Melanosclerite Temporal range:
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Cnidaria (?) |
Order: | †Melanoscleritoitidea Eisenack, 1963 |
Family: | †Melanoscleritoitidae Eisenack, 1942 |
The Melanosclerites are a group of problematic microfossils obtained by palynological processing.
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.[1] 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.[2]
The affinity of melanosclerites is uncertain; algal has been proposed, but hydrozoan (cnidarian) is preferred, though not conclusively established.[1] Melanoscleritoites Eisenack, 1963 is interpreted as a hydrozoan,[3] 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,[1] 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'.[3]
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.[1]
Taxa include: