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