NAME Laevitubulus plicatus
AGE Late Ordovician to Early Devonian.   AGE span: 460.9...397.5 mya
K&J CLASSIFICATION (2000) Fungi Imperfecti, Mycelia sterilia.
FIGURE(S)
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Pl.30fig.14.jpg
FIGURE REFERENCE Burgess ND, Edwards D. 1991. Classification of uppermost Ordovician to Lower Devonian tubular and filamentous macerals from the Anglo-Welsh Basin; Botanical Journal of the Linnean Society, v. 106, p. 41-66.
SPECIES, AUTHORITY L. plicatus Burgess & Edwards 1991, p. 49, fig. 8.
LOCATION Anglo-Welsh Basin, Great Britain.
ORIG DESCRIPTION* Flattened tubes 17-55 µm in diameter, unbranched, and of indeterminate length. Wall ca. 1 µm thick, translucent and with occasional folds. These translucent, unbranched tubes are at least 500 µm long with thin, often folded walls of uniform thickness. End walls, or tapering indicating a termination, have never been seen. Tubes are occasionally loosely aggregated in monospecific wefts without preferred orientation, and many appear slightly degraded.
COMMENTS* Laevitubulus tenuis has opaque, seldom folded walls. Laevitubulus laxus is narrower, branched and generally found in monospecific wefts. Johnson (1985) illustrated (Plate 13, fig. 2) a similar specimen from the early Llandovery Tuscarora Formation of Pennsylvania, USA. McGregor & Narbonne (1978) figured another (Plate 2, fig. 7) from the late Ludlow Read Bay Formation of Arctic Canada. Some tubes referred to this species may be degraded or thin-walled examples of nematophytalean tubes. However, the taxon appears to have diverse origins because similar, although wider, tubes are seen as parts of chitinozoans (fig. 11), a group of problematic microfossils believed to be of animal origin (Williams & Sarjeant, 1967). Another possibility is that smaller examples are the sheaths of cyanobacteria, as are sometimes recovered from Precambrian clastic sediments although no indication of filamentous organization has been seen in the Silurian examples.

Derivation: from Latin plicatus-folded, referring to tube wall.
PUBLICATION REFERENCE Burgess ND, Edwards D. 1991. Classification of uppermost Ordovician to Lower Devonian tubular and filamentous macerals from the Anglo-Welsh Basin; Botanical Journal of the Linnean Society, v. 106, p. 41-66.
K&J REMARKS
TYPE
ALL NAMES (Including synonyms) Laevitubulus plicatus
SERIAL NUMBER 885
PUBLIC COMMENTS
 *For source, see Publication Reference.