Daughter taxa (time control age-window is: 0-800Ma) | ||||
Praemurica uncinata Plano-convex to moderately high spired, moderately lobulate test, 5-8 chambers in final whorl; sutures on spiral side incised and strongly recurved; axial periphery subangular, with rugose muricae; umbilicus typically narrow and deep | ||||
Praemurica inconstans 5-7 chambered test; rapidly expanding final whorl; sutures radial; aperture an interiomarginal, umbilical-extraumbilical slit with distinct lipped rim. | ||||
Praemurica pseudoinconstans Like P. taurica but with increased rate of expansion of the final few chambers; also apertural lip less pronounced. | ||||
Praemurica taurica Very low trochospiral test, 5-6 chambers in the ultimate whorl. Umbilicus fairly wide and broad. Aperture bordered by a narrow lip which broadens towards the umbilicus and becomes somewhat triangular in shape. | ||||
Praemurica nikolasi Very small trochospiral test, 4½–5 subglobular chambers in the last whorl; equatorial periphery lobate; ; very small umbilicus; last chamber inflated, with well-developed apertural lip projecting over the umbilicus and covering most of it. | ||||
Praemurica sp. Specimens which cannot be assigned to established species |
The wall texture of Praemurica (Plate 6: Figures 2-4) is similar to that observed in the modern Neogloboquadrina dutertrei (d'Orbigny) (Plate 5: Figures 9, 10). Elongate subparallel ridges, often with an orientation towards the aperture, are connected by shorter less well-developed ridges that are thicker and broader on one side. This gives the test a cancellate wall texture, which is herein termed praemuricate. It is the first distinctive nonspinose, pustulose wall texture to evolve in the phylogeny of the early Paleocene planktonic foraminifera. [Olsson et al. 1999]
Catalog entries: Praemurica
Distinguishing features:
Parent taxon (Truncorotaloididae): Muricate
This taxon: Test very low trochospiral, usually 5-6, globular to oval chambers in last whorl, periphery lobulate;
Wall non-spinose, weakly cancellate;
Most likely ancestor: Benthic foraminifera - at confidence level 3 (out of 5). Data source: Koutsoukos 2014.
Likely descendants: Eoglobigerina; Igorina; Morozovella;
plot with descendants
Geological Range:
Last occurrence (top): at top of P3a subzone (100% up, 61.3Ma, in Selandian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within P0 zone (66.00-66.04Ma, base in Danian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Primary source for this page: Berggren et al. 2006 - Eocene Atlas, chap. 12, p. 397
Berggren, W. A., Olsson, R. K. & Premoli Silva, I. (2006a). Taxonomy, biostratigraphy and phylogenetic affinities of Eocene Astrorotalia, Igorina, Planorotalites, and Problematica (Praemurica? lozanoi). In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 12): 377-400. gs Koutsoukos, E. (2014). Phenotypic plasticity, speciation, and phylogeny in Early Danian planktic foraminifera. Journal of Foraminiferal Research. 44: 109-142. gs Morozova, V. G. (1961). Datsko-Montskie planktonnye foraminifery yuga SSSR [Danian-Montian Planktonic Foraminifera of the Southern USSR]. Paleontologicheskiy Zhurnal. (2): 8-19. gs O Olsson, R. K., Hemleben, C., Berggren, W. A. & Liu, C. (1992). Wall Texture Classification of planktonic foraminifera genera in the Lower Danian. Journal of Foraminiferal Research. 22(3): 195-213. gsReferences:
Praemurica compiled by the pforams@mikrotax project team viewed: 3-11-2024
Short stable page link: https://mikrotax.org/pforams/index.php?id=100250 Go to Archive.is to create a permanent copy of this page - citation notes |