Catalog entries: Velicucullus palaeocenica
Original description: Shell consists of a large cephalis and wide-based thorax. Cephalis indistinctly three-lobed, bearing a short threebladed apical horn. Cephalis sparsely perforated by subcircular pores without frames. External collar stricture rather distinct, internally with four collar pores. Cephalic structure has A, V, MB, two L, two 1 and D. Thorax flatly conical, expanded or discoidal, possessing many short spines or thorns on its distal margin. Thoracic pores subcircular, irregular in size; small on the top, rather large in the middle and then dense meshwork near the proximal part of the thorax with a delicate, slightly spongy inside brim.
(Based on 7 specimens) Height of cephalis and thorax 75-80 µ, of cephalis 55-56 µ, maximum width of cephalis 115-128 µ and maximum width of thorax 230-252 µ. Distinguishing characters (rw): This species is distinguished from Velicucullus magnificum (Clark and Campbell) by not having a definite velum or greatly expanded thorax. The forms which were studied here have rather shorter spines on the margin of the thorax than the specimens reported by Sanfilippo and Riedel (1973). Two kinds of thoracic margins are included: with or without spines. Specimens with a spiny margin appear in the uppermost part of the examined core section, while specimens without marginal spines occur in the lower part. The former occurs in two samples, 6-1 and 6-2.
Remarks on original description: The generic assignment of the species described below remains doubtful because it does not have a definite velum on the oral surface of the thorax.
Geological Range:
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:
References:
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Velicucullus palaeocenica compiled by the radiolaria@mikrotax project team viewed: 7-6-2023
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