Quiltyella nazcaensis


Classification: pf_cenozoic -> Globigerinidae -> Quiltyella -> Quiltyella nazcaensis
Sister taxa: Q. clavacella, Q. nazcaensis, Q. sp.,

Taxonomy

Citation: Quiltyella nazcaensis (Quilty, 1976)
Rank: species
Basionym: Clavigerinella nazcaensis Quilty, 1976
Synonyms:
Taxonomic discussion:

The type material from DSDP Site 320 is somewhat recrystallized, however areas of wall texture are exposed that indicate the presence of a bulloides-type wall and thus support an affiliation with Globigerinella. Quilty (1976) identified Clavigerinella akersi from the Eocene as the possible ancestor of Globigerinella nazcaensis. However, Clavigerinella has a weakly developed cancellate wall texture (Coxall and Pearson, 2006). Derivation of Clavatorella bermudezi from Q. nazcaensis, as suggested by Quilty (1976) is also unlikely on the grounds of wall texture differences. Clavatorella bermudezi possess a strongly cancellate, nonspinose wall texture whereas Q. nazcaensis appears to be related to Globigerinella. Although Quilty (1976) described the aperture of this species as lacking any rim or lip, reinvestigations of samples from Site 320 provided well-preserved specimens clearly showing a thick rim bordering the aperture.

Popescu and Brotea (1989) also recognized similarities between P. rohiensis and Q. nazcaensis, and identified potential differences only in the less incised sutures in the young stage, and relatively shorter radially elongated chambers. However, they included in the species Protentella rohiensis a large variability of morphologies, including specimens with radially elongated chambers, very similar to Quiltyella clavacella (see Popescu and Brotea, 1989, pl. I, figs. 4, 5), and specimens with only one or two radially elongated chamber more resembling G. clavaticamerata or G. molinae (see Popescu and Brotea, 1989, pl. I, figs. 11, 12 and 9, 10, respectively). While there may be a case to place at least some of Popescu and Brotea’s examples of P. rohiensis in Q. nazcaensis, we suggest this as an unnecessary complication, and currently untestable due to the lack of material. We thus regard all of the extreme elongated forms of P. rohiensis (Popescu and Brotea, 1989, pl. I, figs. 1, 2 and 4, 5) as Q. clavacella, while other less clavate forms (Popescu and Brotea, 1989, pl. I, figs. 7, 8 and 11, 12) are referred to G. clavaticamerata. [Spezzaferri et al. 2018]

Catalog entries: Clavigerinella nazcaensis

Type images:

Distinguishing features: Chambers strongly elongated, ending with spherical termination.

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:

Quiltyella nazcaensis is characterized by strongly elongated chambers, sharply ending with spherical knob-like termination. It is very fragile and easily broken, discrete digitate chambers are often the only part preserved of the entire specimens. [Spezzaferri et al. 2018]


Wall type: Normal perforate, spinose, bulloides-type wall structure. Pore concentrations average 160 pores/50 μm2 test surface area and pore diameters average 1.5-2 μm.

Test morphology: Test composed of 3 whorls, initially trochospiral, globigeriniform planispiral in the last whorl, 5-6 chambers are delicate, tube-like and strongly radially elongated and sharply developing a knob-like distal extremity, sutures straight and depressed in juvenile specimens, none clearly visible in adult specimens; aperture at the base of the last chamber interiomarginal but strongly tending to encompass the peripheral margin, a symmetrical arch, bordered by a distinct rim; in edge view chambers strongly elongated in shape. [Spezzaferri et al. 2018]

Size: Estimated maximum diameter of holotype 0.9 mm. Longest individual broken chamber 0.5 mm. [Spezzaferri et al. 2018]

Character matrix

test outline:Stellatechamber arrangement:Pseudoplanispiraledge view:Concavo-convexaperture:Extraumbilical-peripheral
sp chamber shape:Elongatecoiling axis:Very lowperiphery:N/Aaperture border:Thin lip
umb chbr shape:Elongateumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Shallowwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Moderately 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: Described from the southeastern Pacific Ocean. Inclusion of rohiensis as a junior synonym of Q. nazcaensis would extend the spatial range to the Paratethys region. [Spezzaferri et al. 2018]

Isotope paleobiology: No data available. The occurrence of Q. nazcaensis close to the eastern equatorial upwelling belt is consistent with observations on other Cenozoic digitate species, which show links with upwelling conditions (Coxall and others, 2007). [Spezzaferri et al. 2018]

Phylogenetic relations: We suggest this species evolved from Q. clavacella at the Zone O6/O7 transition in the upper Oligocene. [Spezzaferri et al. 2018]

Most likely ancestor: Quiltyella clavacella - at confidence level 3 (out of 5). Data source: Spezzaferri et al. 2018.

Biostratigraphic distribution

Geological Range:
Notes: Upper Oligocene Zone O6-O7 to Zone M1 in the lower Miocene. [Spezzaferri et al. 2018]
Last occurrence (top): within M1 zone (21.12-22.96Ma, top in Aquitanian stage). Data source: Spezzaferri et al. 2018
First occurrence (base): within O6 zone (25.21-26.93Ma, base in Chattian stage). Data source: Spezzaferri et al. 2018

Plot of occurrence data:

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.6 p.208

References:

Coxall, H. K. & Pearson, P. N. (2006). Taxonomy, biostratigraphy, and phylogeny of the Hantkeninidae (Clavigerinella, Hantkenina and Cribrohantkenina).. 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 8): 213-256. gs

Coxall, H. K., Wilson, P. A., Pearson, P. N. & Sexton, P. F. (2007). Iterative evolution of digitate planktonic foraminifera. Paleobiology. 33: 495-516. gs

Jenkins, D. G. & Orr, W. N. (1972). Planktonic foraminiferal biostratigraphy of the east equatorial Pacific--DSDP Leg 9. Initial Reports of the Deep Sea Drilling Project. 9: 1059-1193. gs

Popescu, G. & Brotea, D. (1989). Genus Protentella (Foraminifera) in North Transylvania Oligcene. In, Petrescu, I. (ed.) The Oligocene from the Transylvanian Basin. Cluj-Napoca 255-260. gs

Quilty, P. G. (1976). Planktonic foraminifera DSDP Leg 34, Nazca Plate. Initial Reports of the Deep Sea Drilling Project. 34: 629-703. gs

Spezzaferri, S., Coxall, H. K., Olsson, R. K. & Hemleben, C. (2018a). Taxonomy, biostratigraphy, and phylogeny of Oligocene Globigerina, Globigerinella, and Quiltyella n. gen. In, Wade, B. S. , Olsson, R. K. , Pearson, P. N. , Huber, B. T. & Berggren, W. A. (eds) Atlas of Oligocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication. 46(Chap 6): 179-214. gs


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Quiltyella nazcaensis compiled by the pforams@mikrotax project team viewed: 14-11-2019

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