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Trichodinium chilense
From Fensome et al., 2019:
Trichodinium? chilense Troncoso and Doubinger, 1980, p.96–97, pl.1, fig.14.
Holotype: Troncoso and Doubinger, 1980, pl.1, fig.14.
Originally Trichodinium, subsequently (and now) Trichodinium?.
Questionable assignment: Jan du Chêne et al. (1986a, p.369).
Age: Maastrichtian–Danian.
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Original description: [Troncoso and Doubinger, 1980] (translated from Spanish):
Trichodinium chilensis sp. n.
Plate I, fig. 14.
Diagnosis: Oval to ellipsoidal body with a smooth surface, adorned with small spines all around. Spines no more than 7.5μ long, conic-acuminate in shape, with a rounded or bifid apex (in the latter case, one of the forks is longer than the other); the base of the spines is broad, often connected to the base of neighboring spines to form ridges. The cingulum is broad, 4-7μ long, indicated by a slight equatorial depression devoid of spines; its edges are regularly arranged and aligned with longer spines. The precingular archeopyle is clearly separated from the apical process and approximately 46-60μ long by 36μ wide. Apical process
Very well-differentiated, 18-27μ long; its edges bear small processes directed toward the apex; these processes may be spines identical to those on the rest of the body, simple filiform processes, branched processes, or membranous processes. The process itself is differentiated into two regions: a broad basal region (around 7μ), which reaches 30-40% of the total length of the process, and a thinner apical region. The apex of the process is slightly widened and truncated, with a small constriction immediately below the apex.
Holotype: SGO PmPb 1317/1 (R 43). Core 13, sample 1, between 1885-1887 m. Fuentes Formation, upper part.
Holotype measurements: μ long x 88μ (deformed), apical horn 18u long.
Dimensions: 60-μ long by 53-90μ wide (6 measurements).
Origin: Between 1600-2087 m, Strasbourg 8149-8155. Upper Fuentes Formation, lower Rocallosa Formation.
Observations: Specimens are often deformed along one of the two axes, in which case one axis clearly predominates over the other. Furthermore, the apical process often loses its extreme portion due to fracture.
Main material studied: Strasbourg 8149/2 (Q 29/4); Strasbourg 8150/2 (F 36/1); SGO PmPb 1317/2 (F 53/4).
Discussion and comparisons: Clarke and Verdier (1967) amended the genus Tricho dinium Eis. and Cook. 1960 to include forms with a precingular archeopyle, short hair sculpture, small spines or processes, and a small apical horn. Of the species described for the genus, its form most closely resembles T. intermediun Eis. and Cook. (later synonymized as T. castanea (Defl) Clarke and Verdier) from the Aptian-Albian of Australia; however, in our species the apical process is longer and the body ornamentation denser. The relationship with European and North American specimens of T. castanea appears to be more distant.
Trichodinium? chilense Troncoso and Doubinger, 1980, p.96–97, pl.1, fig.14.
Holotype: Troncoso and Doubinger, 1980, pl.1, fig.14.
Originally Trichodinium, subsequently (and now) Trichodinium?.
Questionable assignment: Jan du Chêne et al. (1986a, p.369).
Age: Maastrichtian–Danian.
---------------------------------------------------------------------------------------------------
Original description: [Troncoso and Doubinger, 1980] (translated from Spanish):
Trichodinium chilensis sp. n.
Plate I, fig. 14.
Diagnosis: Oval to ellipsoidal body with a smooth surface, adorned with small spines all around. Spines no more than 7.5μ long, conic-acuminate in shape, with a rounded or bifid apex (in the latter case, one of the forks is longer than the other); the base of the spines is broad, often connected to the base of neighboring spines to form ridges. The cingulum is broad, 4-7μ long, indicated by a slight equatorial depression devoid of spines; its edges are regularly arranged and aligned with longer spines. The precingular archeopyle is clearly separated from the apical process and approximately 46-60μ long by 36μ wide. Apical process
Very well-differentiated, 18-27μ long; its edges bear small processes directed toward the apex; these processes may be spines identical to those on the rest of the body, simple filiform processes, branched processes, or membranous processes. The process itself is differentiated into two regions: a broad basal region (around 7μ), which reaches 30-40% of the total length of the process, and a thinner apical region. The apex of the process is slightly widened and truncated, with a small constriction immediately below the apex.
Holotype: SGO PmPb 1317/1 (R 43). Core 13, sample 1, between 1885-1887 m. Fuentes Formation, upper part.
Holotype measurements: μ long x 88μ (deformed), apical horn 18u long.
Dimensions: 60-μ long by 53-90μ wide (6 measurements).
Origin: Between 1600-2087 m, Strasbourg 8149-8155. Upper Fuentes Formation, lower Rocallosa Formation.
Observations: Specimens are often deformed along one of the two axes, in which case one axis clearly predominates over the other. Furthermore, the apical process often loses its extreme portion due to fracture.
Main material studied: Strasbourg 8149/2 (Q 29/4); Strasbourg 8150/2 (F 36/1); SGO PmPb 1317/2 (F 53/4).
Discussion and comparisons: Clarke and Verdier (1967) amended the genus Tricho dinium Eis. and Cook. 1960 to include forms with a precingular archeopyle, short hair sculpture, small spines or processes, and a small apical horn. Of the species described for the genus, its form most closely resembles T. intermediun Eis. and Cook. (later synonymized as T. castanea (Defl) Clarke and Verdier) from the Aptian-Albian of Australia; however, in our species the apical process is longer and the body ornamentation denser. The relationship with European and North American specimens of T. castanea appears to be more distant.