''Mennerius'' is a genus of
haptophyte
The haptophytes, classified either as the Haptophyta, Haptophytina or Prymnesiophyta (named for '' Prymnesium''), are a clade of algae.
The names Haptophyceae or Prymnesiophyceae are sometimes used instead. This ending implies classification at ...
s belonging to the family
Lapideacassaceae.
Diagnosis
The genus accommodates ‘bell-shaped’ to cylindrical
nannoliths with their body consisting of one or more tiers of vertically elongated
calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...
plates and a rounded or somewhat pointed apical cone. One or more apical spines are often also present. The cross section of the body is round to polygonal.
Species
*''
M. asymmetricus''
(Perch-Nielsen in Perch-Nielsen & Franz, 1977)
*''
M. bispinosus''
(Perch-Nielsen in Perch-Nielsen & Franz, 1977)
*''
M. blackii''
(Perch-Nielsen in Perch-Nielsen & Franz, 1977)
*''
M. cornutus''
(Forchheimer & Stradner, 1973)
*''
M. glans''
(Black, 1971)
*''
M. longus''
Luljeva, 1967
*''
M. magnificus''
(Perch-Nielsen in Perch-Nielsen & Franz, 1977)
*''
M. mariae''
(Black, 1971)
*''
M. morosus''
Luljeva, 1967
*''
M. tricornus''
(Wind & Wise in Wise & Wind, 1977)
*''
M. trispinus''
(Perch-Nielsen in Perch-Nielsen & Franz, 1977)
*''
M. varius''
(Crux, 1981)
*''
M. wisei''
(Perch-Nielsen in Perch-Nielsen & Franz, 1977)
Distribution
The species of the genus occur sporadically but widely in the uppermost Lower and Upper
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
and
Palaeogene
The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...
sediments in the Northern Hemisphere, South Atlantic,
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
,
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...
and
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
.
References
Haptophyte genera
{{Haptophyte-stub