This is Mazon Monday post #183. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
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Sphenopteris plicata was described by Leo Lesquereux in 1858. Lesquereux (1806 - 1889) described much of the North American Carboniferous flora in the mid 1800's as a consultant to various US state geological surveys. His book "Atlas to the Coal Flora of Pennsylvania and the Carboniferous Formation throughout the United States" written from 1879 to 1884 was the standard reference for the Carboniferous flora in the US for many years.
From George's Basement
Sphenopteris plicata was appeared on page 148 of Jack Wittry's "A Comprehensive Guide to the Fossil Flora of Mazon Creek".
Sphenopteris plicata Lesquereux, 1858
1858. Sphenopteris plicata Lesquereux: p. 862, pl. 11, fig. 3
1879-80. Sphenopteris plicata Lesquereux: p. 292
1884. Sphenopteris plicata Lesquereux: p. 763, pl. 111, fig. 28
1958. Sphenopteris plicata Lesquereux; Langford: fig. 504, no textDESCRIPTION: The penultimate rachis is straight and round. The ultimate rachis is linear-lanceolate, distant, and borne at a slight angle. The pinnules are oblique, decurrent, serrate, and terminate in a half-round, serrated lobe. Fully developed pinnules have three ser- rated lobes per side. The lobes range from short and marginal to nearly free, entire pinnules. The midveins are weak and decurrent. The lamina is thin, often making the margins indis- tinct. The lateral veins are often indistinct. When visible, they appear distant, very thin, branch once or twice, and terminate in a tooth at the margin.
REMARKS: Sphenopteris plicata is very rare. In Lesquereux's original description, he erroneously called the lobes rounded or crenulate. In an close examination of the holotype (see Fig. 2) by this author, the lobes were found to be serrated.
Photos
From Wittry
From George Langford Sr.