Ticinella eubejaouaensis Randrianasolo & Anglada 1998 from: Moullade, M.Bellier, J.P.Tronchetti, G. (2002): Hierarchy of criteria, evolutionary processes and taxonomic simplification in the classification of Lower Cretaceous planktonic foraminifera . Cretaceous Research Vol. 23 p. 111-148 | . |
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Species Ticinella eubejaouaensis Randrianasolo & Anglada 1998 |
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| Discussion / Comments: |
Bellier & Moullade (2002):
Clarification of the status of T. bejaouaensis was
recently provided by Randrianasolo and Anglada
(1998), who pointed out that Sigal's holotype and paratype came from two different localities with different
ages :
- the holotype of Ticinella roberti var. bejaouaensis
SIGAL, 1966 (pl. 5, fig. 5-7) was chosen
from a depth of 215.2 m in the Diego Suarez well,
northern Madagascar. This level was thought to be of
late Aptian age by Sigal (1966) but was subsequently
demonstrated as being late Albian (Ramlrianasolo,
1989);
- the paratype (pl. 5, fig. 8-9) comes from Djebel
Bejaoua, Tunisia (upper Aptian-lower Albian).
Sigal's (1966) initial diagnosis of T. beiaouuensis
was emended by Moullade (1966) on the basis of a
comparative study of upper Albian topotypes of T.
roberti from the Breggia River section with T. bejaouaensis
and T. roberti from continuous Voeontian
basin sections of Aptian and Albian age. According to
Moullade, T. roberti (cf. pl. 1, fig. 19-21) has a thicker
test anti more protruding chambers; it is slightly
larger in lateral view; its wall texture and perforations
are rougher, as in Biticinella breggiensis (Gandolfi,
1942); the umbilicus is deeper and narrower;
the "Rotalipora-like"supplementary apertures are
much more distinct; and finally, the decrease of the
last whorl ornamentation is more progressive. Moullade
(1966) also defined the stratigraphic range of T.
bejaouaeusis as Clansayesian [=latest Aptian] to earliest
Albian. On the other hand, Moullade (1969),
and also Leckie (1984), suggested that T. bejaouaensis
and T. roberti may be two homeomorphic taxa.
In the northern Madagascar area, Randrianasolo
and Anglada (1998) confirm the middle Albian gap
between the T. bejaouensis and T. roberti morphotypes
discussed above. In addition to the morphological
features listed above, this strenghtens the hypothesis
of homeomorphy.
According to Randrianasolo and Anglada (1998) a
new species name is needed for the populations represented
by SigaFs (1966) paratypes. They propose
the name of T. eubejaouaensis for these upper
Aptian/lowermost Albian forms. Such an approach,though taxonomically correct, does not solve the problem
of the status and possible relationship between
the T. bejaouaensis s.s. = holotype forms) and T. roberti
concepts. For example :
1) is T. bejaottaensis sensu Randrianasolo and
Anglada (1998) an objective junior synonym of T. roberti
? This leads to the assmnption that Sigal (1966),
possibly influenced by the supposedly late Aptian/
early Albian age of the holotype level, mixed up a
specimen of T. roberti with his new variety; or
2) are T. bejaouaensis sensu Randrianasolo and
Anglada (1998) and T. roberti two (upper Albian)
distinct species ? |
| Synonym list: |
Moullade et al. (2002):
Bellier & Moullade (2002):
1974 Ticinella bejaouaensis Sigal. - Longoria : 94-95 (pars) pl. 18; fig. 1-2;
pl. 19, fig. 9-16;
pl. 21, fig. 12-13 (non pl. 21, fig. 9-11, 14-16)
? 1984 Ticinella roberti sensu lato Gandolfi. - Leckie : 600-601 (pars) pl. 5, fig. 5-12 (non pl. 5, fig. 1-4)
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| References: |
Sigal,J. (1966):
Le concept taxinomique de spectre. Exemples d’application chez les Foraminifères. Propositions de règles de nomenclature . Mémoires de la Société Géologique de France, Hors Série Vol. 3 p. 1-126
Moullade,M. (1966):
Etude stratigraphique et micropaléontologique du Crétacé inférieur de la "fosse vocontienne" . Documents des Laboratoires de Géologie de la Faculté des Sciences de Lyon Vol. 15 p. 1-369
Sigal,J. (1966):
Contribution à une monographie des Rosalines 1.Le genre Ticinella Reichel, souche des Rotalipores . Ecoglae geologicae Helvetiae Vol. 59 p. 185-217
Longoria,J.F. (1974):
Stratigraphic, morphologic and taxonomic studies of Aptian planktonic Foraminifera . Revista Espanola de MicropaleontologíaNo extraord p. 1-107
Leckie,M.R. (1984):
Mid-Cretaceous planktonic foraminiferal biostratigraphy off Morocco, Deep Sea Drilling Project Leg 79, Sites 545 and 547 . Initial Reports of the Deep Sea Drilling Project Vol. 79 p. 579–620
Randrianasolo,A. and Anglada,R. (1998):
About Ticinella roberti var. bejaouaensis Sigal, 1966 and Ticinella bejaouaensis Sigal emend. Moullade, 1966 Geological Congress.
In: Joint Regional Meeting of IGCP Projects nos 381 and 362, held in conjunction with the Cuban, Geologia y Mineria Vol. 2 p. 298
Bellier,J.P. and Moullade,M. (2002):
Lower Cretaceous Planktonik Foraminiferal Biostratigraphy Of The Western North Atlantic (ODP LEG 171B), And Taxonomic Clarification Of Key Index Species . Revue de Micropaleontologie Vol. 45(1) p. 9-26
Moullade,M.; Bellier,J.P. and Tronchetti,G. (2002):
Hierarchy of criteria, evolutionary processes and taxonomic simplification in the classification of Lower Cretaceous planktonic foraminifera . Cretaceous Research Vol. 23 p. 111-148
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