radiolaria - rads_cenozoic - Actinomma golownini

radiolaria - rads_cenozoic - Actinomma golownini radiolaria - rads_cenozoic - Actinomma golownini

Actinomma golownini

Classification: rads_cenozoic -> Actinommidae -> Actinommidae (ss) -> Actinomma -> Actinomma golownini
Sister taxa: A. acusosum, A. arcadophorum, A. beroes, A. boreale, A. buspinigerum, A. campylacantha, A. capillaceum, A. delicatulum, A. golownini, A. haysi, A. henningsmoeni, A. holtedahli, A. kerguelenensis, A. leptoderma, A. livae, A. magnifenestra, A. medianum, A. mediterranensis, A. medusa, A. mirabile, A. plasticum, A. popofskii, A. sol, A. sphaerechinus, A. trinacria, A. yosii, A. sp.

A. golownini Site 751 dbl.jpg
rad_org Actinomma golownini, img2658.jpg

Taxonomy

Citation: Actinomma golownini Petrushevskaya 1975

taxonomic rank: species

Basionym: Actinomma golownini

Synonyms:
1975 Actinomma golownini - Petrushevskaya p. 569, pl. 2, fig. 1
1975 Actinomma tanyacantha Chen

From Suzuki Paleotax db:

1974 Actinomma tanyacantha n. sp. Chen p. 481-482, pl. 1, figs. 1, 2
1975 Actinomma golownini n. sp. Petrushevskaya p. 569, pl. 2, fig. 16
1975 Actinomma tanyacantha n. sp. [sic] Chen p. 450, 452, pl. 11, figs. 5, 6
1983 Actinomma tanyacantha Chen Weaver pl. 5, fig. 3
1990 Actinomma golownini Petrushevskaya Abelmann p. 690, pl. 1, fig. 8
1990 Actinomma golownini Petrushevskaya Lazarus p. 713, pl. 7, figs. 6-8
1992 Actinomma golownini Petrushevskaya Lazarus p. 795

Taxonomic discussion: Petrushevskaya 1975 p.569 pl.2 fig.16; Lazarus 190; Abelmann 1990 (ODP 113 SR) p 691 pl 1 fig; Abelmann 1992 (ODP 120 SR) pl 1 figs 8-9 (synonymy)

Catalog entries: Actinomma golownini, Actinomma tanyacantha

Type images:

type material: A. golownini

Original description: The second shell is about 45µm in diameter, the third about 110-120µm. The fourth shell was absent in all specimens found. Six radial spines rising from the second shell go out from the third shell. The other four spines rise from the third shell and have no connection with the second shell. All 10 spines have acute blades, are wide near the third shell but become very thin at about 60µm so they look like spikes. Pores on the third shell are rather regular, nearly of the same size, and polygonal. The bars between the pores are very narrow. Short by-spines rise from the third shell and are not always seen.
Remarks on original description: The description is based on 23 specimens from Site 278 (Cores 12-15) and on some specimens from the core of "Ob" Station 256.

Description

Published descriptions

Lazarus 1990 - Actinomma golownini virtually always has 14 primary spines arranged at the corners and faces of a cube, and the cortical shell is slightly flattened in most specimens into a subcubical shape. The species is also recognizable by the relatively large cortical pores. Although Petrushevskaya's verbal description is not very accurate (she refers to only 10 primary external 3-blade spines) and the photograph is poor, her species is still identifiable as being equal to Chen's (1974, 1975a) species, and it thus takes priority. There is to my knowledge no other species in the stratigraphic interval in DSDP Site 278 (Leg 29) from which Petrushevskaya based her species description (Cores 12-15) which is similar to A. golownini, and therefore the identification of her species is unambiguous. Actinomma golownini evolves from a form with a spherical (unflattened) cortical shell in the middle Miocene. This ancestral form has more primary spines, smaller cortical pores, and a less regular ar rangement of the primary spines.

Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within Neogene Period (2.59-23.03Ma, top in Piacenzian stage). Data source: Lazarus et al. 2015 - "N age group"
First occurrence (base): within Neogene Period (2.59-23.03Ma, base in Aquitanian stage). Data source: Lazarus et al. 2015 - "N age group"

Plot of occurrence data:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Actinomma golownini, synonyms included - Actinomma golowini; Actinomma golownini; Actinomma tanyacantha; Actinomma glownini;
See also space-time plot :: Samples map :: Parent: Actinomma

References:

Abelmann, A. (1990). Oligocene to Middle Miocene radiolarian stratigraphy of southern high latitudes from Leg 113, Sites 689 and 690, Maud Rise. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 675-708. gs

Abelmann, A. (1992a). Early to Middle Miocene Radiolarian Stratigraphy of the Kerguelen Plateau, Leg 120. Proceedings of the Ocean Drilling Program, Scientific Results. 120: 757-783. gs

Lazarus, D. (1990). Middle Miocene to Recent radiolarians from the Weddell Sea, Antarctica, ODP Leg, 113. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 709-727. gs

Petrushevskaya, M. G. (1975a). Cenozoic radiolarians of the Antarctic, Leg 29, DSDP. Initial Reports of the Deep Sea Drilling Project. 29: 541-675. gs O

Actinomma golownini compiled by the radiolaria@mikrotax project team viewed: 12-10-2024

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