Praemurica taurica


Classification: pf_cenozoic -> Truncorotaloididae -> Praemurica -> Praemurica taurica
Sister taxa: P. uncinata, P. inconstans, P. pseudoinconstans, P. taurica, P. nikolasi, P. sp.,

Taxonomy

Citation: Praemurica taurica (Morozova 1961)
Rank: Species
Basionym: Globigerina (Eoglobigerina) taurica
Synonyms:
Taxonomic discussion: This is the first species of Praemurica to evolve from Hedbergella monmouthensis in the basal Danian. It is fairly commmon in Zone Pa. Although the cancellate wall texture is weakly developed, it is distinctive under SEM, being nearly identical to the living species Neogloboquadrina dutertrei. Praemurica taurica is a stem form of an important lineage leading to P. uncinata. [Olsson et al. 1999]

Catalog entries: Globigerina (Eoglobigerina) taurica

Type images:

Distinguishing features: 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. 

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.

Description


Diagnostic characters: The species is characterized by a very low trochospiral test with 5-6, occasionally more chambers in the ultimate whorl. The globular to slightly ovoid chambers increase very gradually in size with the last one or two occasionally slightly shifted towards the umbilicus. The umbilical-extraumbilical aperture is a low to high arch bordered by a narrow lip which broadens towards the umbilicus and becomes somewhat triangular in shape. In well preserved specimens the lips from previous chambers project as small flaps into a fairly wide and broad umbilicus which has a deep depression. The cancellate structure is weakly developed. [Olsson et al. 1999]

Character matrix

test outline:Subcircularchamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical-extraumbilical
sp chamber shape:Inflatedcoiling axis:Lowperiphery:N/Aaperture border:Thin lip
umb chbr shape:Inflatedumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Strongly depressedumb depth:Shallowwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:5.0-6.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Worldwide in the high to low latitudes (Figure 29). [Olsson et al. 1999]
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (1999)

Isotope paleobiology: Praemurica taurica has more positive ∂13C and more negative ∂18O than Subbotina and Globanomalina in the late Danian, but all these taxa have similar isotopic signatures in the earliest Danian (Berggren and Norris, 1997). There is a pronounced increase in ∂13C with increased size in P. taurica among small specimens (up to -200 urn; D'Hondt and Zachos, 1993) but a weak trend above this size (Norris, 1996). [Olsson et al. 1999]
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on δ13C lighter than species with symbionts; also with relatively light δ18O. Sources cited by Aze et al. 2011 (appendix S3): Berggren & Norris (1997); D'hondt & Zachos (1993)

Phylogenetic relations: This species evolved from Hedbergella monmouthensis in late Biochron P0. It is the stem form of the praemuricate pseudoinconstans -inconstans -uncinata lineage of the lower Paleocene (Danian) Zones Pl and P2. [Olsson et al. 1999]

Most likely ancestor: Praemurica nikolasi - at confidence level 5 (out of 5). Data source: Koutsoukos 2014, p.138.
Likely descendants: Praemurica pseudoinconstans;

Biostratigraphic distribution

Geological Range:
Notes: Upper Zone P0 to Zone Plb; ?Plc. [Olsson et al. 1999]
Last occurrence (top): in lower part of P1b subzone (30% up, 64.8Ma, in Danian stage). Data source: Olsson et al. (1999), fig. 5a
First occurrence (base): in mid part of P0 zone (50% up, 66Ma, in Danian stage). Data source: Olsson et al. (1999), fig. 5a

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 75

References:

Berggren, W. A. (1992). Paleogene planktonic foraminifer magnetobiostratigraphy of the southern Kerguelen Plateau (sites 747-749). Proceedings of the Ocean Drilling Program, Scientific Results. 551-568. gs

Morozova, V. G. (1961). Datsko-Montskie planktonnye foraminifery yuga SSSR [Danian-Montian Planktonic Foraminifera of the Southern USSR]. Paleontologicheskiy Zhurnal. 2(Aug-19): -. gs

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

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. gs


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Praemurica taurica compiled by the pforams@mikrotax project team viewed: 24-8-2019

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