Back
Florentinia mantellii
Florentinia mantellii (Davey and Williams, 1966) emend. Davey and Verdier, 1973
Originally Hystrichosphaeridium, subsequently (and now) Florentinia.
Holotype: Davey and Williams, 1966, pl.6, fig.6
Locus typicus: Fetcham Mill, Surrey, England
Stratum typicum: Late Cenomanian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Florentinia mantellii (Davey and Williams, 1966b) Davey and Verdier, 1973, is distinguished by its rather regular arrangement of mainly simple and few distally bifurcating compound processes, one per plate. It has a relatively thin wall and combination 3" apical archeopyle. Apical operculum usually attached on ventral surface. Similar to F.radiculata, which is smaller, has more slender processes and more deeply divided, compound processes. The processes are open distally in F.mantellii and the postcingulars 2"-4" are very wide and distally may be bifurcate or give rise to a number of tubules. The antapical process is distinctively large, and lagenate; it is more or less convex distally and may bear small spines around the convexity.
--------------------------------------------------
Original description: Davey and Williams 1966, p. 66: Hystrichosphaeridium mantelli
Diagnosis: Spherical to sub-spherical central body composed of thin endophragm and granular or finely reticulate periphragm. Periphragm of processes slightly fibrous. Processes predominantly simple, tubiform, buccinate or bulbose, open distally with digitate or foliate margin. Occasionally narrow, solid, closed processes occur. Number of processes 26, or less, one process per paraplate area. Apical archaeopyle usually present.
Description: At first sight the periphragm of the central body appears to be fairly heavily granular, but on closer examination the granules apparently result from a fine reticulation. The processes are erect and extremely variable in form, being tubiform, buccinate or even bulbose, usually open but occasionally closed, and simple or branched distally. The closed processes are extremely narrow, less than 1Ám, and solid distally. An apical archaeopyle appears always to be present. The processes give a reflected tabulation of 6'', 6c, 5''', 1p, 1'''' and a variable number of sulcal processes, commonly 4-6. The detached apical region has not yet been identified.
Dimensions: diameter of central body: 36-45 Ám; length of processes: 13-26 Ám. 6 specimens measured.
Emended diagnosis: Davey and Verdier, 1973, p. 188: Florentinia mantelli
The central body is smooth to lightly granular, often more markedly granular beneath the processes, and bears regularly arranged, thin walled processes. They are hollow, tubular with faint longitudinal striations, usually open distally and with occasionally distal branches or tubules. A small apical boss may be present. The apical and cingular are relatively fine, with broad bases, taper distally and terminate with a small expansion or bifurcation. The precingular processes are similar only wider. The postcingular processes 2''', 3''' and 4''' are exceptionally wide and may be either simply bifurcate distally or may give rise to a number of tubules; process 5''' is smaller and process 1''', like the posterior intercalary process 1p, is even smaller, being of the apical process size. The sulcal processes are narrow and are either apparently elongate acuminate, deeply furcate or finely tubular. The antapical process is distinctly larger and lagenate; it is more or less convex distally and may bear small spines around the convexity. A precingular (3'') archaeopyle is only developed, although an incipient tear between the apical and precingular plates may be present.
Affinities:
Davey and Williams, 1966, p. 66: Hystrichosphaeridium mantelli
The reticulate nature of the central body and the fibrous processes differentiate H. mantelli from most other species. H. radiculatum is, however, fairly simlar but the processes are more deeply divided, there often being 2 to 3 sub-parallel branches, and narrower.
Davey and Verdier 1973, p. 188, 191: Florentinia mantelli
Florentinia mantelli is clearly related to F. deanei. The latter differs significantly in being larger, having more massive lagenate processes which are not branched and do not bear tubules, and finally in nearly always possessing a combintation archaeopyle (apical plates and precingular 3''). The specimen illustrated by Cookson and Eisenack 1968 shows very well the typical 'keyhole'-shaped archaeopyle. F. laciniata differs from F. mantelli by being larger and possessing more complex processes.
--------------------------------------------------------------------------------------------------------------------------------------------------
Remarks: Davey and Verdier 1976, p. 318: Florentinia mantellii
F. mantellii was redescribed in detail by Davey and Verdier (1973) and no additional morphological observations can be made. This species is recognized by its rather regular arrangement of mainly simple and few distally bifurcating compound processes, one per reflected plate area, its relatively thin wall and combination precingular 3"-apical archaeopyle. The apical operculum usually remains attached on the ventral surface. The similarity of F. mantellii to F. radiculata is discussed below. However, F. mantellii is now considered to be more closely related to F. deanei (Davey et Williams 1966) which does not possess compound processes but, like F. mantellii, does have a combination archaeopyle and marked variation in process size. In addition, F. deanei is generally larger and has more massive, and sometimes lagenate, processes.
Originally Hystrichosphaeridium, subsequently (and now) Florentinia.
Holotype: Davey and Williams, 1966, pl.6, fig.6
Locus typicus: Fetcham Mill, Surrey, England
Stratum typicum: Late Cenomanian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Florentinia mantellii (Davey and Williams, 1966b) Davey and Verdier, 1973, is distinguished by its rather regular arrangement of mainly simple and few distally bifurcating compound processes, one per plate. It has a relatively thin wall and combination 3" apical archeopyle. Apical operculum usually attached on ventral surface. Similar to F.radiculata, which is smaller, has more slender processes and more deeply divided, compound processes. The processes are open distally in F.mantellii and the postcingulars 2"-4" are very wide and distally may be bifurcate or give rise to a number of tubules. The antapical process is distinctively large, and lagenate; it is more or less convex distally and may bear small spines around the convexity.
--------------------------------------------------
Original description: Davey and Williams 1966, p. 66: Hystrichosphaeridium mantelli
Diagnosis: Spherical to sub-spherical central body composed of thin endophragm and granular or finely reticulate periphragm. Periphragm of processes slightly fibrous. Processes predominantly simple, tubiform, buccinate or bulbose, open distally with digitate or foliate margin. Occasionally narrow, solid, closed processes occur. Number of processes 26, or less, one process per paraplate area. Apical archaeopyle usually present.
Description: At first sight the periphragm of the central body appears to be fairly heavily granular, but on closer examination the granules apparently result from a fine reticulation. The processes are erect and extremely variable in form, being tubiform, buccinate or even bulbose, usually open but occasionally closed, and simple or branched distally. The closed processes are extremely narrow, less than 1Ám, and solid distally. An apical archaeopyle appears always to be present. The processes give a reflected tabulation of 6'', 6c, 5''', 1p, 1'''' and a variable number of sulcal processes, commonly 4-6. The detached apical region has not yet been identified.
Dimensions: diameter of central body: 36-45 Ám; length of processes: 13-26 Ám. 6 specimens measured.
Emended diagnosis: Davey and Verdier, 1973, p. 188: Florentinia mantelli
The central body is smooth to lightly granular, often more markedly granular beneath the processes, and bears regularly arranged, thin walled processes. They are hollow, tubular with faint longitudinal striations, usually open distally and with occasionally distal branches or tubules. A small apical boss may be present. The apical and cingular are relatively fine, with broad bases, taper distally and terminate with a small expansion or bifurcation. The precingular processes are similar only wider. The postcingular processes 2''', 3''' and 4''' are exceptionally wide and may be either simply bifurcate distally or may give rise to a number of tubules; process 5''' is smaller and process 1''', like the posterior intercalary process 1p, is even smaller, being of the apical process size. The sulcal processes are narrow and are either apparently elongate acuminate, deeply furcate or finely tubular. The antapical process is distinctly larger and lagenate; it is more or less convex distally and may bear small spines around the convexity. A precingular (3'') archaeopyle is only developed, although an incipient tear between the apical and precingular plates may be present.
Affinities:
Davey and Williams, 1966, p. 66: Hystrichosphaeridium mantelli
The reticulate nature of the central body and the fibrous processes differentiate H. mantelli from most other species. H. radiculatum is, however, fairly simlar but the processes are more deeply divided, there often being 2 to 3 sub-parallel branches, and narrower.
Davey and Verdier 1973, p. 188, 191: Florentinia mantelli
Florentinia mantelli is clearly related to F. deanei. The latter differs significantly in being larger, having more massive lagenate processes which are not branched and do not bear tubules, and finally in nearly always possessing a combintation archaeopyle (apical plates and precingular 3''). The specimen illustrated by Cookson and Eisenack 1968 shows very well the typical 'keyhole'-shaped archaeopyle. F. laciniata differs from F. mantelli by being larger and possessing more complex processes.
--------------------------------------------------------------------------------------------------------------------------------------------------
Remarks: Davey and Verdier 1976, p. 318: Florentinia mantellii
F. mantellii was redescribed in detail by Davey and Verdier (1973) and no additional morphological observations can be made. This species is recognized by its rather regular arrangement of mainly simple and few distally bifurcating compound processes, one per reflected plate area, its relatively thin wall and combination precingular 3"-apical archaeopyle. The apical operculum usually remains attached on the ventral surface. The similarity of F. mantellii to F. radiculata is discussed below. However, F. mantellii is now considered to be more closely related to F. deanei (Davey et Williams 1966) which does not possess compound processes but, like F. mantellii, does have a combination archaeopyle and marked variation in process size. In addition, F. deanei is generally larger and has more massive, and sometimes lagenate, processes.