Catalog entries: Lophophaena auriculaleporis
Original description: Shell small, with two strong, forked, very prominent apical horns, the larger one usually subvertical, 0.5 total length, and the smaller, subhorizontal one 0.3 total length, the tips sharp, the horns both very stout (about 3°), equally four-bladed, the angles decurrent distally, strong basally, slightly twisted, the level of origin not especially modified as the horns arise directly from the cephalis, the horns well-separated (45° in some, and 90° in other, individuals); cephalis small, asymmetrical with the top higher on the side with the vertical horn, wide, apically the space between the horns flattened, sides expanded from top to base, the basal diameter twice the height, the height only about 0.12 total length; thorax truncate-ovate (40° in the upper part, later 10° and finally 30° in the contracted 0.25 of thorax), the sides very strongly convex, trim, apertural end truncated squarely, the diameter 0.3 total length, with a thin, subregular, rounded rim like the moulded edge of a metal pail, the rim slightly irregular as if torn along the free edge; wall mostly thin, a little thicker at the top of the cephalis than elsewhere, generally neat; surface of horns, hyaline; of cephalis, hyaline save a scattering of small, pimplelike dots; of thorax, with a great many circular pores of several sizes, the largest pores being near the middle, and the smaller ones irregularly scattered among them and below, the pores all well-spaced, no pores just above the apertural rim, but a regular row is found exactly above the rim; framework light.
Length of shell, 180µm; of horns, 87.0 and 45.2µm; respectively; of cephalis, 21.0µm; diameter of widest part of thorax, 76.0µm; of largest pores, 4.4µm. Distinguishing characters (rw): A small suite of individuals representing the common types in this collection is shown. The length of the horns and the relative amount of thoracic swelling are among the principal variable characters. The thorax also varies in length in several to a considerable degree. The most typical individuals are those figured in Figures 20 and 27.
Lophophaena auriculaleporis n. sp. is so unlike the other species of the subgenus to which it belongs that confusion of it with others is not likely to arise.
Last occurrence (top): within Paleogene Period (23.03-66.04Ma, top in Chattian stage). Data source: Lazarus et al. 2015 - "P age group"
First occurrence (base): within Paleogene Period (23.03-66.04Ma, base in Danian stage). Data source: Lazarus et al. 2015 - "P age group"
Plot of occurrence data:
Clark, B. L. & Campbell, A. S. (1942a). Eocene radiolarian faunas from the Mt. Diablo area, California. Geological Society of America, Special Papers. 39: 1-112. gs Petrushevskaya, M. G. & Kozlova, G. E. (1979b). Opisanie rodov i vidov radiolyariy. In Istoriya mikroplanktona Norvezhskogo Morya. Issledovanie Faunyi Morey (Akademii Nauk SSSR) Leningrad. 23(31): 86-157. gs O
Clark, B. L. & Campbell, A. S. (1942a). Eocene radiolarian faunas from the Mt. Diablo area, California. Geological Society of America, Special Papers. 39: 1-112. gs
Petrushevskaya, M. G. & Kozlova, G. E. (1979b). Opisanie rodov i vidov radiolyariy. In Istoriya mikroplanktona Norvezhskogo Morya. Issledovanie Faunyi Morey (Akademii Nauk SSSR) Leningrad. 23(31): 86-157. gs O
Artobotrys auriculaleporis compiled by the radiolaria@mikrotax project team viewed: 29-1-2023
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