This is Mazon Monday post #153. What's your favorite Mazon Creek fossil? Tell us at email:[email protected].
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Crookallia czernyshevi is a rare shark egg case. Until recently, it was known only from a site in Russia and another in Europe. Recently, Jack Wittry, author of a few Mazon Creek plant and animal books, tentatively identified a C. czernyshevi from Mazon Creek. The specimen was collected by ESCONI member Rob Coleman, who has alerted us of some rare specimens in the past. Rob found this beauty in a Pit 11 concretion collected a few years ago. This species is similar to Vetacasula, another rare Mazon species.
Crookallia czernyshevi is named for Robert Crookall (1890-1981), who was a British geologist and paleontologist. Crookall wrote numerous paper and books including "Fossil Plants of the Carboniferous Rocks of Great Britain" in 1955. That book completed earlier work by Robert Kidston, who died in 1924.
The international Organisation of Palaeobotany printed an obituary when he died in 1981.
OBITUARY
ROBERT CROOKALL 1890 1981
Dr Crookall died at his home town of Bath, England, on 2nd January 1981 after a heart attack.
He was born in Lancaster on 31st July 1890 and studied botany, chemistry and psychology at Bristol University. He stayed there to obtain his PhD from his studies on the Carboniferous flora of the Bristol and Somerset coalfields. He spent a year as a lecturer in botany at Aberdeen University before he was invited in 1924 to join the Geological Survey in South Kensington, London. He remained there until his retirement in 1952. He was initially employed by the Geological Survey as their first and only palaeobotanist, to finish the work of Robert Kidston who died in 1924. Kidston's collection of Coal Measure plant fossils and his manuscripts had been deposited with the survey and they needed to finish publishing his manuscript. In the event, no further parts appeared until three years after Crookall himself retired.
Crookall carried on his researches into Carboniferous plant distribution and published several papers on this topic while he was completing the Kidston manuscripts. He also published his useful little book of Coal Measure Plants in 1929.
Before retiring he began to return to his life-long interest in Psychical Research and Para-psychology. Since retiring we wrote a great many books on this subject and again received world wide recognition of his work. Robert Crookall was full of humour and was always helpful to those who needed it. He was a deeply religious man whose later publications and writings revealed his philosophy of attempting to show religious truths through scholarship and the scientific approach.
B.A. THOMAS, LONDON.
In the late 1920's, Crookall took a deep look at Carboniferous shark egg cases, then classified as enigmatic flower-buds or seed-vessels, and provided a comprehensive overview of all the species of Palaeoxyris, Fayolia and Vetacapsula known at the time. See page 80 of "Elasmobranch egg capsules Palaeoxyris, Fayolia, and Vetacapsula as subject of paleontological research - and annotated bibliography".
Between 1928 and 1932 R. Crookall provided a complete and comprehensive overview of all species of Palaeoxyris, Fayolia and Vetacapsula known at the time (Crookall, 1928a, 1928b, 1930, 1932). Furthermore, at the same time he revised and erected several new species (P. warei, P. pringlei, P. edwardsi, P. duni, P. bohemica, F. cambriensis, F. eltringhami, F. besti, F. warei, F. interstrialis, V. kidstoni, V. moyseyi, and V. hemingwayi). In Crookall (1932) the nature and affinities of these fossils were discussed in detail. First he listed 12 different groups to which Palaeoxyris and related genera Fayolia and Vetacapsula had been referred or with which they had been compared. He demonstrated that all remains invariably occur in fresh- or brackish water deposits; the capsules were attached to plants by their pointed beaks, and never showed cellular issue, which precludes them from being plant remains. Crookall came to the conclusion that they were of animal origin and had to be accepted as egg capsules of elasmobranchs. Furthermore, Crookall cited D. Watson’s remark about the shark family Hybodontidae, whose stratigraphical range covers exactly that of Palaeoxyris. With regard to Fayolia and Vetacapsula, other possible forms (Ichthyotomi, Petalodonttidae, Cochliodontidae, Cladontidae) were mentioned; their geological range, however, provided no assistance.
Specimens
Vetacapsula sp. from Crock Hey. Similar species.
Rob Coleman's Crookallia czernyshevi specimen from Pit 11.
Thanks for the suggestion, Rob!
