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Dicarinella bouldinensis


Classification: pf_mesozoic -> Globotruncanidae -> Dicarinella -> Dicarinella bouldinensis
Sister taxa: D. asymetrica, D. bouldinensis, D. canaliculata, D. concavata, D. elata, D. hagni, D. imbricata, D. longoriai, D. primitiva, D. roddai, D. takayanagii,

Taxonomy

Citation: Dicarinella bouldinensis (Pessagno, 1967)
Rank: Species
Basionym: Marginotruncana bouldinensis
Taxonomic discussion: -Distorted test, makes it difficult to determine proper synonymy [copied from Chronos database]
Similar species: -Differs from M. marginata thinner, more compressed nature of tis test and by the flatened nature of its chambers spirally and umbilically. [copied from Chronos database]

Type images:

Original description: Marginotruncana bouldinensis Pessagno 1967: Test trochospiral, spiroconvex, with 4-5 chambers in last whorl. Chambers of spiral side crescent-shaped, individually somewhat planiform; earlier chambers somewhat rugose; sutures curved, raised, often beaded. Umbilical side of test slightly concave with rugosities sometimes present on first one or two chambers of last whorl; sutures radial, straight to slightly curved; chambers wedge-shaped; predominantly depressed. Umbilicus shallow and broad though somewhat variable in size. Periphery with double keel which seems to be better developed posteriorly than anteriorly. Primary aperture extraumbilical-umbilical in position. Portici with infralaminal accessory apertures on well-preserved specimens. Outer wall radial hyaline, perforate except for double keel which is radial hyaline imperforate. Septal wall microgranular hyaline, perforate. Portici microgranular hyaline perforate (?).

Entries in the Catalog of original descriptions: Marginotruncana bouldinensis;

Geological Range:
Last occurrence (top): within H. helvetica zone (92.56-93.52Ma, top in Turonian stage). Data source: [copied from Chronos database]
First occurrence (base): within W. archaeocretacea zone (93.52-94.03Ma, base in Cenomanian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

NB Plotting of Neptune data has been disabled on the Mesozoic pages because the dataset is both small and badly affected by a few sites with erroneous age models (our obs Huber, Petrizzo, Young, Nov 2016). The data can still be viewed via the range plottertool - tools menu.

Character matrix

test outline:Circularcoiling axis:Very lowchamber arrangement:Trochospiralumbilicus:Wide
edge view:Spiroconvexumbilical or test sutures:Strongly depressedspiral sutures:Raised beadedshell porosity:Microperforate: <1
wall texture:Smoothaperture:Umb.-extraumbilicalaperture border:Thin porticusaccessory apertures:Infralaminal
periphery:Double keelumb chamber shape:Crescenticsp chbr shape:Crescenticperiph margin shape:Subangular
umb depth:Shallowdiameter mm:width mm:breadth mm:
final-whorl chambers:4.0-5.0

References:

Pessagno, E.A., Jr., (1967). Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontograph. Americana, 5: 245-445.


Dicarinella bouldinensis compiled by the pforams@mikrotax project team viewed: 29-5-2017

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