This is Mazon Monday post #197. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
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Palaeostachya sp. is a cone from a Calamites plant. It is very similar to Calamostachys (Mazon Monday #99), which are also cones from Calamites. Identification between the two can be difficult as the attachment point of the sporangiophores is often obscured.
Parts of a Calamites plant
The genus Palaeostachya was originally erected by Frederick Ernest Weiss (1865-1953) an Anglo-German botanist. He also described Calamostachys. While primarily a botanist, he worked extensively with coal-balls and published quite a few paleobotanical papers during his career at Owens College (later Victoria University of Manchester) in northern England.
William Crawford Williamson expanded upon Weiss' work in 1871 in the paper "A New Form of Calamitean Strobilus", which was published in the Memoirs of the Literary and Philosophical Society of Manchester. The paper was based on a "fragmentary calcified specimen" found by a Mr. Butterworth. The specimen was found in a nodule from the Upper Foot Coal at Roe Buck, in Strinesdale, Saddleworth near Manchester, England. In 1887, Williamson readdressed the description in "On the Organisation of the Fossil Plants of the Coal" with new better specimens from the Oldham district also near Manchester, England.
The systematic affinities of the Carboniferous Calamites have now been a moot question for close upon fifty years—the period that has elapsed since 1828, when, in bis ‘Prodrome d’une Histoire des Yegetaux Fossiles/ Adolphe Brongniart first suggested their relationships to the recent Equisetums. At this time nothing was known of examples of Calamites encased in a thick vascular cylinder; a product of the exogenous mode of growth resulting from the action of a camhial ring. At a later period Brongniart obtained such examples from Autun and elsewhere. But having then a conviction that no Cryptogamic stem could undergo an exogenous development, he concluded that two classes of plants had been comprehended in the genus Calamites; the one Equisetiform, to which he continued to give the old name, the other a Gymnospermous type, to which he assigned the name of Calamodendron. His well-merited influence led to a wide-spread acceptance of these views ; but their correctness began to be seriously questioned many years ago, on morphological grounds.
After a prolonged conflict the conclusions of those who insisted upon the Cryptogamic character alike of Calamites and of Calamodendron have met with an extensive, though not universal, acceptance. Meanwhile both the opposing schools of Palaeontologists recognise the importance of discovering the fructification of these plants. Mr. Carruthers believed that he had found it in examples of Calamostachys binneyanaf and Mr. Binney arrived at a similar conclusion.! I have always rejected these conclusions, because of the conspicuous differences between the morphology of the Calamitean twig and that of the axis of the Calamostachys. These differences appeared to me much too great to make it possible for the one ever to have been a prolongation of the other.
Palaeostachya appears on page 78 of Jack Wittry's "A Comprehensive Guide to the Fossil Flora of Mazon Creek".
Palaeostachya sp. Weiss 1876
1879-1880. Asterophyllites ovalis Lesquereux: p. 36, pl. 3, figs. 6, 7
1958. Palaeostachya. Langford: p. 52, figs. 72, 73
1969. Palaeostachya Weiss; Crookall: p. 761
1979. Palaeostachya. Janssen: p. 90, figs. 73a, 75DESCRIPTION: These cylindrical cones are very similar to Calamostachys. The major difference is that the sporangiophores connect directly to the bases of the sterile bracts.
REMARKS: Palaeostachya is rare. It is difficult to identify this taxon because the sporangiophores's attachment points are often obscured by the sterile bracts.
Specimens
From Wittry in "A Comprehensive Guide to the Fossil Flora of Mazon Creek".
From georgesbasement.com
From Wikipedia, Palaeostachya pedunculata
