|Ultrastructure of Lagenochitina esthonica (Chitinozoa)
Maja Anna Korwin-Kossakowska
Eisenack, A. 1972. Neue Mikrofossilien des baltischen SilursIV. - Paleontologische Zeitschrift 19, 3/4, 217-243.
Mierzejewski, P. 1981. TEM study on ultrastructure of chitinozoan vesicle wall. - Cahiers de Micropaleontologie 1, 59-62.
Mierzejewski, P. 1983. NiektĂłre maĹ‚o znane mikroskamieniaĹ‚oĹ›ci organiczne z ordowiku i syluru Polski. - Rozprawa doktorska (maszynopis),
Instytut Palebiologii PAN, Warszawa..
See also: Cyathochitina campanulaeformis (Eisenack 1931)
Studies on the chitinozoan vesicle wall were undertaken with transmission electron microscope by a few
authors, namely Sven Laufeld (unpublished results), Alfred Eisenack (1972) and Piotr Mierzejewski (1981,
Piotr Mierzejewski examined vesicle walls of three species, i.e., Desmochitina nodosa Eisenack,
Lagenochitina esthonica Eisenack and Parachitina curvata Eisenack.
The vesicle walls of Desmochitina and Lagenochitina have a distinctly bizonal structure. The outer zone has a
loose, porous structure, whereas the inner zone is completely compact.The proportion of the thickness of the
outer and inner zones is only a little variable even within limits of one and the same specimen. In regard to
electron density, the substance of the outer zone is identical with the basic substance of the inner one. The
basic substance is completely amorphous.
There is a characteristic inner lining on some parts of the inner surface of the vesicle wall. It is made up of
the substance of less electron dense material than the substance of the vesicle wall. The inner lining might be
one - two or three - layered in the same specimen, tightly adhered to the vesicle wall as well as less or more
removed into the inside of the vesicle.
Explanations of figures:
1. SEM micrograph of
2. Transverse section through
the vesicle wall. TEM
3, 4. Different forms of the
inner lining of the vesicle wall.
c, inner cavity of the vesicle; i,
inner zone of the wall; il, inner
lining; o, outer zone of the