Aneurophytondouisp. nov., a New Species from the Mid Devonian

Updatetime: 2014-04-02

The Progymnospermopsida, being characterized by pteridophytic free-sporing reproduction but gymnospermous secondary vascular tissues, is subdivided into three orders: Aneurophytales, Archaeopteridales and Protopityales. Among them Aneurophytales is thought to be the most primitive. Genera in Aneurophytales established based on both morphological and anatomical characters include Tetraxylopteris Beck 1957, Rellimia (Dawson) Leclercqet Bonamo 1973, and Aneurophyton Kr?usel et Weyland 1923.

The diagnostic characters of Aneurophyton come mainly from the type species, A. germanicum Kr?uselet Weyland 1923, widely reported from the Middle Devonian of Euramerica (e.g. Serlin and Banks 1978; Schweitzer and Matten 1982).

Recently, Dr. JIANG Qing and her colleagues from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences described a new species Aneurophytondouisp. nov. (Aneurophytales, Progymnospermopsida)  from the late Middle Devonian Hujiersite Formation of Hoxtolgay, Xinjiang, northwest China, as a plant with at least four orders of axes and ultimate units (vegetative appendages/fertile organs). Spines cover the surface of all orders of axesand ultimate units. The second-order axes and the vegetative appendages are closely inserted in pairs and helically arranged. From the second order, axes of subsequent orders are produced by bifurcation. The vegetative appendages are unwebbed and up to three times dichotomous. The fertile organ is pinnate, and thefertile organ axes are opposite or subopposite with adaxial, elliptical sporangia.

This is the first formal report of Aneurophyton beyond the coasts of the Rheic Ocean. West Junggar, the locality of present species of Aneurophyton, played a key role in the dispersal of Aneurophytales in the Middle Devonian.

The paper was published in International Journal of Plant Sciences.

Related information of this paper: Jiang Q, Wang Y, Xu H-H*, Feng J. 2013.A new species of Aneurophyton(Progymnospermopsida) from the Middle Devonian of West Junggar, Xinjiang, China, and its paleophytogeographical significance.International Journal of Plant Sciences. 174: 1182-1200)


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