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
Taxonomy
Citation: Praemurica Olsson, Hemleben, Berggren,&Liu, 1992taxonomic rank: GenusType species: Globigerina (Eoglobigerina) taurica Morozova, 1961.Taxonomic discussion: Praemurica should probably be included in the Globigerinidae since Koutsoukos (2014) demonstrated that it was ancestral to both Eoglobigerina (and so Subbotina) and Parasubbotina. [editor's comment - JRY 2018]
The wall texture of Praemurica (Plate 6: Figures 2-4) is similar to that observed in the modern Neogloboquadrinadutertrei (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]
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;
NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They are being edited as the site is developed and comments on them are especially welcome.
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:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Primary source for this page: Berggren et al. 2006 - Eocene Atlas, chap. 12, p. 397
References:
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. gsO
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. gs
Praemurica compiled by the pforams@mikrotax project teamviewed: 13-10-2024
