radiolaria - rads_cenozoic - Larcospira quadrangula

Citation: Larcospira quadrangula Haeckel 1887

Basionym: Larcospira quadrangula

Synonyms:
1887 Larcospira quadrangula - Haeckel p. 696; pl. 49, fig. 3
1966 Larcospira quadrangula - Benson p. 266-268; pl. 18, figs. 7-8
1970 Larcospira quadrangula - Nigrini p. 169; pl.2, fig. 9
1971 Larcospira quadrangula - Casey pl. 23.3, fig. 8
1977 Larcospira quadrangula - Kling p. 217; pl. 2, fig. 18
1977 Larcospira quadrangula - Molina-Cruz p. 335; pl. 3, fig. 3
1979 Larcospira quadrangula - Nigrini and Moore p. S133-S134; pl. 17, fig. 2
1983 Larcospira quadrangula - Benson p. 505
1995 Larcospira quadrangula - van de Paverd p.188-190; pl. 55, figs. 1-2, 4-5
1998 Larcospira quadrangula - Boltovskoy fig. 15.86

Taxonomic discussion: Haeckel 1887

Original description: Cortical shell with thorny surface, three times as long as the lentelliptical medullary shell. Perimeter of the lateral plane nearly quadrangular, with four rounded corners (on the poles of two crossed diagonal axes), one and a third times as long as broad, with one sagittal constriction at the poles of the principal axis. One lateral wing of the transverse girdle turns around the other in one and a half to two simple spiral turns.
Remarks on original description: Haeckel listed Larcospira quadrangula under the subgeneric name Larcospirema, but did not include the subgeneric name in the species name.[comment from RadWorld database]

Description

Benson 1966 - Larcospira quadrangula

Fully developed tests subquadrangular in outline but with a sagittal constriction. Structure consisting of a double spiral representing a turning of two diagonally opposite wings of the second transverse girdle around the principal axis of the test; the other two wings of this girdle are absent. The wings are attached proximally to two oppositely placed, cylindrical, polar (coaxial with principal shell axis) beams, each of which arises from the innermost ellipsoidal shell from which is developed the inner trizonal shell surrounding it; the two spiral wings of the second transverse girdle arise from the trizonal shell. Each of the two wings are elongated parallel to the principal axis and form half-cylindroidal chambers whose openings face in opposite directions. Wings (chambers) supported by several thin, cylindrical, radial beams which arise from the surface of the inner trizonal shell. Lattice of test with subequal to unequal, subpolygonal pores, subregularly arranged, separated by thin intervening bars. Surface of test with scattered thorns or short, thin, conical spines.

Measurements: based on 13 specimens from stations 27, 34, 60, 81, 91, 106, and 184: length of P1 axis (innermost shell) 31-36 m, of P2 axis (inner trizonal shell) 68-82 µm, of P3 axis (sagittal constriction of fully developed forms) 135-209 µm, of T1 axis 18-27 µm, of T2 axis 43-64 µm, of T3 axis (maximum breadth of fully developed tests) 125-246 µm.

Remarks: Haekel's illustration of this species does not show any differences from the Gulf specimens. However, he placed L. quadrangula in his subgenus Larcospirema Haeckel (1887, p. 696) which he defines as comprising tests with only one wing of the transverse girdle turning around the principal axis. His illustration, however, shows two wings turning around this axis.

Distribution: This species is rare in the Gulf, occurring only at stations 27, 34, 46, 56, 60, 81, 91, 92, 93, 106, 115, and 184.Its near absence in the northern half of the Gulf indicates that it is an oceanic species. Haeckel reported this species from the central Pacific atChallengerstation 265.It has not been reported from high latitudes; therefore, it is probably restricted to tropical regions. \ From: Benson, 1966, p. 266-268; pl. 18, figs. 7-8:Larcospira quadrangula HaeckelLarcospira quadrangula Haeckel, 1887, Challenger Rept., Zool., vol. 18, p. 696, Pl. 49, fig. 3.

Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant. Data source: Lazarus et al. 2015 - "R age group"
First occurrence (base): within Quaternary Period (0-2.59Ma, base in Gelasian stage). Data source: Lazarus et al. 2015 - "R age group"

References:

Benson, R. N. (1966). Recent Radiolaria from the Gulf of California. Thesis, Minnesota University. 1-577. gs

Benson, R. N. (1983). Quaternary radiolarians from the Mouth of the Gulf of California, Deep Sea Drilling Project Leg 65. Initial Reports of the Deep Sea Drilling Project. 65: 491-523. gs

Boltovskoy, D. (1998). Classification and distribution of south Atlantic recent polycystine Radiolaria. Palaeontologia Electronica. -. gs

Casey, R. E. (1971c). Radiolarians as indicators of past and present water-masses. In, Funnel, B. M. & Riedel, W. R (eds) The Micropaleontology of Oceans. Cambridge University Press, Cambridge, UK 331-341. gs

Haeckel, E (1887). Report on the Radiolaria collected by H.M.S. Challenger during the years 1873-1876. Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873-1876. 18: 1-1803. gs O

Kling, S. A. (1977). Local and regional imprints on radiolarian assemblages from California coastal basin sediments. Marine Micropaleontology. 2(2): 207-221. gs

Molina-Cruz, A. (1977). Radiolarian assemblages and their relationship to the oceanography of the subtropical southeastern Pacific. Marine Micropaleontology. 2(4): 315-352. gs

Nigrini, C. A. & Moore, T. C. Jr. (1979). A guide to modern Radiolaria. Cushman Foundation for Foraminiferal Research, Special Publication. 16: 1-260. gs O

Nigrini, C. A. (1970). Radiolarian assemblages in the North Pacific and their application to a study of Quarternary sediments in Core V 20-130. Geological Society of America, Memoir. 126: 139-175. gs

van de Paverd, P. J. (1995). Recent Polycystine Radiolaria from the Snellius-II Expedition. Thesis, Free University Amsterdam. 1-351. gs

Larcospira quadrangula

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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