This is Mazon Monday post #340.  What’s your favorite Mazon Creek fossil?  Tell us at esconi.info@gmail.com.

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Neuropteris thompsoniana was described by William Culp Darrah (1909-1989), in 1969. Darrah was an American professor of biology at Gettysburg College, in Pennsylvania. He was a specialist in paleobotany. In addition to paleontology, Darrah had a deep interest in 19th century photography, and published several works on the subject.

His daughter, Elsie, wrote and edited book “Historical Perspective on Early Twentieth Century Carboniferous Paleobotany in North American”, which was dedicated as a memorial volume to her father.

N. thompsoniana is a very rare variety of Neuropteris. It is referred to as Neuropteris thompsonii is some sources. Darrah found the venation different than most neuropterids and more similar to odontopterids.

Neuropteris thompsoniana was named for Frederick (Fred) Oliver Thompson (1883-1953), who was a prolific amateur collector and patron of paleobotany. Unfortunately, he’s been a little forgotten as they years have passed. More about his life can be found in the book “Historical Perspective on Early Twentieth Century Carboniferous Paleobotany in North American”, which we covered in Mazon Monday #97. Thompson has a few more species named in his honor – Macrostachya thompsonii (Darrah, 1936a), Arctinurus thompsoni (Miller and Unklesbay, 1944), Euproops thompsoni (Raymond, 1944), Medullosa thomsonii (Andrews, 1945), Sphenostrobus thompsonii (Levittan and Barghoorn, 1948), Mesoxylon thompsonii (Traverse, 1950),  and Mariopteris thompsonii  (Darrah, 1969). It is interesting to note that Thompson had collected all of those specimens himself over his 20 years of fossil collecting.

Jack Wittry discusses N. thompsoniana on page 209 of his book “A Comprehensive Guide to the Fossil Flora of Mazon Creek.”

Neuropteris thompsoniana Darrah, 1969

1969. Neuropteris thompsoniana Darrah: p. 99, pl. 54, fig. 2

DESCRIPTION: The penultimate pinnae are distant, linear-lanceolate, and opposite to subopposite. The pinnules are alternate or subopposite, ovate, rounded at the apex, and slightly constricted at the base. The terminal pinnule is small and triangular. The venation is distinct, straight or slightly arched, thin, and distant. The pinnules lack true midveins. Instead, a central vein enters the pinnule where it immediately divides 2 to 4 times. Usually, one or more additional veins enter from the rachis on each side of the central vein, divide near the base, and possibly once more.

REMARKS: Neuropteris thompsoniana is very rare. Darrah noted that this taxon’s venation approaches odontopterids, but in his opinion, the constricted bases of the pinnules removed it from this group.

Photos