Catalog - Pulvinulina menardii tumida Catalog - Pulvinulina menardii tumida

CATALOG OF ORIGINAL DESCRIPTIONS: Pulvinulina menardii var. tumida Brady 1877

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 -> P -> Pulvinulina -> Pulvinulina menardii tumida
Other pages this level: P. arca, P. arca contusa, P. crassata, P. crassata densa, P. gilberti, P. menardii fimbriata, P. menardii tumida, P. scitula, P. tricarinata, P. tumida flexuosa, P. velascoensis

Pulvinulina menardii tumida

Citation: Pulvinulina menardii var. tumida Brady 1877
taxonomic rank: variety
Type specimens: P. 44034. Lectotype designated by Banner & Blow 1960
Type age (chronostrat): Recent
Type locality: New Ireland (Territory of New Guinea), Bismarck Archipelago
Type repository: London, UK; NHM

Linked specimens: London, UK; NHM (44034) USNM-3143

Current identification/main database link: Globorotalia tumida (Brady, 1877)

Original Description

Description of lectotype: The large tumid test consists of about 17 chambers comprising 3 whorls of a moderately low trochospiral with 6 chambers in the last whorl. The number of chambers in each whorl increases slightly during ontogeny and they enlarge regularly but fairly slowly. As seen in dorsal aspect the chambers are initially reniform, becoming subquadrate in outline; they are little, if at all, inflated and are not embracing. In ventral aspect the chambers are sub-triangular, slightly inflated and partially embracing. The test is completely evolute dorsally but ventrally highly involute with a small but fairly deep umbilicus (which is partially infilled in lectotype). The equatorial profile is sub-circular and the equatorial periphery is smooth to weakly lobulate but becoming angular and sharply truncate in the terminal face. The axial profile is rhomboid, the test being almost equally biconvex. The axial periphery is acute and is furnished with an imperforate carina which is extremely massive on the early part of the last whorl becoming less strongly developed (although still well marked) on the terminal face. The dorsal sutures are slightly depressed but are distinctly thickened with clear shell material; these sutural deposits are continuous with, but appear thinner than, the material of the carina. The spiral suture is weakly lobulate; the dorsal intercameral sutures are initially smoothly curved but later become more sharply curved, their proximal ends being almost straight and nearly radial whilst their distal ends are re-curved almost tangentially to the periphery. The ventral sutures are not thickened but are depressed, and are weakly sinuous to nearly radial throughout. The primary aperture is interiomarginal, umbilicalforms comprising the "G. menardii" stock (compare extraumbilical, extending for about two thirds of the length of the basal suture; it is a low arch, partially covered by a distinct, uniformly broad, thick lip which appears to be a direct continuation of the chamber wall. The lip extends from the part of the aperture nearest the periphery almost to, but not quite reaching, the umbilicus, so that the inner part of the aperture is uncovered. The apertural face is, in apertural view, trapezoid in general outline; it is somewhat flattened and meets the ventral surface of the last chamber in a distinct hut rounded angle. The apertural face is limited dorsally by an extension of the carina and is slightly concave near it. The ventral surface of the last chamber is slightly concave near the periphery but becomes strongly convex towards the umbilicus thus forming a broadly rounded umbilical shoulder. It is, in part at least, this feature which gives the "'swollen," tumid appearance to the ventral surface of the test. The wall is calcareous, radial in structure, and uniformly and 'finely perforate except in the thickened dorsal sutures, the massive carina, and (possibly) ih the pustulose areas. The surface of the test is smooth except for the ventral surface of the early chambers of the last whorl and the umbilical margins of the later chambers; these areas are heavily pustulose. [Banner & Blow 1960]

Maximum diameter of lectotype: 0.75 mm. [Banner & Blow 1960]

Extra details from original publication

Taxonomic remarks: Brady first described this form from a fragment of soft, white calcareous rock which had been found by Liversidge on a beach on the east side of New Ireland (Territory of New Guinea), Bismarck Archipelago. Brady (1877, p. 535) also noted that he was aware of the presence of the same form in deep-sea dredgings collected during the voyage of H.M.S. Challenger, 1873-1876. However, we have selected the lectotype (here designated, described and illustrated, pl. 5, figs. la-c) from Brady's syntypic series obtained from the white "Chalk"" of New Ireland. The slide containing the syntypes is registered in the British Museum (Natural History) as number P. 43322 and was labelled in Brady's handwriting as follows: ""White Chalk, New Britain, Prof. Liversidge, Geol. Mag., Dec. 1877, p. 535;"" it is also labelled ""Pulvinulina menardii var. tumida, Post Tertiary, New Ireland"" with the same bibliographic reference. As in the case of Globigerina sacculifera Brady, there appears to have been some confusion in Brady's MS. as to the precise geographic origin of Liversidge's material, but this seems to have been corrected in Brady's published work.

The lectotype is now registered in the British Museum (Natural History) as specimen number P. 44034.

Bolli, Loeblich and Tappan (1957, p. 42, pl. 10, fig. 2) illustrated a ""syntype"" which they stated to be from the ""Post Tertiary"" of New Ireland; this specimen is now deposited in the U. S. National Museum as number P. 3143. If it be presumed that this specimen is actually a syntype, as stated by the authors, then it must have originated from Brady's original syntypic series which was deposited in the British Museum. Unfortunately, we have not been able to trace any record of a syntypic specimen having left the British Museum. The preservation of Brady's remaining syntypic specimens seems to be less good than that illustrated for Bolli, Loeblich and Tappan's specimen, although we have no doubt that the two forms are conspecific.

This species, Pulvinulina tumida Brady, was designated the type species of the genus Globorotalia Cushman 1927, by Cushman (1927) and used by him as the basis of his family Globorotaliidae (1927 and 1928). [Banner & Blow 1960]

Remarks: -The development of pustules on the ventral surface of the test varies greatly between individuals; the pustules of the lectotype are particularly strong (compare the specimen iliustrated by Bolli, Loeblich and Tappan, 1957). The pustules are developed on that part of the ventral surface which faces the primary aperture and which surrounds the umbilicus. This distribution of pustules is common to many rotaliform Foraminifera and is well known to occur in species of Amphistegina for example. Owing to the restricted distribution of these pustules it is considered here that they are secondarily formed on the walls of early chambers by protoplasmic flow from the aperture of the last formed chamber and possibly by similar protoplasmic flow, via the umbilicus, from relict parts of the primary apertures of earlier chambers. It is probable that this secondary deposition of calcareous material was responsible for the greatly thickened nature of the apertural lip and of the early parts of the carina, which is characteristic of the species. It is therefore possible that these pustules are due to a genetically inherited tendency to secrete more calcarBlow, 1959), reaching an apparent climax of development in Globorotalia tumida. This latter form is believed to have originated and separated from "" Globorotalia menardii"" sensu stricto in the Upper Tortonian and/or Lower Sarmatian. A parallel case is that seen in the Globorotalia fohsi Globorotalia lobata lineage (Bolli 1950, Banner and Blow 1959) within the Lower Miocene. Here, a small unkeeled form gave rise to a larger carinate form which, in turn, became more strongly carinate and robust until the lineage ended with Globorotalia lobata robusta (Bolli), which is a gross pseudomorph of Globorotalia tumida (Brady). However, Globorotalia lobata robusta (Bolli) differs from Globorotalia tumida (Brady) in possessing typically more chambers in the last whorl, these chambers being more narrowly triangular in ventral view and more sub-rectangular throughout in dorsal aspect; the dorsal intercameral sutures of G. lobata robusta are straighter and more nearly radially directed throughout. G. tumida is much more nearly equally biconvex possessing a greater dorsal convexity and a relatively less ventral convexity than is seen in G. lobata robusta.

Although G. tumida (Brady) and ""G. menardii"" are now clearly morphologically distinct and can be considered as separate species, in the Upper Tortonian and Sarmatian populations exist in which it is difficult to clearly separate the two forms. Many morphologically intermediate forms are present at this level indicating that during Upper Miocene times a gradual dichotomy took place leading to the separation of the two species (see text figure 2, and compare pp. 31 and 34-35). [Banner & Blow 1960]



Banner, F. T. & Blow, W. H. (1960a). Some primary types of species belonging to the superfamily Globigerinaceae. Contributions from the Cushman Foundation for Foraminiferal Research. 11: 1-41. gs O

Brady, H. B. (1877). Supplementary note on the foraminifera of the Chalk (?) of the New Britain group. Geological Magazine. 4(12): 534-536. gs


Pulvinulina menardii tumida compiled by the pforams@mikrotax project team viewed: 13-7-2024

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