Pseudopoulpus tenuihirsutus, Dumitrica & Zügel, 2003

Dumitrica, Paulian & Zügel, Peter, 2003, Lower Tithonian mono- and dicyrtid Nassellaria (Radiolaria) from the Solnhofen area (southern Germany), Geodiversitas 25 (1), pp. 5-72 : 34

Pseudopoulpus tenuihirsutus n. sp. ( Fig. 18E, G, H, J )

HOLOTYPE. — Photo No. 31417; stub Mue 22/4; Musée de Géologie , Lausanne, No. 74424 ( Fig. 18G ). ETYMOLOGY. — From the Latin tenuis: thin; and hirsutus: bristly.

MATERIAL EXAMINED. — Six specimens from the type horizon (sample Mue 22).

DIMENSIONS ( IN µM). — Total length 280-320 (av. 295), length of apical horn 25-105 (av. 60), of feet 95- 165 (av. 135), of secondary horns 35-85 (av. 55), of cephalis 110-135 (av. 125); total width 235-285 (av. 255), width of cephalis 125-150 (av. 140).

DESCRIPTION

Well rounded globular cephalis with three straight diverging feet and three or more secondary horns on the apical part. Apical horn and secondary horns long and thin, three-bladed at the base, rounded in cross-section, and curved in the median and distal parts. Ventral spine short, thin, and close to the base of cephalis. Cephalic base constricted, strengthened by an ovate basal ring formed of the arches VL, Ll, and Dl. Arches Al strongly pronounced on the inner side, connecting A and l below the apical part of the cephalis. Externally they are marked by a slight constriction and by a row of pores at the boundary with the slightly protruding dorsal lobe. Inside cephalic cavity D, V, and especially L bear small branched, spongy appendages which sometimes are so robust that they curve the bars. Feet slightly constricted at their bases, with maximum width in the median part. Grooves of feet narrow and deep; at the most proximal part additional shallow grooves may develop. Cephalic wall with irregularly arranged pores. Pores hexagonally or pentagonally framed, with small nodes at vertices which very rarely give rise to small thorns. Smaller pores especially in the centre of the dorsal lobe.

REMARKS

Pseudopoulpus tenuihirsutus n. sp. differs from the two species described by Takemura (1986) by having secondary horns on the apical part of the cephalis and a less inflated ventral part. From P. crassispinosus n. sp. it differs by the morphology of feet, apical horn and secondary spines. Whereas P. tenuihirsutus n. sp. gives a rather fragile impression, P. crassispinosus n. sp. is much more compact. Moreover, the dorsal lobe is more pronounced in the latter species.

Figures

FIG. 18. — A-D, I, Pseudopoulpus crassispinosus n. sp.; A, B, holotype, left lateral and basal views showing a thick spongy tissue around median bar, ventral spine, and primary lateral spines; C, D, I, paratypes; C, right lateral view; I, same, basal view showing details of initial spicule and arches; D, basal view showing an exagerate overgrowth of spongy tissue covering completely the colar aperture; E, G, H, J, Pseudopoulpus tenuihirsutus n. sp.; E, J, paratype,partly broken specimen, ventro-apical view, and detail of the dorsal lobe with arches Al; G, holotype, dorsal view showing the slightly pronounced dorsal lobe; H, paratype with a large number of additional horns, left lateral view; F, Pseudopoulpus spinosus Kiessling, 1999, right lateral view showing a pronounced dorsal lobe. Abbreviations: A, apical spine; l, secondary lateral spine. Scale bars: 30 µm.