent of this last Palaeozoic period were the extensive exposures in the
region around the russian town Perm at the Urals western hillsides. The Permian
is divided into Upper- (Zechstein) and Lower (Rotliegendes) Permian. With the
coalescence of all Earth's major landmasses (except. parts of East Asia) the
supercontinent Pangea was developed. At Permian's end, the transition from
Palaeozoic to Mesozoic, fauna is affected by the greatest mass extinction in
earth history. The marine fauna decimated in a special amount. Additionally to
trilobites more species like Foranimifera of class Rhizopoda, the
representatives of predators of merostomatous the Eurypteridia a.l.m. extincted.
The naming of this system (period) is based on the rocks in the region of the 'Silurians'
(Southern Wales), a celtic tribe. The Silurian, lasting from 443 until 416
Million years ago, is divided into Upper- and Lower Silurian. This period is
characterized by the continent of Euramerica (Pre- Northern Europe+ Laurentian).
The stratigraphy (Lat.- Stratum = layer) describes the chronology of Earth
history using studies of geological processes and events, formulating a periodic
sequence of Earth history. Stratigraphy includes
In his publication 'Die Naturgeschichte der Versteinerung zur Erläuterung der
Knorrischen Sammlung von Merkwürdigkeiten der Natur', the indication 'Trilobit'
was introduced by Prof. Johann Ernst Immanuel Walch. The Class Trilobita
actually including nine Orders affirmed. This Orders again consisting of
more than 150 Families including more than 15000 described Species on its part.
Cause every year new Species are discovered, Class Trilobita is steadily