Sigillaria

Sigillaria is a genus of extinct, spore-bearing, arborescent (tree-like) plants. It was a lycopodiophyte, and is related to the lycopsids, or club-mosses,[1] but even more closely to quillworts, as was its associate Lepidodendron.

For the Roman holiday and associated gifts, see Sigillaria (Ancient Rome).

Sigillaria
Temporal range: Carboniferous-Permian, 323.2–254.0 Ma Possible Devonian record
Sigillaria tree (Stigmaria) from Stanhope, County Durham, UK
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Lycophytes
Class: Lycopodiopsida
Order: †Lepidodendrales
Family: †Sigillariaceae
Genus: †Sigillaria
Brongniart (1822)

Fossil records

This genus is known in the fossil records from as early as the Middle Devonian or the Late Carboniferous period [2] but dwindled to extinction in the Early Permian period (age range: from 383.7 to 254.0 million years ago).[1] Fossils are found in Great Britain, United States, Canada, China, Korea, Tanzania and Zimbabwe.[3]

Species
Fossil of Sigillaria trigona, on display at National Museum (Prague)

Species within this genus include:[4]

  • S.alveolaris Brongniart (1828)
  • S.barbata Weiss (1887)
  • S.bicostata Weiss (1887)
  • S.boblayi Brongniart (1828)
  • S.brardii Brongniart (1828)
  • S.cancriformis Weiss (1887)
  • S.cristata Sauveur (1848)
  • S.cumulata Weiss (1887)
  • S.davreuxii Brongniart (1828)
  • S.densifolia Brongniart (1836)
  • S.elegans Sternberg (1825)
  • S.elongata Brongniart (1824)
  • S.fossorum Weiss (1887)
  • S.hexagona Brongniart (1828)
  • S.loricata Weiss (1887)
  • S.mammiliaris Brongniart (1824)
  • S.menardi Brongniart (1828)
  • S.micaudi (Zeller (1886-1888)
  • S.monostigma Lesquereux (1866)
  • S.orbicularis Brongniart (1828)
  • S.ovata Sauveur (1848)
  • S.pachyderma Brongniart (1828)
  • S.principes Weiss (1881)
  • S.reticulata Lesquereux (1860)
  • S.rugosa Brongniart (1828)
  • S.saulii Brongniart (1836)
  • S.schotheimiana Brongniart (1836)
  • S.scutellata Brongniart (1822)
  • S.sillimanni Brongniart (1828)
  • S.tesselata Brongniart (1828)
  • S.transversalis Brongniart (1828)
  • S.trigona Sternberg (1826)
  • S.voltzii Brongniart (1828)

Description

Sigillaria was a tree-like plant reaching a height up to 30 meters,[2] with a tall, single or occasionally forked trunk[1] that lacked wood. Support came from a layer of closely packed leaf bases just below the surface of the trunk, while the center was filled with pith. The long, thin grasslike leaves[5] were attached directly to the stem and grew [2] in a spiral along the trunk.[1] The old leaf bases expanded as the trunk grew in width, and left a diamond-shaped pattern, which is evident in fossils. These leaf scars were arranged in vertical rows.[2] The trunk had photosynthetic tissue on the surface, meaning that it was probably green.

The trunk was topped with a plume of long, grass-like, microphyllous leaves,[5] so that the plant looked somewhat like a tall, forked bottle brush. The plant bore its spores (not seeds) in cone-like structures [5] attached to the stem.[1][6]

Sigillaria, like many ancient lycopods, had a relatively short life cycle - growing rapidly and reaching maturity in a few years. Some researchers have suggested that Sigillaria was monocarpic, meaning that it died after reproduction, though this is not proven.[5] It was associated with Lepidodendron, the scale tree, in the Carboniferous coal swamps.[2]

Bibliography
  • William A. DiMichele, Richard M. Bateman: The Rhizomorphic Lycopsids: A Case-Study in Paleobotanical Classification. Systematic Botany, 1996, Band 21, S. 535-552.
  • Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants. Second Edition, Academic Press 2009, ISBN 978-0-12-373972-8. S. 303-307
  • J. W. Sir Dawson - On the structure and affinities of Sigillaria, Calamites and Calamodendron - Paperback – August 16, 2011 ISBN 1175560871
  • Silva Pineda, A. (2003). "Flora del Pérmico de la región de Izúcar de Matamoros, Puebla". En Soto, L. A. Agustín Ayala-Castañares: universitario, impulsor de la investigación científica. UNAM. p. 371. ISBN 9789703207893

References
  1. Encyclopædia Britannica
  2. Hans' Paleobotany Pages - The clubmoss tree Sigillaria
  3. Paleobiology Database
  4. Hans' Paleobotany Pages - Species of Sigillaria
  5. Encyclopedia of life
  6. Sebastián González, D. and Celia Gutiérrez, M. (2014). El Bosque Petrificado de Olta: 300 millones de años después ISBN 9781312079465
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