Catalog - Paragloborotalia

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Paragloborotalia

Citation: Paragloborotalia Cifelli, 1982

Type species: Globorotalia opima opima Bolli, 1957.

Test trochoid, composed of about 2½ whorls with 4½ or more chambers in the peripheral whorl; flattened or slightly concave on the spiral side; profile rounded, periphery sublobulate to rounded; sutures broadly radial on both sides, depressed; aperture low, arched, umbilical to extraumbilical, sometimes lipped; wall coarse, spinose, honeycomb textured in the type species, with tiered ridges surrounding individual pores and spine bases protruding from ridge corners.

Remarks. In morphology and texture this genus corresponds to the original descriptions of Globorotalia Cushman and Turborotalia Cushman and Bermudez. However, as discussed above, Paragloborotalia cannot be reconciled with the type species of the above genera, either on phylogenetic, morphological or textural grounds. An Oligocene representative of Paragloburotalia belonging to the P. opima group probably was the globorotalid root stock from which Globorotalia developed in the middle Miocene. A connecting link between the two genera is seen in G. praescitula (Cifelli and Glacon, in press). However, a good link between Paragloborotalia and G . praescitula is yet to be found. Early Miocene representatives of Paragloborotalia such as the form Cifelli and Glacon (in press) identified as G. siakensis show no morphological or textural advancement over P. opima. Paragloborotalia is probably also ancestral to Neogloboquadrina, with divergence involving an almost entire loss of spinosity. A honeycombed ridge network is retained in Neogloboquadrina, but the ridges develop independently of spine bases. It is not known when the divergence may have occurred.
Modern homeomorphs of Paragloborotalia include Neogloboquadrina pachyderma and N . incompta which display the same morphological features. However, the textural affinities of these species are clearly allied with Neogloboquadrina, in their general lack of spinosity and their independently developed ridge network.

References:

Cifelli, R. (1982). Early Occurrences and some Phylogenetic Implications of Spiny, Honeycomb Textured Planktonic Foraminifera. Journal of Foraminiferal Research. 12(2): 105-115. gs

CATALOG OF ORIGINAL DESCRIPTIONS: Paragloborotalia Cifelli, 1982

Paragloborotalia

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			Paragloborotalia griffinoides Olsson & Pearson, in Olsson et al. 2006 = Paragloborotalia griffinoides
			Paragloborotalia lefkaraensis Hakyemez&Toker 2010