This is Mazon Monday post #243. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
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Langford, in 1958
Radstockia kidstonii is a very rare plant fossil from the Mazon Creek deposit. It is currently considered a true fern, as the pinnules and fertile structures are similar to the modern fern Marattia alata. It was originally named Radstockia sphenopteroides by George Langford in his first book "The Wilmington Coal Flora From a Pennsylvanian Deposit in Will County Illinois" in 1958. It was later reclassified by Thomas N. Taylor in "On the structure and phylogenetic relationships of the fern Radstockia kidston." in 1967. The National Academy of Sciences has a nice Biographical Memoirs about Professor Taylor. Taylor named Radstockia kidstonii for Robert Kidston a Scotish botanist and paleobotanist.
Tom Taylor was, simply put, a larger-than-life figure. His array of accomplishments in the field of paleobotany, and there were many, was outstanding. His personality was powerful, expansive, charming, and he was charismatic. He was generous to a fault. Tom’s remarkable ability to focus on tasks and his time management skills were amazing. He was a great friend and an effective and dedicated mentor to many graduate students, postdocs, and young colleagues. He was field leader, not only in research, but also in his ability to organize and energize his colleagues within the subdiscipline. His leadership sustained the field of paleobotany nationally, and he enriched it immeasurably by his contributions in strengthening the collegial network of internationally cooperative paleobotanists.
Tom’s numerical statistics are consistent with his stature in paleobotany. He won numerous awards during his career, including the prestigious Alexander von Humboldt Senior Research Award and the Botanical Society of America’s Merit Award (its highest honor), and was appointed to the National Science Board by President George W. Bush in 2006. Tom was awarded sixty National Science Foundation grants throughout his career. His publications included 468 peer-reviewed journal articles (many in Science, Nature, and the Proceedings of the National Academy of Sciences) and four major textbooks. He mentored twenty-five students for master’s and Ph.D. degrees and oversaw twenty-seven postdoctoral students. In addition, his laboratory was an incredibly active crossroads for national and international paleobotanists, and he hosted twenty-six scientists as visiting faculty members during his career. He was equally active in community service.
Jack Wittry writes of R. kidstonii on page 133 of "A Comprehensive Guide to the Fossil Flora of Mazon Creek".
Radstockia kidstonii Taylor, 1967
1958. Radstockia sphenopteroides (non Kidston); Langford: p. 284, figs. 524, 526 +3c, 528 За
1963. Crossotheca sp. Langford: pp. 216-218, figs. 830, 830a, 831, 831a, 834, 834a, 836, 836a
1967. Radstockia kidstonii Taylor: p. 43, pls. 6, 7
1969. Radstockia kidstonii Taylor; Darrah: p. 159, pl. 20, fig. 3; (?) pl. 21, fig 1DESCRIPTION: The penultimate and ultimate rachises are straight and longitudinally striated. The ultimate pinnae are lanceolate, free at the margins, and alternate. They have up to 15 alternating and deeply lobed pinnules along the sides. The pinnules are constricted at the base, and the lobes have a single lateral vein. The sori are uniform in size and elliptical: 2 mm long and 1 mm wide. They are partially embedded and hang from the lower surfaces of the pinnules. A longitudinal groove appears to divide the entire structure. Arising at right angles from the center cleft are smaller furrows that make the structure appear segmented. The isolated spores correspond to the genus Punctatisporites (Balme, 1995).
REMARKS: Radstockia kidstonii is very rare. Many examples of R. kidstonii appear similar to Crossotheca, but, unlike it, Radstockia has multiple sori attached to the bottom of a single pinnule. The pinnules are rarely visible in fertile examples. The affinities of R. kidstonii are not completely agreed upon at this time. When described, it was considered to be a true fern. Morphologically, the pinnules and fertile structures of R. kidstonii are very similar to those of the modern fern Marattia alata. Despite this, it is thought (Brousmiche, 1983) to have closer affinities to Crossotheca, a pollen-producing organ of a seed fern (Taylor et al., 2009).
George Langford mentions Radstockia sphenopteroides on page 284 in "The Wilmington Coal Flora From a Pennsylvanian Deposit in Will County Illinois".
RADSTOCKIA, Kidston.
This genus is similar to Hymenotheca with the exception that the sporangium is marked like a grid with short transverse grooves.
3. Radstockia sphenopteroides. Kidston. This genus and species were founded on a single speсimen. The sporangia are attached to the midrib in pairs, V shaped 3a. The transverse grooves on the sporangia are the distinguishing generic character, +3b., +3c.
We have specimens of this genus in two nodular halves, one half showing the longitudinal and transverse grooves on the sporangia, the other nodular half showing the longitudinal groove only.
Specimens
Field Museum PP 53618. This breathtaking specimen was at ESCONI's Mazon Creek Fossil Day in 2024.
Field Museum PP 42574 in Wittry's book
