CATALOG OF ORIGINAL DESCRIPTIONS: Turborotalia kotarduensis Mukhopadhyay 2005

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 -> T -> Turborotalia -> Turborotalia kotarduensis
Other pages this level: T. altispiroides, T. bannerblowi, T. bykovae, T. cambayensis, T. centralis perfecta, T. clemenciae, T. czeczvaensis, T. hirsutoides, T. kotarduensis, T. lata, T. munda franzenaui, T. pseudoampliapertura nukhulensis, T. pseudoampliapertura sinaiensis, T. pseudobesa, T. vagalkhodensis

Turborotalia kotarduensis

Citation: Turborotalia kotarduensis Mukhopadhyay 2005
Rank: Species
Type locality: About 0.5 km south of Dinod village. India
Type age (chronostrat): P18 Zone to P19, Early Oligocene
Type sample (& lithostrat): Sample number 53 in section line II, from yellow marl towards the upper part (pt-iv) of the Amravati Formation.
Type specimens: Pl. II, fig. 21 ; Pl. III, figs 10-13, 15, 16, 19.; Holotype : Figured specimen Pl. III, figs 9-12, Laboratory registration no T-25/55/98/II. Other material studied: Six specimens from sl. II and two from sl. I.
Type repository: Kolkata; Palaeontology Division, Geological Survey of India, 15, Kyd Street, Kolkata-700016, India

Current identification:


Original Description
Diagnosis : Unequally biconvex low trochospiral test, acute peripheral margin with thick perforate peripheral band, last chamber smaller than the penultimate one, sutures curved on ventral side, areal aperture on the ventral surface of the last chamber, surface coarsely perforated.
Description : Test medium, peripheral outline subcircular, weakly lobed, subtriangular in side view; dorsal side weakly convex, ventral strongly convex resembling asymmetric ʻvʼ with round apex ; peripheral margin acute with round tip; a thick perforate keel all along peripheral margin; spire tight comprising more than 2.5 whorls, early spire indistinct weakly raised, last whorl with four longer than high chambers markedly increasing till the penultimate one, last chamber smaller than the penultimate one; spiral suture in later part shallow ; septal sutures in last whorl radial nearly straight occurring almost at the level of chamber surface. In peripheral view the peripheral angle between dorsal and ventral sides is acute in the early part of the last whorl, gradually increasing with growth. On the ventral side early sutures indistinct, later sutures faint curved except for the basal suture of last chamber, which is nearly straight; sutures occurring almost at the level of the chamber surfaces; umbilicus closed. Aperture areal, an elongate opening on the ventral side of the last chamber in between its anterior part and the periphery, and oriented almost parallel to the basal suture, subelliptical in peripheral view, bordered by a raised perforated wall, subcircular in ventral view ; surface coarsely perforated ; sutures, peripheral margin and wall of the aperture with sparse coarse perforations ; pores vary in size and shape.

Etymology: After Kotardu nala, 1.5 km east of Dinod village in Surat Distri

Extra details from original publication
Remarks: Turborotalia kotarduensis n. sp. is the youngest keeled Turborotalia in the studied sequence. A little variation in it occurs in peripheral outline, sutures and perforations. This species resembles T. cunialensis and T. cambayensis in overall morphological characters including shape of test, smaller size of last chamber, strong peripheral keel and lack of umbilicus. However, in aerial aperture, large perforations throughout the test, indistinct ventral sutures and almost uniformly thick peripheral margin T. kotarduensis is distinct. The fine pore-like structures in the sutures and the arched peripheral aperture of T. cambayensis appear to have been replaced by coarse perforations and aerial aperture in T. kotarduensis to suggest a phyletic relationship in between.

Distribution
: Turborotalia kotarduensis is restricted to the Turborotalia kotarduensis Zone (P18 Zone to P19, Early Oligocene) in sl I & II.

References:

Mukhopadhyay, S. K. (2005). Turborotalia cerroazulensis group in the Paleogene sequence of Cambay Basin, India with a note on the evolution of Turborotalia cunialensis (Toumarkine & Bolli). Revue de Paléobiologie. 24: 29-50. gs V O


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Turborotalia kotarduensis compiled by the pforams@mikrotax project team viewed: 6-3-2021

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