Melanosclerite

The Melanosclerites are a group of problematic microfossils obtained by palynological processing.

Morphology
The form-taxon contains a wide array of rod-like fossils, 100 μm to some mm long, that culminate in a broad bulbous 'head', often separated from the stalk by a constriction. The bulbous end may bear broad 'prongs', giving the appearance of the end of a human femur where the prongs are paired, although the prongs often occur in higher number – five, six, a dozen – with some resemblance to Namacalathus.

Affinity
The affinity of melanosclerites is uncertain; algal has been proposed, but hydrozoan (cnidarian) is preferred, though not conclusively established. Melanoscleritoites Eisenack, 1963 is interpreted as a hydrozoan, with other taxa not attributable to that particular class, on the basis of a broad morphological similarity – though the distinguishing features are far from unequivocal, and the preservation of the material raises some taphonomic problems. The composition resembles that of chitinozoans, scolecodonts, graptolites, and fungi – though at least one species of extant cubomedusan hydroid does produce a similarity resilient "chitinous" 'wall'.

Occurrence
They have been reported in shallow marine sandstones and limestones, as well as upper slope and open marine sediments, in strata from the Lower Cambrian to Upper Devonian.

Taxa include:
 * Eichbaumia Schallreuter, 1981
 * Eichbaumia incus Schallreuter, 1981
 * Melanoarbustum Górka, 1971
 * Melanoarbustum balticum Górka, 1971
 * Melanoclava Eisenack, 1942
 * Melanoclava betaotda Eisenack, 1942
 * Melanocyathus Eisenack, 1942
 * Melanocyathus dentatus Eisenack, 1942
 * Melanoporella Górka, 1971
 * Melanoporella polonica Górka, 1971
 * Melanoporella bulla
 * Melanoporella clava Schallreuter, 1981
 * Melanorhachis Eisenack, 1942
 * Melanorhachis regularis Eisenack, 1942
 * Melanoscleritoites Eisenack, 1963
 * Melanosteus Eisenack, 1942
 * Melanosteus acutus Eisenack, 1942
 * Melanostylus Eisenack, 1963
 * Melanostylus coronifer Eisenack, 1963
 * Menola Schallreuter, 1981
 * Menola os Schallreuter, 1981
 * Mirachitina Eisenack, 1963
 * Mirachitina quadrupedis Eisenack, 1963
 * Semenola Schallreuter, 1981
 * Semenola semen Schallreuter, 1981