Lapideacassis
Classification: ntax_mesozoic -> Nannoliths inc sedis -> Lapideacassaceae -> Lapideacassis
Sister taxa: Lapideacassis
Distinguishing features: Large hemispherical to tall cylindrical nannoliths with narrow walls constructed from one to several cycles of thin elements, enclosing a hollow central space; the nannolith tapers distally, and may have apical spines or processes. Protruding ledges often mark the junction of different cycles in the wall.
Daughter taxa (time control age-window is: 0-800Ma) |
 |  |  |  | Lapideacassis asymmetrica
Single spine, offset from centre (hence asymmetrica)
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 |  |  | | Lapideacassis bispinosa
Lapideacassis with two apical spines, one near-vertically orientated and one at 45 degress.
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 |  |  |  | Lapideacassis cornuta
Lapideacassis with two, apical spines at about 45 degrees.
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 |  |  |  | Lapideacassis glans
Squat, dome shaped Lapideacassis with protruding ledge just above the base.
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 |  |  |  | Lapideacassis magnifica
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 |  |  |  | Lapideacassis mariae
Tall, cylindrical Lapideacassis with tapering, curved upper part. Two or three cycles and ledges are typically present.
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 |  |  |  | Lapideacassis tricornus
Lapideacassis with three, near-vertically orientated, tapering apical spines.
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| | | | Lapideacassis trispina
Lapideacassis with three, near-horizontally orientated, tapering apical spines.
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 |  |  |  | Lapideacassis sp.
Specimens not identified to species level
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Taxonomy:
Citation: Lapideacassis Black, 1971Rank: GenusType species: Lapideacassis glans Black, 1971Synonyms: Scampanella Forchheimer and Stradner, 1973, Pervilithus Crux, 1981.
Farinacci & Howe catalog pages: Lapideacassis * , Scampanella + * , Pervilithus *
Distinguishing features: Large hemispherical to tall cylindrical nannoliths with narrow walls constructed from one to several cycles of thin elements, enclosing a hollow central space; the nannolith tapers distally, and may have apical spines or processes. Protruding ledges often mark the junction of different cycles in the wall.
Morphology: The genus name Scampanella Forchheimer and Stradner, 1973 has been used for Lapideacassis forms with a single wall cycle, but is regarded here as a junior synonym of Lapideacassis following Burnett (1997). The group in general has had many species named, based on the number of spines present, but this may be strongly influenced by preservation, rather than representing any real taxonomic significance. The L. mariae (tall) and L. glans (domed) types are most easily recognised.
Search data:
| Tags | LITHS: nannolith-radiate, circular, cylindrical, hollow, CA: process, closed, CROSS-POLARS: R-prominent, |
| Metrics | Lith size: 4->18µm; Segments: 6->14;
Data source notes: size range of included species |
The morphological data given here can be used on the advanced search page. See also these notes
Geological Range:
Last occurrence (top): at top of Priabonian Stage (100% up, 33.9Ma, in Priabonian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Aptian Stage (0% up, 126.3Ma, in Aptian stage). Data source: Total of range of species in this database
Plot of occurrence data:
- Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
- Triangles indicate an event for which a precise placement has been suggested
- Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Lapideacassaceae
References:
Black, M. (1971b). Problematical Microfossils from the Gault Clay. Geological Magazine. 108(4): 325-327. gs
Burnett, J. A. (1997c). New species and new combinations of Cretaceous nannofossils and a note on the origin of Petrarhabdus (Deflandre) Wise & Wind. Journal of Nannoplankton Research. 19(2): 133-146. gs V O
Crux, J. A. (1981). New calcareous nannofossil taxa from the Cretaceous of South East England. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte. 1981: 633-640. gs
Forchheimer, S. & Stradner, H. (1973). Scampanella, a new genus of Cretaceous nannofossils. Verhandlungen der Geologischen Bundesanstalt (Wien). 2: 286-289. gs V O
