Toumarkine & Luterbacher (1985):
T. rohri is strongly spinose, especially on the umbilical shoulders and around the peripheral margin and has a flattened spiral side. Bronnimann & Bermudez (1953) described, together with the species rohri, three varieties:
T. rohri var. guaracaraensis (Fig. 32.12), T. rohri var. piparoensis (Fig. 32.11), T. rohri var. mayoensis (Fig. 32.10). They differ from each other by the shape of the chambers of the last whorl (completely rounded for guaracaraensis to angular for mayoensis), but they are linked by transitional forms which are difficult to distinguish. We retain only the species rohri. T. rohri has a rounder axial periphery than T. topilensis, T. libyaensis or T. haynesi. Its chambers are less angular and increase more regularly in size. It differs from T. collactea in its larger size, and the more spinose and less compact test.
Bolli (1957):
In addition to Truncorotaloides rohri, Bronnimann and Bermudez (1953) described three varieties of this species which illustrate the variation of chamber and test shape ranging from rounded to angular forms. In T. rohri var. guaracaraensis are included specimens with spherical chambers. T. rohri var. piparoensis is an intermediate form between T. rohri var. guaracaraensis and T. rohri. The chambers of T. rohri var. mayoensis are angular conical, the test umbilicoconvex. This variety may be regarded as related to T. topilensis (Cushman). |
Brönnimann,P. and Bermudez,P.J. (1953):
Truncorotaloides, a new foraminiferal genus from the Eocene of Trinidad, B.W.I . Journal of Paleontology Vol. 27(6) p. 817-820
Beckmann,J.P. (1953):
Die Foraminiferen der Oceanic Formation (Eocaen-Oligocaen) von Barbados, Kl. Antillen . Ecoglae geologicae Helvetiae Vol. 46 p. 301-412
Bolli,H.M.; Loeblich,A.R. and Tappan,H. (1957):
The Planktonic foraminiferal families Hantkeninidae, Orbulinidae, Globorotaliidae, and Globotruncanidae . U.S. National Museum Bull. Vol. 215 p. 3-50
Bolli,H.M. (1957):
Planktonic Foraminifera from the Eocene Navet and San Fernando formations of Trinidad, B.W.I. . Bull. U.S. natl. Mus. Vol. 215 p. 155-172
Toumarkine,M. and Luterbacher,H.P. (1985):
Paleocene and Eocene Planktic Foraminifera.
In: Plankton Stratigraphy p. 87-154
Van Eijden,A.J.M. and Smit,J. (1991):
Eastern Indian Ocean Cretaceous and Paleogene quantitative biostratigraphy.
In: Proceedings of the Ocean Drilling Program, Scientific Results Vol. 121 Eds: Weissel, J.Peirce, J.Taylor, E.Alt, J. p. 77-123
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