pforams@mikrotax - Dicarinella canaliculata

Citation: Dicarinella canaliculata (Reuss 1854)

Taxonomic discussion: M. canaliculata (Reuss) has been one of the most frequently misidentified species of planktonic Foraminifera in the Upper Cretaceous (see synonymies of Globotruncana linneiana (dOrbigny) and Globotruncana lapparenti s.s. Brotzen) and has long served as a "waste basket" term for a number of double keeled species of Globotruncana and Marginotruncana.
The problem of the specific identity of Rosalina canaliculata Reuss is made complex by virtue of the fact that Reuss (1854, pi. 26, figs. 4a-b) only figured spiral and umbilical views of his type specimen and by virtue of the fact that the depository of Reusss type specimen is unknown after a period of over 110 years. It seems probable that Reusss type specimen of R. canaliculata is lost.
From Reusss descriptions (see Trujillo, 1961, p. 341) and figures it can be established that R. canaliculata possesses (1) a wide double keel; (2) petaloid to crescent-shaped chambers spirally; (3) a small umbilicus; and (4) wedged-shaped chambers umbilically.
To alleviate the taxonomic chaos surrounding this species, a neotype (PI. 74, figs. 5-8 herein) has been selected from the lower part of the Gosau beds of Edelbachgraben, Austria. Two samples from the lower part of the Gosau sequence were examined. One sample (G-19) (from W. W. Hay, Dept. Geology, University of Illinois) contains a well-preserved fauna in marls of Late Coniacian or Early Santonian age from Gosautal, Edelbachgraben. The following species were noted at this locality: Marginotruncana canaliculata (Reuss) abundant; M. marginata (Reuss) abundant; M. concavata (Brotzen)rare; Globotruncana lapparenti s.s. Brotzen common; Marginotruncana coronata (Bolli)common; M. pseudolinneiana Pessagno, n. sp.abundant.
The second sample (from Ruth Todd, U.S. Geol. Survey, Washington, D.C.) is from the type locality of Cythere sphenoides Reuss and contains a poorly preserved fauna in marls of Late Coniacian or Early Santonian age. It contains the same assemblage as cited above, but G. lapparenti is absent and M. canaliculata is rare. This locality occurs in marls in the lower part of the Gosau sequence and is undoubtedly the same horizon mentioned by Reuss (1854, pp. 7-8). Reuss (ibid.) noted that the marls of the lower Gosau beds are rich in ostracods and Foraminifera. His faunal lists (pp. 7, 8) include Cythere sphenoides Reuss, Rosalina canaliculata Reuss, Rosalina marginata Reuss and other species of Foraminifera and ostracods. As samples from both localities mentioned above include the same planktonic assemblage, it is likely that they came from about the same stratigraphic horizon in the lower part of the Gosau beds. Hagn (1957, p. 67) indicated that the Lower and Middle Gosau beds are of Coniacian to Early
Campanian age whereas the Upper Gosau is of Late Campanian age. Inasmuch as the first sample (G-19) noted above contains the best preserved material, a neotype3 is selected from this sample. [copied from Chronos database]

Original description: Test trochospiral, flattened spirally and umbilically; periphery truncated by wide double keel. Chambers arranged in two to two and one-half whorls; usually six to seven chambers in final whorl. Chambers in final whorl crescent-shaped to petaloid spirally, but distinctly wedge-shaped umbilically. Sutures on spiral side curved, slightly raised, usually not beaded; sutures on umbilical side straight, radial, depressed. Umbilical side of test often with coarse, beadlike, rugosities on chamber surfaces. Stout portici with infralaminal accessory apertures extending out into a small umbilicus. Primary aperture interiomarginal, extraumbilical in position, a slightly arched opening. Outer wall radial hyaline perforate except for double keel which is radial hyaline imperforate. Septal walls microgranular hyaline sparsely perforate. Portici microgranular hyaline probably sparsely perforate.

Geological Range:
Last occurrence (top): within D. asymetrica zone (83.65-85.60Ma, top in Santonian stage). Data source: [copied from Chronos database]
First occurrence (base): within H. helvetica zone (92.51-93.52Ma, base in Turonian stage). Data source: [copied from Chronos database]

References:

Falzoni, F., Petrizzo, M. R., Jenkyns, H. C., Gale, A. S. & Tsikos, H. (2016). 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. Cretaceous Research. 59: 69-97. gs

Huber, B. T., Petrizzo, M. R., Watkins, D. K., Haynes, S. J. & MacLeod, K. G. (2017a). Huber, B. T., Petrizzo, M. R., Watkins, D. K., Haynes, S. J. & MacLeod, K. G. (2017). Correlation of Turonian continental margin and deep-sea sequences in the subtropical Indian Ocean sediments by integrated planktonic foraminiferal and calcareous nannofossil biostratigraphy. Newsletters on Stratigraphy. 50: 141-185. Newsletters on Stratigraphy. 50: 141-185. gs

Reuss, A. E. (1854). Reuss, A. E. (1854). Beitrage zur Charakteristik der Kreideschichten in den Ostalpen, besonders im Gosauthale und am Wolfgangsee. Denkschriften der kaiserlichen Akademie der Wissenschaften zu Wien Mathematisch-Naturwissenschaftlichen Classe. 7: 1-156. Denkschriften der kaiserlichen Akademie der Wissenschaften zu Wien. 7: 1-156. gs O

Robaszynski, F., Caron, M. & le Groupe de Travail Européen des Foraminifères Planctoniques (1979). Robaszynski, F., Caron, M. & le Groupe de Travail Européen des Foraminifères Planctoniques (1979). Atlas des Foraminiféres Planctoniques du Crétace Moyen (Mer Boréale et Téthys). Cahiers de Micropaléontologie. 1 & 2: 1-185. Cahiers de Micropaléontologie. 1 & 2: 1-185. gs

test outline:	Circular	chamber arrangement:	Trochospiral	edge view:	Planoconvex	aperture:	Umbilical
sp chamber shape:	Inflated	coiling axis:	Very low	periphery:	Double keel	aperture border:	Thin porticus
umb chbr shape:	Inflated	umbilicus:	Narrow	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Strongly depressed	umb depth:	Shallow	wall texture:	Smooth	shell porosity:	Microperforate: <1µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	5-6	N.B. These characters are used for advanced search. N/A - not applicable

Dicarinella canaliculata

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