pforams@mikrotax - Streptochilus martini

Streptochilus martini

Classification: pf_cenozoic -> Benthic origins -> Streptochilus -> Streptochilus martini
Sister taxa: S. globulosum, S. globigerum, S. latum, S. subglobigerum, S. inglei, S. macdougallae ⟩⟨ S. cetacense, S. mascarenense, S. pristinum, S. rockallkiddense, S. tasmanense ⟩⟨ S. martini, S. sp.


Citation: Streptochilus martini (Pijpers 1933)
Rank: Species
Basionym: Textularia martini

Taxonomic discussion:

Apparently, Pijpers (1933) did not designate a holotype of Textularia martini (= S. martini). SEM images of one of the type specimens (syntypes) of S. martini taken from Pijpers’ collection (Pijpers, 1933, fig. 6) are shown in Plate 19.1, Figs. 1, 2, but unfortunately the specimen has a broken-off final chamber and the aperture cannot be seen clearly. Pijpers (1933) describes the aperture as: “elongate, occasionally slightly curved, at the inner margin of the last formed chamber and perpendicular to that margin”. Huber and others (2006) argued that the Eocene species C. victoriana Beckmann and S. martini should be included within the same species because of the considerable overlap in test elongation and degree of chamber appression. Due to priority, C. victoriana was considered a junior synonym of S. martini (Huber and others, 2006). Eocene Chiloguembelina woodi Samanta was distinguished from S. martini by having more globular chambers and a broader, subcircular, symmetrical aperture (Samanta, 1973). Without detailed information on how these features vary in populations of S. martini, Huber and others (2006) united these taxa. [Smart & Thomas 2018]

Catalog entries: Textularia martini, Chiloguembelina woodi, Guembelina goodwini, Guembelina tenuis, Guembelina venezuelana, Guembelina mauriciana, Chiloguembelina victoriana

Type images:

Distinguishing features:
Parent taxon (Streptochilus): Like Chiloguembelina but with an internal plate connecting successive chambers, a prominent extension of an apertural collar, and a smoother surface texture.
This taxon: Gradually to moderately tapering test without surface ornamentation

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.


Wall type: Microperforate, although low latitude forms may have macroperforations (e.g., Pearson and Wade, 2015), smooth to finely pustulose. [Smart & Thomas 2018]

Morphology: “Test elongate, somewhat compressed, sometimes slightly twisted, gradually to moderately tapering, peripheral margin subrounded; chambers biserial, increasing gradually in size, sutures flush to slightly depressed and oblique in first two to three pairs of chambers, later more strongly depressed and nearly horizontal; aperture a semicircular arch with a thin lip that projects on one side more than the other and an internal toothplate that connects foramina of successive chambers” (Huber and others, 2006:477). [Smart & Thomas 2018]

Size: Syntype length 0.25 mm, width 0.19 mm, thickness 0.11 mm (Plate 19.1, Figs. 1, 2, Pijpers, 1933, fig. 6). [Smart & Thomas 2018]

Character matrix
test outline:Triangularchamber arrangement:Biserialedge view:Equally biconvexaperture:Interiomarginal
sp chamber shape:Globularcoiling axis:N/Aperiphery:N/Aaperture border:Thin flange
umb chbr shape:Globularumbilicus:N/Aperiph margin shape:Moderately roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:N/Awall texture:Smoothshell porosity:Microperforate: <1µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:2.0-2.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution: Cosmopolitan. [Smart & Thomas 2018]

Isotope paleobiology: Late middle Eocene δ18O and δ13C values of S. martini from the northwest Atlantic Ocean (ODP Site 1052) suggest it was a thermocline dweller (Sexton and others, 2006). [Smart & Thomas 2018]

Phylogenetic relations: Huber and others (2006) suggested that S. martini was probably derived from Chiloguembelina crinita during the middle Eocene, but evolution of Streptochilus spp. may have been polyphyletic, from multiple benthic biserial groups. It is likely that the distribution of Streptochilus spp., including S. martini, represents a series of excursions of expatriated tychopelagic individuals into the planktic domain (Darling and others, 2009), explaining the intermittent temporal distribution of Streptochilus in the fossil record. [Smart & Thomas 2018]

Most likely ancestor: Chiloguembelina crinita - at confidence level 3 (out of 5). Data source: Huber et al. 2006.

Biostratigraphic distribution

Geological Range:
Notes: Middle Eocene Zone E10 (Huber and others, 2006) to lower Oligocene Zone O2 (Adriatic Sea). Resig (1993) reported the HO of S. martini at the Eocene/Oligocene boundary at ODP Site 807 (Ontong Java Plateau), although the LO was not recovered. [Smart & Thomas 2018]
Last occurrence (top): within O2 zone (30.28-32.10Ma, top in Rupelian stage). Data source: Smart & Thomas 2018
First occurrence (base): within E10 zone (41.89-43.23Ma, base in Lutetian stage). Data source: Huber et al. 2006

Plot of occurrence data:

Primary source for this page: Smart & Thomas 2018 - Olig Atlas chap.19 p.500; Huber et al. 2006 - Eocene Atlas, chap. 16, p. 477


Beckmann, J. P. (1957). Chiloguembelina Loeblich and Tappan and related foraminifera from the Lower Tertiay of Trinidad, B.W.I. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli & E. Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin. 215: 83-95. gs V O

Cushman, J. A. (1933b). Post-Cretaceous occurrence of Guembelina with a description of a new species. Contributions from the Cushman Laboratory for Foraminiferal Research. 9(3): 64-69. gs V O

Cushman, J. A. (1933c). Some new foraminiferal genera. Contributions from the Cushman Laboratory for Foraminiferal Research. 9(2): 32-38. gs V O

Darling, K. F., Thomas, E., Kasemann, S. A., Seears, H. A., Smart, C. W. & Wade, C. M. (2009). Surviving mass extinction by bridging the benthic/planktic divide. Proceedings of the National Academy of Sciences, USA. 106: 12629-12633. gs

Drooger, C. W. (1953). Miocene and Pleistocene foraminifera from Oranestad, Aruba (Netherlands Antilles). Contributions from the Cushman Foundation for Foraminiferal Research. 4(4): 116-147. gs V O

Hartono, H. M. S. (1969). Globigerina marls and their planktonic foraminifera from the Eocene of Nanggulan, Central Java. Contributions from the Cushman Foundation for Foraminiferal Research. 20(4): 152-159. gs V O

Howe, H. V. (1939). Louisiana Cook Mountain Eocene foraminifera. Bulletin of the Geological Survey of Louisiana. 14: 1-122. gs

Huber, B. T., Olsson, R. K. & Pearson, P. N. (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene microperforate planktonic foraminifera (Jenkinsina, Cassigerinelloita, Chiloguembelina, Streptochilus, Zeauvigerina, Tenuitella, and Cassigerinella) and Problematica (Dipsidripella). In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication. 41(Chap 16): 461-508. gs V O

Nuttall, W. L. F. (1935). Upper Eocene Foraminifera from Venezuela. Journal of Paleontology. 9(2): 121-131. gs

Pearson, P. N. & Wade, B. S. (2015). Systematic taxonomy of exceptionally well-preserved planktonic foraminifera from the Eocene/Oligocene boundary of Tanzania. Cushman Foundation for Foraminiferal Research, Special Publication. 45: 1-85. gs V O

Pijpers, P. J. (1933). Geology and paleontology of Bonaire (D.W.I.). University of Utrecht Geographischeen Geologische Mededeelingen, Phys Geol Reeks. 8: 1-103. gs

Poore, R. Z. & Gosnell, L. B. (1985). Apertural features and surface texture of upper Paleogene biserial planktonic foraminifers: Links between Chiloguembelina and Streptochilus. Journal of Foraminiferal Research. 15: 1-5. gs

Resig, J. M. (1993). Cenozoic stratigraphy and paleoceanography of biserial planktonic foraminifers, Ontong Java Plateau. Proceedings of the Ocean Drilling Program, Scientific Results. 130: 231-244. gs

Samanta, B. K. (1973). Planktonic foraminifera from the Paleocene-Eocene succession in the Rakhi Nala, Sulaiman Range, Pakistan. Bulletin of the British Museum (Natural History) Geology. 22: 421-482. gs

Sexton, P. E., Wilson, P. A. & Pearson, P. N. (2006). Palaeoecology of late middle Eocene planktic foraminifera and evolutionary implications. Marine Micropaleontology. 60: 1-16. gs

Smart, C. W. & Thomas, E. (2018). Taxonomy, biostratigraphy, and phylogeny of Oligocene Streptochilus. In, Wade, B. S., Olsson, R. K., Pearson, P. N., Huber, B. T. & Berggren, W. A. (eds) Atlas of Oligocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication. 46(Chap 19): 495-511. gs V O

Todd, R. (1957). Smaller foraminifera, in Geology of Saipan, Mariana Islands, Pt. 3, Paleontology. U.S. Geological Survey, Professional Paper. 280-H: 265-320. gs V O

Warraich, M. Y. & Ogasawara, K. (2001). Tethyan Paleocene-Eocene planktic foraminifera from the Rakhi Nala and Zinda Pir land sections of the Sulaiman Range, Pakistan. Science Reports of the Institute of Geosciences, University of Tsukuba, Section B Geological Sciences. 22: 1-59. gs


Streptochilus martini compiled by the pforams@mikrotax project team viewed: 21-9-2021

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