Glossopteris

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Glossopteris browniana fossil in the Artis zoo, Amsterdam.
Fossils of the gymnosperm Glossopteris (dark green) found in all of the southern continents provide strong evidence that the continents were once amalgamated into a supercontinent Gondwana

Glossopteris [1] is the largest and best-known genus of the extinct seed ferns.

History[change | edit source]

The Glossopteridales arose in the Southern Hemisphere around the beginning of the Permian (~300 milliom years ago). Their distribution across several continents led Eduard Suess to suggest the southern continents were once together in a single supercontinentGondwana.[2]

These plants went on to become the dominant elements of the southern flora through the rest of the Permian but disappeared in almost all places at the end of the Permian (~250mya).

The only convincing Triassic records are very earliest Triassic leaves from Nidpur, India. Even these records are somewhat questionable owing to faulting and complex juxtapositioning of Permian and Triassic strata at Nidpur.

Although most modern palaeobotany textbooks cite the continuation of glossopterids into later parts of the Triassic and, in some cases into the Jurassic, these are mistakes based on misidentification of similar leaves such as those of Gontriglossa, Sagenopteris, or Mexiglossa.

Glossopterids were, thus, one of the major casualties of the end-Permian mass-extinction event.[3]

References[change | edit source]

  1. Greek glossa (γλώσσα), meaning "tongue", because the leaves were tongue-shaped
  2. McLoughlin S. 2012. Glossopteris – insights into the architecture and relationships of an iconic Permian Gondwanan plant. Journal of the Botanical Society of Bengal. 65(2), 1–14.
  3. McLoughlin S; Lindström S. & Drinnan A.N. 1997. Gondwanan floristic and sedimentological trends during the Permian-Triassic transition: new evidence from the Amery Group, northern Prince Charles Mountains, East Antarctica. Antarctic Science, 9: 281-298.