Evolution in Monograptus priodon
- 1 October 1974
- journal article
- research article
- Published by Scandinavian University Press / Universitetsforlaget AS in Lethaia
- Vol. 7 (4) , 265-272
- https://doi.org/10.1111/j.1502-3931.1974.tb00902.x
Abstract
Biometric analysis of the Silurian graptolite M. priodon (Bronn) from Arctic Canada and the British Isles (UK) shows that the length of the sicula and the rhabdosome width at the level of theca 5 undergo a progressive increase from latest Llandoverian to late Wenlockian time. This change is attributed to sympatric evolution within the species. M. flemingii (Salter) may have evolved elsewhere from M. priodon stock and migrated later into the 2 regions. M. riccartonensis Lapworth probably ranges from latest Llandoverian through the Wenlockian, and may have been ancestral to the Ludlovian to Devonian Monograptus lineages.This publication has 2 references indexed in Scilit:
- Gene Flow and Population DifferentiationScience, 1973
- Graptolites from the Laforce and St. Léon Formations, Northern Gaspé, QuebecCanadian Journal of Earth Sciences, 1972