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Muricohedbergella delrioensis


Classification: pf_mesozoic -> Hedbergellidae -> Muricohedbergella -> Muricohedbergella delrioensis
Sister taxa: M. almadenensis, M. angolae, M. astrepta, M. atlantica, M. blakensis, M. crassa, M. delrioensis, M. flandrini, M. hoelzli, M. holmdelensis, M. implicata, M. kyphoma, M. loetterli, M. monmouthensis, M. planispira, M. portsdownensis, M. praelibyca, M. rosebudensis, M. sliteri, M. wondersi, M. sp.,

Taxonomy

Citation: Muricohedbergella delrioensis (Carsey, 1926)
Rank: Species
Basionym: Globigerina cretacea delrioensis
Synonyms: Clavihedbergella globulifera; Rotundina ordinaria
Taxonomic discussion: The holotype of Globigerina cretacea var. delrioensis was not illustrated by Carsey (1926) has never been found. A neotype from the Del Rio Clay was identified by Longoria (1974) and deposited in the Smithsonian but was later lost. Masters (1976) subsequently declared a neotype that is stored in the USNM collections.
Petrizzo & Huber, 2006, JFR 36:185: The identity of H. delrioensis was the subject of many discussions as Carsey (1926) originally described this species from the Grayson Formation (Del Rio Clay), but failed to figure it and to designate the repository of the type specimens (Pessagno, 1967). In 1931, Plummer searched through the Carsey collection at the University of Texas and refigured some of Carsey's types but reported H. delrioensis missing. The lack of a type figure and type specimens to be referred to for comparison made the identification of H. delrioensis difficult. As a result, this species has been misidentified several times. A neotype for H. delrioensis was erected first by Longoria in 1974 and later by Masters in 1976. Both neotypes are deposited at the Smithsonian Museum of Natural History, Washington, D.C. with Longoria's neotype (USNM 184997) having priority, as was pointed out by Masters (1977). However, our re-examination of both type specimens revealed that Longoria's neotype has been lost and only the invalid neotype of Master (USNM 184813, see pl. 7, fig. 3a-c) remains deposited in the USNM collection.
At both Blake Nose sites we consistently found (1) common specimens of H. delrioensis very similar to the Master's neotype together with (2) very rare specimens that closely match Longoria's (1974) species concept (see pl. 7, figs. 4a-c). For this reason, and despite the problems arising from the loss of the valid neotype, we consider both neotypes to fall within the morphologic variability of the same species. [copied from Chronos database]

Type images:

Original description: Shell resembles that of G. cretacea except that the final chamber is more inflated and protrudes ventrally beyond the plane in which the foregoing part of the shell lies.

Entries in the Catalog of original descriptions: Globigerina cretacea delrioensis, Clavihedbergella globulifera, Rotundina ordinaria


Emended description: Petrizzo & Huber, 2006, JFR 36:185: Test low trochospiral, equatorial outline lobulate, peripheral margin rounded and slightly convex, wall macroperforate, test surface with irregularly distributed pustules more developed on the earlier chambers of the last whorl; chambers globular, 4 1/2 to 5 1/2 (rarely 6) increasing rapidly in size as added, last chamber often slightly offset towards the umbilical side; primary aperture a low umbilical-extraumbilical arch that extends on to the periphery, bordered by a flap; sutures radial and depressed on both sides. [copied from Chronos database]

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 P. appenninica zone (100.50-101.92Ma, base in Albian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Muricohedbergella delrioensis, synonyms included - Globigerina incretacea; Hedbergella delrioensis; Rotundina ordinaria;
  • space-time plot :: Samples map :: Parent: Muricohedbergella

    Character matrix

    test outline:Lobatechamber arrangement:Trochospiraledge view:Spiroconvexaperture:Umbilical-extraumbilical
    sp chamber shape:Globularcoiling axis:Lowperiphery:N/Aaperture border:Thin lip
    umb chbr shape:Globularumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:Relict
    spiral sutures:Moderately depressedumb depth:Shallowwall texture:Finely pustuloseshell porosity:Finely Perforate: 1-2.5µm
    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

    References:

    Carsey, D. O. (1926). Foraminifera of the Cretaceous of central Texas. University of Texas Bulletin. 2612: 1-56. gs

    Falzoni, F., Petrizzo, M. R., Jenkyns, H. C., Gale, A. S. & Tsikos, H. (2016). Planktonic foraminiferal biostratigraphy and assemblage composition across the Cenomanian–Turonian boundary interval at Clot Chevalier (Vocontian Basin, SE France). Cretaceous Research. 59: 69-97. gs

    Leckie, M. (1984). Mid-Cretaceous planktonic foraminiferal biostratigraphy off Central Morocco, Deep Sea Drilling Project Leg 79, Sites 545 and 547. Initial Reports of the Deep Sea Drilling Project. 79: 579-620. gs

    Petrizzo, M. R. & Huber, B. T. (2006). Biostratigraphy and taxonomy of late Albian planktonic foraminifera from ODP Leg 171B (western North Atlantic Ocean). Journal of Foraminiferal Research. 36: 166-190. gs


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    Muricohedbergella delrioensis compiled by the pforams@mikrotax project team viewed: 6-4-2020

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    Short stable page link: http://mikrotax.org/pforams/index.php?id=110364 Go to Archive.is to create a permanent copy of this page - citation notes



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