pforams@mikrotax - Praemurica inconstans

Citation: Praemurica inconstans (Subbotina 1953)

Basionym: Globigerina inconstans

Synonyms:

Globigerina inconstans Subbotina, 1953:58, pl. 3: figs. 1, 2 [holotype,fig.1; both specimensfromzone of rotaliform globorotaliids, Elburgan Fm., Kuban River, northern Caucasus = middle part of Acarinina inconstans Zone of Leonova and Alimarina, I960],—Berggren, 1965:291, text-fig. 9:3, 4 [Zone P2, Mexia Clay member. Wills Point Fm., Midway Group, Mexia, Texas].
Globigerina schachdagica Khalilov, 1956:246, pl. 1:fig.3 [holotype: Danian Stage, Zeid, northwestern Azerbaidzhan].
Acarinina praecursoria Morozova, 1957:1111, text-fig. 1 [Danian, Khokodze River, northern Caucasus].
Globorotalia trinidadensis Bolli, 1957a:73, pl. 16: figs. 19-21 [holotype], figs. 22, 23 [Globorotalia trinidadensis Zone, lower Lizard Springs Fm., Trinidad],
Transitional form between Globorotalia pseudobulloides (Plummer) and Globorotalia uncinata Bolli.—Bolli, 1957a:74, pl. 17: figs. 16-18 [Globorotalia uncinata Zone, lower Lizard Springs Fm., Trinidad],
Globorotalia (Acarinina) inconstans (Subbotina).—Leonov and Alimarina, 1960, pl. 3: figs. 1-3, 5-8 [Globorotalia inconstans Subzone: figs. 1, 7, Podkhoomok River section; figs. 2-6, Khieu River; fig. 8, Urukh River, northern Caucasus].
Globigerina scabrosa Bermudez, 1961:1196, 1197, pl. 5: fig. 5 [Petromex Well, 200 m, La Palma 56, Panuco, Veracruz, Mexico],
Globigerina scobinata Bermudez 1961:1197, pl. 5: fig. 6 [Madruga Fm., Madruga, Havana Province, Cuba].
Globorotalia (Globorotalia) inconstans (Subbotina).—Hillebrandt, 1962:130, pl. 12: figs. 7, 8 [Zone B, Reichenhall-Salzburg Basin, Austro-German border].
Globorotalia inconstans (Subbotina).—Luterbacher, 1964:650: figs. 19-23 [figs. 19, 23, topotypes from zone of rotaliform globorotaliids, upper part of Elburgan Fm., Kuban River, northern Caucasus; figs. 20, 22, Globorotalia trinidadensis Zone, Gubbio section, central Apennines, Italy].
Globigerina arabica El-Naggar, 1966:157, 158, pl. 18: fig. 6 [holotype from Sample 30, Gebel Owaina, Globorotalia compressa/ 'Globigerina daubjergensis Zone, upper Danian, Nile Valley, Egypt],
Acarinina inconstans inconstans (Subbotina). —Shutskaya, 1970b: 108, pl. 6: figs. 4, 5 [middle part Acarinina inconstans Zone:fig.4, western Turkmenia, Malyi Balkhan;fig.5, Elburgan Fm., northern Caucasus].
Globorotalia (Turborotalia) inconstans (Subbotina).—Blow, 1979:1080, pl. 71: figs. 6, 7 [Zone Pl, DSDP Hole47.2/1/1: top], pl. 75:figs.4-7 [Zone Pl, Lindi area, Tanzania], pl. 76: figs. 3, 6, 7 [Zone P2, DSDP Hole 47.2/10/6: 69-71 cm],fig.10 [Zone P2, Hole 47.2/10/5: 70-72 cm], pl. 77:fig.1 [Zone P2, DSDP Hole 20C/6/4: 72-74 cm; Brazil Basin, South Atlantic Ocean], pl. 81: figs. 1, 2 [Zone P2, DSDP Hole 47.2/10/4: 83-85 cm; Shatsky Rise, northwestern Pacific Ocean], pl. 233: figs. 4, 5 [Zone Pl, Lindi area, Tanzania],
Subbotina inconstans (Subbotina).—Stott and Kennett, 1990:559, pl. 2:figs.5, 6 [Subzone APlb, upper Danian, ODP Hole 690C/14X72: 36-40 cm; Maud Rise, Weddell Sea, Southern Ocean].
Morozovella inconstans (Subbotina).—Berggren, 1992:564, pl. 1: figs. 12, 13 [Subzone Pic, ODP Hole 747A/19H/CC: Kerguelen Plateau, southern Indian Ocean]. [Olsson et al. 1999]

Taxonomic discussion: The extensive synonymy above reflects our current understanding and interpretation of this taxon. A variety of morphotypes have been ascribed to inconstans -trinidadensis -praecursoria over the past 40 years and assigned to the genera Globigerina, Globorotalia, Acarinina, Subbotina, and Turborotalia. We include this form in the genus Praemurica following the demonstration by Olsson et al. (1992) of a phylogenetically distinct and homogenous lower Paleocene cancellate, nonspinose lineage. One of us (W AB) has examined the type specimens of inconstans, praecursoria, trinidadensis, and schachdagica and the synonymic listing above is based to a large extent on those studies. The wide range of variation ascribed herein to this morphospecies unifies forms sharing the characteristics of a cancellate, nonspinose test intermediate between the pseudoinconstans -taurica morphology and the typically anguloconical, nonkeeled uncinata morphology. [Olsson et al. 1999]

Distinguishing features:
Parent taxon (Praemurica): Test very low trochospiral, usually 5-6, globular to oval chambers in last whorl, periphery lobulate;
Wall non-spinose, weakly cancellate;
This taxon: 5-7 chambered test; rapidly expanding final whorl; sutures radial; aperture an interiomarginal, umbilical-extraumbilical slit with distinct lipped rim.

Description

Biogeography and Palaeobiology

A cosmopolitan species in northern and southern hemisphere sections (Figure 28). [Olsson et al. 1999]
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (1999)

Praemurica inconstans has more positive δ13C and more negative δ18O than Subbotina and Globanomalina but has a similar isotopic signature to P. taurica (Boersma and Premoli Silva, 1983; Berggren and Norris, 1997). There is a pronounced increase in δ13C with increased size in P. inconstans (Kelley et al., 1996). [Olsson et al. 1999]
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on _¹³C lighter than species with symbionts; also with relatively light _¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Berggren & Norris (1997); Boersma & Premoli Silva (1983)

This morphospecies evolved from Praemurica pseudoinconstans by the development of umbilical-conical chambers in morphologically advanced forms, development of incised umbilical sutures, and an increase in the number of chambers in the final whorl. [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Zone Pic to lower Zone P3. [Olsson et al. 1999]
Last occurrence (top): near base of P3a subzone (10% up, 62.2Ma, in Danian stage). Data source: Olsson et al. (1999), fig. 5a
First occurrence (base): at base of P1c subzone (0% up, 63.9Ma, in Danian stage). Data source: Olsson et al. (1999), fig. 5a

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 73

References:

Berggren, W. A. (1965). Some Problems of Paleocene-Lower Eocene Planktonic Foraminiferal Correlations. Micropaleontology. 11: 278-300. gs

Berggren, W. A. (1992). Paleogene planktonic foraminifer magnetobiostratigraphy of the southern Kerguelen Plateau (sites 747-749). Proceedings of the Ocean Drilling Program, Scientific Results. 120: 551-568. gs

Bermudez, P. J. (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Editorial Sucre, Caracas. (3): 1119-1393. gs

Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs

Bolli, H. M. (1957d). The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 61-82. gs

Hillebrandt, A. , von (1962). Das Paleozän und seine Foraminiferenfauna im Becken von Reichenhall und Salzburg. Abhandlungen Bayerischen Akademie der Wissenschaften. 108: 1-182. gs

Khalilov, D. M. (1956). 0 pelagicheskoy faune foraminifer Paleogenovykh otlozheniy Azerbaydzhana [Pelagic Foraminifera of the Paleogene Deposits of the Azerbaizhan SSR]. Trudy Instituta Geologii, Akademiya Nauk Azerbaidzhanskoi SSR. 17: 234-255. gs

Leonov, G. P. & Alimarina, V. (1960). Stratigrafiya i planktonnye foraminifery "perekhodnykh" ot mela k paleogeny sloev tsentral'nogo Predkavkazya [Stratigraphy and Plantonic Foraminifera of the Cretaceous-Paleogene "Transition" Beds of the Central Part of the North Caucasus]. In Problema V: Granitsa melovoi i paleogenovoi sistem. Mezhdunarodnyi Geologicheskii Kongress, XXI Sessiya, Doklady Sovetskikh Geologov, Izdatelstvo Akademiya Nauk. 29-60. gs

Luterbacher, H. P. (1964). Studies in some Globorotalia from the Paleocene and Lower Eocene of the Central Apennines. Eclogae Geologicae Helvetiae. 57: 631-730. gs O

Morozova, V. G. (1957). On the Foraminiferal superfamily Globigerinidea, nov. and some of its representatives (in Russian). Doklady Akademii Nauk SSSR. 114(5): 1109-1112. gs

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs

Shutskaya, E. K. (1970b). Stratigrafiya, foraminifery i paleogeografiya nizhnego paleogena Kryma, predkavkaz'ya i zapadnoi chadsti srednei azii [Stratigraphy, Foraminifera and Paleogeography of the Lower Paleogene in the Crimea, Precaucasus and the Western Part of Central Asia]. Trudy Vsesoyuznego Neftyanogo Nauchno-Issledovatel'skogo Geologo-Razvedochnogo Instituta (VNIGRI). 70(1): 256-. gs

Soldan, D. M., Petrizzo, M. R. & Silva, I. P. (2014). Pearsonites, a new Paleogene planktonic foraminiferal genus for the broedermanni lineage. Journal of Foraminiferal Research. 44: 17-27. gs

Stott, L. D. & Kennett, J. P. (1990). The Paleoceanographic and Paleoclimatic signature of the Cretaceous/Paleogene boundary in the Antarctic: Stable isotopic results from ODP Leg 113. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 829-848. gs

Subbotina, N. N. (1953). Foraminiferes fossiles d'URSS Globigerinidae, Globorotaliidae, Hantkeninidae. Bureau de Recherches Geologiques et Minieres. 2239: 1-144. gs

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Inequally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Inflated	coiling axis:	Low	periphery:	N/A	aperture border:	Thin lip
umb chbr shape:	Inflated	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Strongly depressed	umb depth:	Shallow	wall texture:	Smooth	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	5-6	N.B. These characters are used for advanced search. N/A - not applicable

Praemurica inconstans

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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