Arkell.1956.Jurassic..

MADAGASCAR 339
No definitely Upper Kimeridgian fauna is known in Madagascar, but
at one locality, the rich Antsalova district, there is between the Virgatosphinctes
beds above and the Hybonoticeras beds below a horizon with
Uhligites spp., Haploceras elimatum and Hildoglochiceras kobelli (Besairie,
1936, p. 65).
MIDDLE KIMERIDGIAN
In the north at Antsalova and some other localities from 1 m. to 10 m.
of limestones have yielded numerous Hybonoticeras spp. and Aspidoceratids,
especially Physodoceras avellanoides (Uhlig), P. cf. cyclotum
(Oppel) and Metahaploceras (Besairie, 1936, pp. 64-5, pis. ix, x). This is
presumably also the level of Hemisimoceras spp. from Antsalova figured
by Spath (1925a, pp. 25-6 and plate).
LOWER KIMERIDGIAN
Only the upper part (Pseudomutabilis Zone) seems to be represented.
In the north there are limestones and marls with Aspidoceras of the
longispinum group and Pachysphinctes, typical Lithacoceras, Torquatisphinctes
and Taramelliceras, etc., underlain by marls with Nebrodites
(Besairie, 1936, pp. 64, 130-3, pis. ix, x). In the south the same zone is
widely represented by glauconitic and often oolitic limestone, but the
lowest Kimeridgian (Tenuilobatus Zone) is wanting there also (Basse,
1934. P- 7 1
)-
UPPER OXFORDIAN
Bimammatum Zone. There is as yet no evidence for the existence of
this zone in Madagascar.
Transversarium Zone (Plicatilis Zone). In the south-west the lower part
of this zone (at least) is represented at Ankazoabo (Nicolai, 1950, p. 149;
Collignon, 1949) by various Perisphinctes (Dichotomosphinctes) including
rotiformis Spath and jacobi Collignon, with P. aff. bocconii Gemmallaro,
Mayaites maya (Sow.) ('enormous specimens'), Euaspidoceras spp.
(unfigured) and various Phylloceratids. From the same beds, however,
are recorded other Euaspidoceras and Peltomorphites which indicate the
Cordatum Zone. These zones therefore seem to be here combined
as at Kwa Dikwaso, Tanganyika (see p. 328), whether by condensation
or mixing remains to be investigated. An Upper Oxfordian
Dichotomosphinctes is figured from the north-west by Besairie (1936, pi. viii,
fig. 15). Taramelliceras anar (Oppel) is also recorded (Basse, 1934, p. 67)
and a whole series of Mayaitids (Basse & Perrodon, 1952).
LOWER OXFORDIAN
Cordatum Zone. As just mentioned, elements of this zone such as
Peltoceras eugenii (Raspail), P. cf. bidens (Waagen), Euaspidoceras babeanum
(d'Orb.), E. aff. obesum (Spath), E. cf. nikitini Borissjak, are recorded from
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