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Pyxidinopsis braboi
Pyxidinopsis braboi De Schepper et al., 2004, p.628,631, fig.6, nos.1–12.
Holotype: De Schepper et al., 2004, fig.6, nos.1–6.
Age: late early–early late Pliocene.
Original description (De Schepper et al., 2004)
Diagnosis: A small, spheroidal species of Pyxidinopsis Habib, 1976 bearing high (ca. 1.5–2.0 μm), relatively thick (0.3–0.5 μm), straight and sinuous muri that form an evenly distributed, nontabular microreticulation over entire surface. Lumina of microreticulation have small (ca. 0.3–0.5 μm) and large (ca. 0.5– 4.0 μm) diameters on same cyst. Surface of muri and lumina smooth. Thickness of pedium ca. 0.3 μm or less. Archeopyle precingular (1P), large; angles 2∧3 and 3∧4 slightly rounded. Operculum free.
Description: Small, spheroidal, proximate cysts; wall rigid with characteristic high (ca. 1.5–2.0 μm), irregular, complete or incomplete microreticulation over entire cyst surface. Lumina with small (ca. 0.3–0.5 μm) and large (ca. 0.5–4 μm) diameters occur on same cyst. Larger lumina dominate. Muri are relatively thick (0.3–0.5 μm) and of even height over entire cyst. Surface of muri and lumina smooth. Tabulation not reflected in lumen distribution. Homogeneous and smooth pedium up to about 0.3 μm thick, usually less. Archeopyle precingular (1P), iso-delta-camerate, formed by loss of plate 3″; ornamentation extends to archeopyle borders. Operculum free. Archeopyle sides 2–4 (sensu de Verteuil and Norris, 1996, text-fig. 21, p. 100) are slightly concave. Archeopyle sides 1 or 5 are reentrant near their midpoint (Fig. 6.3, 6.8). Angles 2∧3 and 3∧4 slightly rounded. No accessory sutures. Small apical protuberance (ca. 1.0 μm), involving both pedium and luxuria, observed on single specimen; not recognized on other specimens possibly due to cyst orientation. No other indications of tabulation. Cysts are susceptible to uptake of safranin-O stain.
Etymology: Named after the Roman soldier Silvius Brabo who killed the giant Druoon Antigoon, a fierce toll collector on the river Scheldt. He then cut off the giant's hand and threw it into the river. This action, according to legend, gave rise to the name of the city of Antwerp (ant = hand; werp = throw).
Type: Holotype, sample DGD 19, slide DGD 19, England Finder reference E53/2. Basal Shelly Unit, Lillo Formation, Deurganck Dock; upper Lower or lower Upper Pliocene. Figure 6.1– 6.6. Royal Belgian Institute of Natural Sciences, Brussels, registration number IRScN b4254.
Dimension: Holotype: maximum diameter, including luxuria, 40 μm; wall thickness, ca. 2.0 μm. Range: maximum diameter, 31(36.1)40 μm; wall thickness, 1.5–2.0 μm. Nine specimens measured.
Occurrence/ Strat. range: Basal Shelly Unit, Oorderen Sands and Kruisschans Sands members of the Lillo Formation at the Deurganck Dock; Basal Shelly Unit and Oorderen Sands Member at the Verrebroek Dock. Upper Lower and/or lower Upper Pliocene.
Discussion/Affinities: Pyxidinopsis delicata Wilson, 1988 differs from Pyxidinopsis braboi n. sp. in having a coarser reticulation with crenulate muri, larger overall size (overall diameter 51–62 μm for Pyxidinopsis delicata and maximum diameter 31–40 μm for Pyxidinopsis braboi), and thicker wall (ca. 2–4 μm for Pyxidinopsis delicata and ca. 1.5–2.0 μm for Pyxidinopsis braboi). Pyxidinopsis waipawaensis Wilson, 1988 differs in its coarser microreticulation and having a rounded pentagonal to quadrangular archeopyle bordered by a low ridge. Pyxidinopsis reticulata McMinn and Sun Xuekun, 1994 has ornamentation within the reticulum. Cerebrocysta? namocensis Head, Norris, and Mudie, 1989a has a 2P archeopyle. “Cerebrocysta powellii” Zevenboom and Santarelli (manuscript name in Zevenboom, 1995) is larger in size, has a coarser reticulation, and a thicker wall. “Cerebrocysta cassinascoensis” Zevenboom and Santarelli (manuscript name in Zevenboom, 1995) has a faintly microgranulate wall and large (5–10 μm) rectangular-shaped lumina.
Filisphaera filifera Bujak, 1984 emend. Head, 1994b differs in having a complete and finer microreticulation consisting of thinner septa (ca. 0.2 μm thick on Filisphaera filifera; 0.3–0.5 μm thick on Pyxidinopsis braboi), in having smaller lumina (maximum diameter 2.0 μm on Filisphaera filifera; up to 4.0 μm on Pyxidinopsis braboi), and in being larger (Filisphaera filifera, maximum diameter, 48–83 μm, Head, 1996b; Pyxidinopsis braboi, maximum diameter, 31–40 μm). Furthermore, Filisphaera filifera has an archeopyle with well-defined angles and in optical section the septa reveal a radially striate pattern. Filisphaera microornata (Head, Norris, and Mudie, 1989a) Head, 1994b differs in having finer septa, smaller lumina (maximum diameter of 2– 2.5 μm, but rarely up to 3.4 μm on Filisphaera microornata; up to 4 μm on Pyxidinopsis braboi) and in being larger (Filisphaera microornata, maximum diameter 49–65 μm; Pyxidinopsis braboi, maximum diameter, 31–40 μm).
Holotype: De Schepper et al., 2004, fig.6, nos.1–6.
Age: late early–early late Pliocene.
Original description (De Schepper et al., 2004)
Diagnosis: A small, spheroidal species of Pyxidinopsis Habib, 1976 bearing high (ca. 1.5–2.0 μm), relatively thick (0.3–0.5 μm), straight and sinuous muri that form an evenly distributed, nontabular microreticulation over entire surface. Lumina of microreticulation have small (ca. 0.3–0.5 μm) and large (ca. 0.5– 4.0 μm) diameters on same cyst. Surface of muri and lumina smooth. Thickness of pedium ca. 0.3 μm or less. Archeopyle precingular (1P), large; angles 2∧3 and 3∧4 slightly rounded. Operculum free.
Description: Small, spheroidal, proximate cysts; wall rigid with characteristic high (ca. 1.5–2.0 μm), irregular, complete or incomplete microreticulation over entire cyst surface. Lumina with small (ca. 0.3–0.5 μm) and large (ca. 0.5–4 μm) diameters occur on same cyst. Larger lumina dominate. Muri are relatively thick (0.3–0.5 μm) and of even height over entire cyst. Surface of muri and lumina smooth. Tabulation not reflected in lumen distribution. Homogeneous and smooth pedium up to about 0.3 μm thick, usually less. Archeopyle precingular (1P), iso-delta-camerate, formed by loss of plate 3″; ornamentation extends to archeopyle borders. Operculum free. Archeopyle sides 2–4 (sensu de Verteuil and Norris, 1996, text-fig. 21, p. 100) are slightly concave. Archeopyle sides 1 or 5 are reentrant near their midpoint (Fig. 6.3, 6.8). Angles 2∧3 and 3∧4 slightly rounded. No accessory sutures. Small apical protuberance (ca. 1.0 μm), involving both pedium and luxuria, observed on single specimen; not recognized on other specimens possibly due to cyst orientation. No other indications of tabulation. Cysts are susceptible to uptake of safranin-O stain.
Etymology: Named after the Roman soldier Silvius Brabo who killed the giant Druoon Antigoon, a fierce toll collector on the river Scheldt. He then cut off the giant's hand and threw it into the river. This action, according to legend, gave rise to the name of the city of Antwerp (ant = hand; werp = throw).
Type: Holotype, sample DGD 19, slide DGD 19, England Finder reference E53/2. Basal Shelly Unit, Lillo Formation, Deurganck Dock; upper Lower or lower Upper Pliocene. Figure 6.1– 6.6. Royal Belgian Institute of Natural Sciences, Brussels, registration number IRScN b4254.
Dimension: Holotype: maximum diameter, including luxuria, 40 μm; wall thickness, ca. 2.0 μm. Range: maximum diameter, 31(36.1)40 μm; wall thickness, 1.5–2.0 μm. Nine specimens measured.
Occurrence/ Strat. range: Basal Shelly Unit, Oorderen Sands and Kruisschans Sands members of the Lillo Formation at the Deurganck Dock; Basal Shelly Unit and Oorderen Sands Member at the Verrebroek Dock. Upper Lower and/or lower Upper Pliocene.
Discussion/Affinities: Pyxidinopsis delicata Wilson, 1988 differs from Pyxidinopsis braboi n. sp. in having a coarser reticulation with crenulate muri, larger overall size (overall diameter 51–62 μm for Pyxidinopsis delicata and maximum diameter 31–40 μm for Pyxidinopsis braboi), and thicker wall (ca. 2–4 μm for Pyxidinopsis delicata and ca. 1.5–2.0 μm for Pyxidinopsis braboi). Pyxidinopsis waipawaensis Wilson, 1988 differs in its coarser microreticulation and having a rounded pentagonal to quadrangular archeopyle bordered by a low ridge. Pyxidinopsis reticulata McMinn and Sun Xuekun, 1994 has ornamentation within the reticulum. Cerebrocysta? namocensis Head, Norris, and Mudie, 1989a has a 2P archeopyle. “Cerebrocysta powellii” Zevenboom and Santarelli (manuscript name in Zevenboom, 1995) is larger in size, has a coarser reticulation, and a thicker wall. “Cerebrocysta cassinascoensis” Zevenboom and Santarelli (manuscript name in Zevenboom, 1995) has a faintly microgranulate wall and large (5–10 μm) rectangular-shaped lumina.
Filisphaera filifera Bujak, 1984 emend. Head, 1994b differs in having a complete and finer microreticulation consisting of thinner septa (ca. 0.2 μm thick on Filisphaera filifera; 0.3–0.5 μm thick on Pyxidinopsis braboi), in having smaller lumina (maximum diameter 2.0 μm on Filisphaera filifera; up to 4.0 μm on Pyxidinopsis braboi), and in being larger (Filisphaera filifera, maximum diameter, 48–83 μm, Head, 1996b; Pyxidinopsis braboi, maximum diameter, 31–40 μm). Furthermore, Filisphaera filifera has an archeopyle with well-defined angles and in optical section the septa reveal a radially striate pattern. Filisphaera microornata (Head, Norris, and Mudie, 1989a) Head, 1994b differs in having finer septa, smaller lumina (maximum diameter of 2– 2.5 μm, but rarely up to 3.4 μm on Filisphaera microornata; up to 4 μm on Pyxidinopsis braboi) and in being larger (Filisphaera microornata, maximum diameter 49–65 μm; Pyxidinopsis braboi, maximum diameter, 31–40 μm).