Rothwellopteris pecopteroides

Name

Rothwellopteris pecopteroides

Rank

Species

Generic Name

[Genus] Rothwellopteris

Authors (Pub.)

He X.-Y. Wang S.-J. Wang J. Hilton J.  

Publication

The anatomically preserved tripinnate frond Rothwellopteris pecopteroides gen. et sp. nov. from the Latest Permian of South China: timing the stem to crown group transition in Marattiales [2019/8]

Journal

International Journal of Plant Sciences

Volume

180

Issue

8(10.1086/704946)

Page number

000 [3]

Year

2019

Fossil Status

foliage (fertile)

Stratigraphy

Lopingian

Strat. comment

Xuanwei Formation

Location

Panxian Mine District, Guizhou Province, China

Paleoregion

Cathaysia (South)

Data for Holotypus

Repository

Institute of Deep Time Terrestrial Ecology, Yunnan University, Kunming, China

Repository Number

YNUPB11001

Diagnosis

Vegetative frond. A tripinnate compound leaf. Rachis robust, main rachis up to 3 cm in diameter and primary pinna rachis up to 1 cm in diameter. Ultimate pinna rachis bears subopposite pinnules, pinnules tongue shaped or somewhat falcate, with length-to-width ratio less than 3∶1. Lateral margin of pinnules thickened, pinnule base slightly expanding; pinnule midrib thick, lateral veins forking twice and nearly perpendicular to the pinnules’ lateralmargin. Pinnulemargins slightly downturned. Palisade tissue well developed, vascular bundle sheaths marked by ridges on abaxial pinnule surface. Surface of themain rachis and primary pinna rachis undulate. Cell walls of the epidermis thick. Cortex divided into inner and outer cortex. Outer cortex further divided into inner and outer zones; outer zone consisting of continuous parenchyma with uniform cell size; inner zone being continuous or discontinuous sclerenchyma bands. Central part of rachis consisting of ground tissue and many small vascular bundles or meristeles arranged in polycycles. Abundant tannin cells in ground tissue.Vascular bundles in the outmost cycle possessing a well-developed sheath with its thickness greater on the pinna abaxial side than on the adaxial side. The ultimate pinna rachis possesses two cycles of vascular bundles, each consisting of four vascular bundles.