CATALOG OF ORIGINAL DESCRIPTIONS: Racemiguembelina Montanaro Gallitelli 1957

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.


Higher levels: pf_cat -> R -> Racemiguembelina
Other pages this level: Racemiguembelina, Radotruncana, Rectoguembelina, Riveroinella, Rosalina, Rosalinella, Rotalia, Rotalina, Rotalipora, Rotaliporinae, Rotundina, Rugoglobigerina, Rugoglobigerina (Archaeoglobigerina), Rugoglobigerina (Plummerella), Rugoglobigerina (Rugoglobigerina), Rugoglobigerinidae, Rugotruncana,

Daughter taxa (blue => in age window 0-300Ma)
= Racemiguembelina fructicosa
= Racemiguembelina powelli

Racemiguembelina

Citation: Racemiguembelina Montanaro Gallitelli 1957
Rank: Genus
Type species: Guembelina fructicosa Egger, 1900

Current identification/main database link: Racemiguembelina Montanaro Gallitelli 1957


Original Description
Diagnosis: Test calcareous, conical in shape; rarely planispiral in the early stage, later biserial, increasing regularly and equally in thickness and breadth, finally proliferated with a varying number of additional globular chambers, the last of which form a crown at the top of the test and are provided with a series of arcuate, basal apertures. No spiral arrangement of the adult chambers is evident. Ornamentation consists of longitudinally developed costae.

Etymology: The generic name comes from racemus, Latin, bunch or cluster of grapes+Guembelina, genus of Foraminifera; gender, feminine. The name refers to the later chamber proliferation as in a bunch of grapes, following an early development like Guembelina (=Heterohelix).

Extra details from original publication
Discussion: This genus includes species that develop a final chamber proliferation, giving rise to a conical test, such as have been placed in the genus Pseudotextularia Rzehak by various authors. As the emendation of the genus Pseudotextularia, earlier in the present paper, on the basis of its type species, P. elegans (Rzehak), restricts that genus to species which are biserial in the adult, with a lateral compression of the test in its later stages, the forms with chamber proliferation require a new generic assignment, and the present genus is proposed to fill that necessity.

As noted above, in the discussion of Pseudotextularia. specimens of this type were originally included with specimens of a biserial genus in Rzehak's description (1891, p. 2) of Cuneolina elegans, and later both forms were figured by Rzehak (1895) as Pseudotextularia varians.

Because Rzehak (1895) included in his synonymy of Pseudotextularia varians, the prior name Cuneolina elegans, he obviously considered them identical, hence the specific name varians must be suppressed as a junior synonym of elegans, as was later noted by Ellis and Messina (1940). It cannot be later resurrected for part of the group included therein by Rzehak. The biserial specimen of Rzehak (1895, pi. 7, fig. 1) was referred to the restricted Cuneolina elegans (=Pseudotextularia) by White (1929, p. 40), and is thus the lectotype of that species.

Cushman (1938, p. 22) considered Guembelina fructicosa Egger (misspelled as fruticosa) to be identical with Pseudotextularia varians. Thus the first valid name available for the proliferated form of Rzehak (commonly but erroneously referred to previously as Pseudotextularia varians), is fructicosa, and the correct name thus becomes Racemiguembelina fructicosa (Egger).

The enlargement of the test in Racemiguembelina produces a form which is circular or subcircular in transverse section. This circular section, together with the high degree of chamber proliferation in the mature stage, are characters, peculiar to this genus, which justify its separation from those forms with a completely biserial chamber arrangement and lateral compression.
If we do not consider as generic distinctions both these peculiarities—the conical enlargement and the final proliferation of the chambers, and accept within its range of variability the forms without proliferation and also those more or less compressed or extended, the majority of the globular-chambered Heterohelicidae couldbeplacedwithinasinglegenus. As there is no biological proof to confirm or deny the "natural" value of these characters in extinct forms, we must accept the morphological featmres of the test as a basis for a usable taxonomy, and the compressed biserial forms are here considered to belong to the genus Pseudotextularia, emended, whereas those with chamber proliferation belong to the present genus Racemiguembelina.
Although many authors cite a spiral arrangement of the chambers in this proliferated genus, none is visible either in their published figures nor in the types examined, hence this is discounted.

References:

Montanaro Gallitelli, E., (1957). A revision of the foraminiferal family Heterohelicidae. In: Studies in foraminifera; Part 1 - Planktonic foraminifera. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera: U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, D.C., pp. 133-154.


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Racemiguembelina compiled by the pforams@mikrotax project team viewed: 25-6-2018

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