Citation: Tenuitella patefacta (Li 1987)taxonomic rank: SpeciesBasionym: Praetenuitella patefactaSynonyms:
Praetenuitellapatefacta Li, 1987:309, pl. 1: figs. 6-10 [upper Eocene, Zone P16-P17, Choctaw County, Alabama, USA].—Poag and Commeau, 1995, pl. 9, figs. 18-20 [Upper Eocene, Zone P15, Exmore Core, Accomomack County, Virginia].—Li and others, 1995:132-133, pl. 4: figs. 4-5 [upper Eocene, ODP Hole 749B, Kerguelen Plateau, southern Indian Ocean].
Praetenuitellainsolita (Jenkins).—Li and others, 1995, pl. 4, figs. 6-8 [upper Eocene, ODP Hole 749B, Kerguelen Plateau, southern Indian Ocean]. [Not Jenkins, 1966.]
Globorotalia gemma (Jenkins). Poore and Bybell, 1988:16, pl. 3: figs. 1-6 [upper Eocene Turborotaliacunialensis Zone, ACGS #4 borehole, Cape May, New Jersey Coastal Plain]. [Not Jenkins, 1966.]
Tenuitella gemma (Jenkins).—Huber, 1991:441, pl. 7: figs. 7-8 [lower Oligocene, ODP Site 744, Kerguelen Plateau, southern Indian Ocean]. [Not Jenkins, 1966.]
Taxonomic discussion: Comparison of the test outline, umbilical morphology, and height of the aperture in the T. patefacta holotype (re-illustrated on Pl. 16.7, Figs. 1-2) with those features on the holotype of T. gemma (Pl.16.7, Figs. 16-18) and illustrations of T. insolita (Pl.16.5) reveals why Li (1987) considered patefacta to be the intermediate link between insolita and gemma. Specimens designated as Praetenuitellapatefacta by Poag and Commeau (1995) (re-illustrated on Pl. 16.7, Figs. 3-5) have a more circular aperture and a more closed umbilicus than Li’s primary type specimens but still fall within Li’s species concept. An early Oligocene specimen designated by Huber (1991) as T. gemma (re-illustrated on Pl. 16.7: Figs. 9-10) is too deeply umbilicate for that species and is reassigned to T. patefacta despite having a narrower and deeper umbilicus than found in Li’s (1987) type specimen. This latter specimen is nearly identical to a specimen assigned to T. patefacta from the upper Eocene specimen from the New Jersey Coastal Plain (Pl.16.7, Figs. 6-8). A specimen previously assigned to T. praegemma forma typica by Poag and Commeau (1995) (see Pl. 16.7, Figs. 13-14) is here considered to be T. patefacta because of its more highly arched aperture, but the more pendulous and axially broadening of the chambers and more closed umbilicus are suggestive of T. praegemma. A specimen designated as Globorotalia gemma by Poore and Bybell (1988; re-illustrated on Pl. 16.7, Figs. 11-12) is reassigned to T. patefacta because of its relatively lobate equatorial outline and more open umbilicus. [Huber et al. 2006]
Distinguishing features: Parent taxon (Tenuitella): Minute to small, low trochospiral test, with globular chambers. Monolamellar, microperforate wall with a smooth or finely pustulate surface. This taxon: Like T.insolita but with a low rather than highly arched, extraumbilical aperture
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.
Description
Morphology: Test small, lobate circular in equatorial outline, equatorial periphery rounded; chambers globular, coiled in a very low trochospire, increasing gradually in size, 5-6 in the final whorl, nearly symmetrical in edge view; sutures depressed, curved on the spiral side, radial on umbilical side; umbilicus small; aperture a low extraumbilical-umbilical arch bordered by a narrow, equidimensional lip. [Huber et al. 2006] Wall type: Microperforate, surface smooth to finely pustulose, pustules irregularly scattered on umbilical and spiral sides of test. [Huber et al. 2006] Size: Holotype maximum diameter: 0.16 mm. [Huber et al. 2006]
Character matrix
test outline:
Lobate
chamber arrangement:
Trochospiral
edge view:
Equally biconvex
aperture:
Umbilical-extraumbilical
sp chamber shape:
Globular
coiling axis:
Very low
periphery:
N/A
aperture border:
Thin lip
umb chbr shape:
Globular
umbilicus:
Wide
periph margin shape:
Moderately rounded
accessory apertures:
None
spiral sutures:
Strongly depressed
umb depth:
Shallow
wall texture:
Finely pustulose
shell porosity:
Microperforate: <1µm
umbilical or test sutures:
Strongly depressed
final-whorl chambers:
5-6
N.B. These characters are used for advanced search. N/A - not applicable
Biogeography and Palaeobiology
Geographic distributionFew records of this species have been published. Identified in upper Eocene sediments from the Atlantic coastal plain and the southern Indian Ocean. [Huber et al. 2006] Isotope paleobiologyNo data available. [Huber et al. 2006] Phylogenetic relationsDescended from T. insolita during the late Eocene; ancestral to T. gemma, which first appeared during the latest Eocene. [Huber et al. 2006]
Most likely ancestor:Tenuitella insolita - at confidence level 4 (out of 5). Data source: Huber et al. 2006 f16.2.
Biostratigraphic distribution
Geological Range: Notes: Upper Eocene; Zone E15 to E16. [Huber et al. 2006] Last occurrence (top): within E16 zone (33.90-34.68Ma, top in Priabonian stage). Data source: Huber et al. 2006 f16.2 First occurrence (base): within E15 zone (34.68-35.89Ma, base in Priabonian stage). Data source: Huber et al. 2006 f16.2
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: Tenuitella patefacta, synonyms included - Tenuitella patefacta;
Primary source for this page: Huber et al. 2006 - Eocene Atlas, chap. 16, p. 490
References:
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. gsO
Jenkins, D. G. (1966b). Planktonic foraminiferal zones and new taxa from the Danian to lower Miocene of New Zealand. New Zealand Journal of Geology and Geophysics. 8 [1965](6): 1088-1126. gs
Li, Q. (1987). Origin, phylogenetic development and systematic taxonomy of the Tenuitella plexus (Globigerinitidae, Globigerininina). Journal of Foraminiferal Research. 17: 298-320. gs
Li, Q., McGowran, B. & Boersma, A. (1995). Early Palaeocene Parvularugoglobigerina and late Eocene Praetenuitella: does evolutionary convergence imply similar habitat? Journal of Micropalaeontology. 14: 119-134. gs
Poag, C. W. & Commeau, J. A. (1995). Paleocene to middle Miocene planktic foraminifera of the southwestern Salisbury Embayment, Virginia and Maryland: Biostratigraphy, allostratigraphy, and sequence stratigraphy. Journal of Foraminiferal Research. 25: 134-155. gs
Poore, R. Z. & Bybell, L. M. (1988). Eocene to Miocene biostratigraphy of New Jersey Core ACGS #4: Implications for regional stratigraphy. U.S. Geological Survey Bulletin. 1829: 1-41. gs
Tenuitella patefacta compiled by the pforams@mikrotax project teamviewed: 9-10-2024
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holotype: P. patefacta
holotype: P. patefacta
paratype: P. patefacta
paratype: P. patefacta
