This is Mazon Monday post #256. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
-----------------------------------------------------
Drawings by George Langford, Sr. (George's Basement)
Sphenophyllum emarginatum is a species in the order Sphenophyllales, which is an extinct order of plants that existed from the late Pennsylvanian to the Early Permian. They are a sister taxa to the present day Equisetales (horsetails). The parent plant was probably similar to Calamites.
Sphenophyllum emarginatum was named in 1828 by the Adolphe-Theodore Brongniart (1701-1876). Brongniart, a French paleontologist, is considered by many to be the father of paleobotany. He described many Carboniferous plants.
Sphenophyllum emarginatum was one of two Mazon Creek plant species on George and Sydne Langford's Christmas Card in 1939. S. emarginatum is on the left.
Sphenophyllum emarginatum appears on page 69 of Jack Wittry's "A Comprehensive Guide to the Fossil Flora of Mazon Creek".
Sphenophyllum emarginatum Brongniart, 1828
1828. Sphenophyllum emarginatum Brongniart: p. 68
1880. Sphenophyllum emarginatum Brongniart; Lesquereux: p. 53
1925. Sphenophyllum emarginatum Brongniart; Noé: p. 14, pl. 6, figs. 3-6
1958. Sphenophyllum emarginatum Brongniart; Langford: p. 55, figs. 78, 80
1958. Sphenophyllum emarginatum Brongniart, Abbott: p. 339, pl. 38, figs. 29, 34; pl. 44, fig. 66; pl. 45, fig. 72
1964. Sphenophyllum emarginatum Brongniart; Boureau: p. 52, fig. 24
1969. Sphenophyllum emarginatum Brongniart; Crookall: p. 586, pl. 107, fig. 6
1979. Sphenophyllum emarginatum Brongniart; Janssen: p. 92, figs. 79a, 80DESCRIPTION: The main stem grows in four orders of branches. Stems are ribbed and branch at enlarged nodes. The most common leaf form is wedge-shaped, widest at the distal end, less than 10 mm in length, and usu-ally with 6 to 8 leaves per whorl at an enlarged node (see Figs. 1, 4). The sides of the leaves are straight. The distal edge is straight or slightly arched, generally with 6 to 12 small, rounded teeth. A single vein enters the leaf base, divides three or four times, and terminates in the distal margin with one vein entering each of the rounded teeth. There are several other leaf forms found to grow on this plant depending on branch position. The distal leaves of the last order of branching are deeply dissected with 4 to 6 sharply pointed lobes that terminate in a hooked spine (see Figs. 2, 3A). Leaves on lower order branches are more elongated, up to 2 cm long (see Figs. 3C, 5, 6).
REMARKS: Sphenophyllum emarginatum is very common and by far the most common sphenophyll in the Mazon Creek flora.
Specimens
From Wittry's "A Comprehensive Guide to the Fossil Flora of Mazon Creek".
From George's Basement
