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Aireiana salicta
From Fensome et al., 2019:
Aireiana salicta, Damassa, 1979a, p.817–818, pl.1, figs.4–9; text-fig.2.
Holotype: Damassa, 1979a, pl.1, fig.4.
Age: Early-Middle Eocene.
Locus typicus: Costal Belt, Fransican Complex, California, USA
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Original description: Damassa, 1979, p. 817-818
Diagnosis:
Skolochorate cyst, ellipsoidal to spherical in shape, having fibrous intratabular processes formed by differentiation of outer part of autophragm. Processes tend to become fused in apical and sulcal regions. Paracingulum devoid of processes. Precingul ararcheopyle with rounded margin.
Description and dimensions:
Skolochorate cyst, ellipsoidal to spherical, overall diameter 54-60 µm, average = 56 µm, of eight specimens. Diameter of holotype = 57 µm. Wall consists of autophragm only. Total wall thickness 2-3 µm. Twelve to fourteen fibrous intratabular processes, 13-35 µm in length, formed by differentiation of outer part of autophragm.
Processes without a hollow interior. Processes tend to become fused in apical and sulcal regions. Longitudinal cross section of processes more or less rectangular; transverse cross section circular to irregular.
Paracingulum devoid of processes; parasulcal processes variably distinct, but anterior and posterior sulcal processes generally can be distinguished. Precingular, postcingular, and antapical processes large and generally well developed, although the first and second postcingular processes are fused with those of the parasulcus. Apex bears a single large process.
Archeopyle Type P, formed by loss of the third precingular paraplate. Margin of archeopyle rounded; operculum free.
Surface of cyst similar to processes in appearance, fibrous and highly perforate at the surface.
Process formula.--1", 5-6", 0c, xs, 4-5""", 1"""". Inferred thecal tabulation.--4", 6", 6c, xs, 1p, 6""", 1"""".
Affinities:
Aireiana salictum can be distinguished from A. verrucosa, the type species, by the length (13-35 vs. 6-10 µm, respectively) and fibrous nature of the processes (Stover, 1975). The number and shape of processes in the parasulcal region of A. salictum are highly variable. The sulcal paraplates are represented by an irregular mass from which several process tips arise. This group may include 1p, 1""", and 2""" as well. Clear indication of any paracingular processes is lacking in the specimens observed, although there is a possibility that they may be represented as irregular thickenings on the adcingular side of the postcingular processes. The four apical paraplates are represented by a process complex which may have a divided tip, indicating fusion of several processes. The antapical process tends to be tapered and terminally rounded, a feature which aids in specimen orientation. In contrast, distal surfaces of the large precingular and postcingular processes are roughly parallel to the surface of the cyst.
Aireiana salicta, Damassa, 1979a, p.817–818, pl.1, figs.4–9; text-fig.2.
Holotype: Damassa, 1979a, pl.1, fig.4.
Age: Early-Middle Eocene.
Locus typicus: Costal Belt, Fransican Complex, California, USA
---------------------------------------------------------------------------------------------------
Original description: Damassa, 1979, p. 817-818
Diagnosis:
Skolochorate cyst, ellipsoidal to spherical in shape, having fibrous intratabular processes formed by differentiation of outer part of autophragm. Processes tend to become fused in apical and sulcal regions. Paracingulum devoid of processes. Precingul ararcheopyle with rounded margin.
Description and dimensions:
Skolochorate cyst, ellipsoidal to spherical, overall diameter 54-60 µm, average = 56 µm, of eight specimens. Diameter of holotype = 57 µm. Wall consists of autophragm only. Total wall thickness 2-3 µm. Twelve to fourteen fibrous intratabular processes, 13-35 µm in length, formed by differentiation of outer part of autophragm.
Processes without a hollow interior. Processes tend to become fused in apical and sulcal regions. Longitudinal cross section of processes more or less rectangular; transverse cross section circular to irregular.
Paracingulum devoid of processes; parasulcal processes variably distinct, but anterior and posterior sulcal processes generally can be distinguished. Precingular, postcingular, and antapical processes large and generally well developed, although the first and second postcingular processes are fused with those of the parasulcus. Apex bears a single large process.
Archeopyle Type P, formed by loss of the third precingular paraplate. Margin of archeopyle rounded; operculum free.
Surface of cyst similar to processes in appearance, fibrous and highly perforate at the surface.
Process formula.--1", 5-6", 0c, xs, 4-5""", 1"""". Inferred thecal tabulation.--4", 6", 6c, xs, 1p, 6""", 1"""".
Affinities:
Aireiana salictum can be distinguished from A. verrucosa, the type species, by the length (13-35 vs. 6-10 µm, respectively) and fibrous nature of the processes (Stover, 1975). The number and shape of processes in the parasulcal region of A. salictum are highly variable. The sulcal paraplates are represented by an irregular mass from which several process tips arise. This group may include 1p, 1""", and 2""" as well. Clear indication of any paracingular processes is lacking in the specimens observed, although there is a possibility that they may be represented as irregular thickenings on the adcingular side of the postcingular processes. The four apical paraplates are represented by a process complex which may have a divided tip, indicating fusion of several processes. The antapical process tends to be tapered and terminally rounded, a feature which aids in specimen orientation. In contrast, distal surfaces of the large precingular and postcingular processes are roughly parallel to the surface of the cyst.