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Eutrephoceras

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Journal Article

Ontogenetic Change and Intra-specific Variation of Shell Morphology in the Cretaceous Nautiloid (Cephalopoda, Mollusca) Eutrephoceras clementinum (D'Orbigny, 1840) from the Ariyalur Area, Southern India Available to Purchase

Ryoji Wani, Krishnan Ayyasami
Published: 01 May 2009
Journal of Paleontology (2009) 83 (3): 365–378.
DOI: https://doi.org/10.1666/08-119.1
...Ryoji Wani; Krishnan Ayyasami Abstract Morphometric analyses of shell morphology in the Cretaceous nautiloid Eutrephoceras clementinum ( d'Orbigny, 1840 ) (Cephalopoda, Mollusca) from the Ariyalur area, southern India, reveal ontogenetic change from hatching to maturity as well as intra-specific...
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View PDF for article title, Ontogenetic Change and Intra-specific Variation of Shell Morphology in the Cretaceous Nautiloid (Cephalopoda, Mollusca) <span class="search-highlight">Eutrephoceras</span> clementinum (D&#x27;Orbigny, 1840) from the Ariyalur Area, Southern India
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Journal Article

Early ontogeny of Eutrephoceras compared to Recent Nautilus and Mesozoic Ammonites; evidence from shell morphology and light stable isotopes Free

Neil H. Landman, Danny M. Rye, Kevin L. Shelton
Journal: Paleobiology
Published: 01 July 1983
Paleobiology (1983) 9 (3): 269–279.
Add to Citation Manager for Early ontogeny of <span class="search-highlight">Eutrephoceras</span> compared to Recent Nautilus and Mesozoic Ammonites; evidence from shell morphology and light stable isotopes
Journal Article

Notes on comparison of Eutrephoceras eyerdami Palmer, 1961, and Cimonia hesperia Miller and Downs, 1950 Free

Katherine V. W. Palmer
Published: 01 January 1965
Journal of Paleontology (1965) 39 (1): 155.
Add to Citation Manager for Notes on comparison of <span class="search-highlight">Eutrephoceras</span> eyerdami Palmer, 1961, and Cimonia hesperia Miller and Downs, 1950
Journal Article

A new nautiloid, Eutrephoceras eyerdami, new species from the Cowlitz Formation, upper Eocene, of Washington Free

Katherine Van Winkle Palmer
Published: 01 May 1961
Journal of Paleontology (1961) 35 (3): 532–534.
...Katherine Van Winkle Palmer Abstract Eutrephoceras eyerdami Palmer, n. sp., is described from the Cowlitz formation, upper Eocene of Washington. Although fragments of Eutrephoceras have been reported from the locality the present shell is the first to be preserved well enough for specific naming...
Add to Citation Manager for A new nautiloid, <span class="search-highlight">Eutrephoceras</span> eyerdami, new species from the Cowlitz Formation, upper Eocene, of Washington
Journal Article

Tertiary nautiloids (Eutrephoceras and Cimonia) from South Australia Free

B. McGowran
Published: 01 May 1959
Journal of Paleontology (1959) 33 (3): 435–448.
...B. McGowran Abstract Redefines Eutrephoceras geelongensis and E. altifrons from (mainly) lower Miocene beds of the Murray basin, and assigns Nautilus felix, from the upper Eocene of the Adelaide basin, to the genus Cimomia. A description of C. yorkensis n.sp. is also given. GeoRef, Copyright 2004...
Add to Citation Manager for Tertiary nautiloids (<span class="search-highlight">Eutrephoceras</span> and Cimonia) from South Australia
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Fossil cephalopods used in this study. (A) Eutrephoceras dekayi, lower Maastrichtian Pierre Shale, Montana, USA (American Museum of Natural History [AMNH] specimen catalog 108471). (B) Hoploscaphites criptonodosus, upper Maastrichtian Owl Creek Formation, Mississippi, USA (AMNH 138977). (C) Eubaculites latecarinatus, upper Maastrichtian Owl Creek Formation, Mississippi, USA (AMNH 77515). Scale bars = 10 mm.

Fossil cephalopods used in this study. (A) Eutrephoceras dekayi , lower Ma... Open Access

Published: 25 April 2023
Figure 1. Fossil cephalopods used in this study. (A) Eutrephoceras dekayi , lower Maastrichtian Pierre Shale, Montana, USA (American Museum of Natural History [AMNH] specimen catalog 108471). (B) Hoploscaphites criptonodosus , upper Maastrichtian Owl Creek Formation, Mississippi, USA (AMNH
Journal Article

Ammonite extinction and nautilid survival at the end of the Cretaceous Available to Purchase

Neil H. Landman, Stijn Goolaerts, John W.M. Jagt, Elena A. Jagt-Yazykova, Marcin Machalski, Margaret M. Yacobucci
Journal: Geology
Published: 01 August 2014
Geology (2014) 42 (8): 707–710.
DOI: https://doi.org/10.1130/G35776.1
... and survival of nautilids, the two groups of co-occurring, externally shelled cephalopods at the end of the Cretaceous. To investigate the role of geographic distribution in explaining this outcome, we compiled a database of all the occurrences of ammonites and the nautilid genus Eutrephoceras in the last 0.5...
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Septa number vs. δ18O and δ13C from a Eutrephoceras dekayi collected in the Fox Hills formation compared with the pre- to posthatching change in the scaphites measured in this study. Eutrephoceras dekayi data are from sample FH1 (Landman et al. 1983). A and B, Hatching is inferred to have occurred between septa 4 and 5 and is indicated by the dashed vertical gray line. The right axis of both A and B show the δ18O and δ13C values as reported in (Landman et al. 1983). The left axis shows the change in δ18O and δ13C from the average prehatching values (septa 3 and 4). Points scattered around the average Hoploscaphites line indicate the average varix isotope ratio minus the average embryonic isotope ratio for each ammonite. A, From left to right, points are J-125, J-145, J-209, J-215, and J-273. B, From left to right, points are J-145, J-215, and J-273. The average embryonic to varix change is approximately −1‰ for δ18O and +1.9‰ for δ13C. The ammonites in this study clearly show habitat change at hatching that this E. dekayi did not undergo (compare with Figs. 10, 12).

Septa number vs. δ 18 O and δ 13 C from a Eutrephoceras dekayi collected ... Available to Purchase

Published: 03 September 2018
Figure 13. Septa number vs. δ 18 O and δ 13 C from a Eutrephoceras dekayi collected in the Fox Hills formation compared with the pre- to posthatching change in the scaphites measured in this study. Eutrephoceras dekayi data are from sample FH1 (Landman et al. 1983 ). A and B, Hatching
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Geographic distribution of ammonite genera and nautilid Eutrephoceras at the end of the Maastrichtian (see Methodology discussion in text). A: Log10 (geographic area). B: Log10 (maximum distance). Each bin X contains values ranging from X.00 to X.99. The log10 transformation was used so that each bin represents values one order of magnitude larger than the previous bin. The geographic ranges of ammonite genera that survived the Cretaceous-Paleogene event are significantly greater than those of genera that became extinct at or shortly before the event (Mann-Whitney U-test, p = 0.002 for geographic area and p = 0.004 for maximum distance). Ammonites that briefly survived into the Paleocene: a,b—Baculites, c—Hoploscaphites, d—Diplomoceras, e—Pseudophyllites, f,g—Eubaculites, h—Pachydiscus (Pachydiscus); i—the nautilid Eutrephoceras.Scale bar = 1 cm.

Geographic distribution of ammonite genera and nautilid Eutrephoceras at ... Available to Purchase

Published: 01 August 2014
Figure 2. Geographic distribution of ammonite genera and nautilid Eutrephoceras at the end of the Maastrichtian (see Methodology discussion in text). A: Log 10 (geographic area). B: Log 10 (maximum distance). Each bin X contains values ranging from X.00 to X.99. The log 10 transformation
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Anclyoceratina and Eutrephoceras from Union y Progreso. 1–15, Scaphites juv. sp. ex gr. S. hippocrepis (DeKay, 1828): 1, CPC-663; 2, CPC-664; 3, CPC-681; 4, CPC-682; 5, CPC-816; 6, CPC-818; 7, CPC-819; 8, CPC-821; 9, CPC-817; 10, CPC-820; 11, CPC-822; 12, CPC-823; 13, CPC-684; 14, CPC-685; 15, CPC-683; 16, 18–19, Nostoceratidae gen et sp. indet.: 16, CPC-833; 18, CPC-836; 19, CPC-837; 17, 20, 22–24, 26, Pseudoxybeloceras (Parasolenoceras) juv. sp.: 17, CPC-714; 20, CPC-839; 22, CPC-838; 23, CPC-846; 24, CPC-835; 26, CPC-840; 21, 25, Polyptychoceras juv. sp.: 21, CPC-834; 25, CPC-832; 27–29, Eutrephoceras irritilasi n. sp.: 27, CPC-659; 28, holotype CPC-660; 29, CPC-661; all ×1.

Anclyoceratina and Eutrephoceras from Union y Progreso. 1–15 , Scaphite... Available to Purchase

Published: 01 September 2013
Figure 12 Anclyoceratina and Eutrephoceras from Union y Progreso. 1–15 , Scaphites juv. sp. ex gr. S. hippocrepis ( DeKay, 1828 ): 1 , CPC-663; 2 , CPC-664; 3 , CPC-681; 4 , CPC-682; 5 , CPC-816; 6 , CPC-818; 7 , CPC-819; 8 , CPC-821; 9 , CPC-817; 10 , CPC-820; 11 , CPC-822
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Biometry for Eutrephoceras irritilasi n. sp. Asterisks mark estimated o... Available to Purchase

Published: 01 September 2013
Table 9 Biometry for Eutrephoceras irritilasi n. sp. Asterisks mark estimated or uncertain measurements.
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 Figure2—Measured shell morphology of Eutrephoceras clementinum in median (left) and dorsal-ventral (right) sections. D, shell diameter; U, umbilicus diameter; H, whorl height; B, whorl breadth; F, flank position from venter; T, distance between dorsum and venter; and S, siphuncle position from venter

Figure 2 —Measured shell morphology of Eutrephoceras clementinum in medi... Available to Purchase

Published: 01 May 2009
Figure 2 —Measured shell morphology of Eutrephoceras clementinum in median (left) and dorsal-ventral (right) sections. D, shell diameter; U, umbilicus diameter; H, whorl height; B, whorl breadth; F, flank position from venter; T, distance between dorsum and venter; and S, siphuncle position from
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 Figure3—Eutrephoceras clementinum, from locality about 1.5 km east of Anaipadi Village, Ariyalur area, southern India. 1–4, NMNS PM 25,000 from various directions; 5, NMNS PM 25,000 polished along median plane. Note modified umbilical wall of aperture, which bends back toward the center of coiling

Figure 3 — Eutrephoceras clementinum , from locality about 1.5 km east of ... Available to Purchase

Published: 01 May 2009
Figure 3 — Eutrephoceras clementinum , from locality about 1.5 km east of Anaipadi Village, Ariyalur area, southern India. 1–4, NMNS PM 25,000 from various directions; 5, NMNS PM 25,000 polished along median plane. Note modified umbilical wall of aperture, which bends back toward the center
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 Figure13—Early whorl of Eutrephoceras clementinum showing constriction, marked by arrows, NMNS PM 25,001, from locality about 1.5 km east of Anaipadi Village, Ariyalur area, southern India. Shell diameter at constriction is 20 mm. This constriction is interpreted as first aperture at hatching

Figure 13 —Early whorl of Eutrephoceras clementinum showing constriction... Available to Purchase

Published: 01 May 2009
Figure 13 —Early whorl of Eutrephoceras clementinum showing constriction, marked by arrows, NMNS PM 25,001, from locality about 1.5 km east of Anaipadi Village, Ariyalur area, southern India. Shell diameter at constriction is 20 mm. This constriction is interpreted as first aperture at hatching
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 Figure14—Suture lines of Eutrephoceras clementinum, NMNS PM 25,001, from locality about 1.5 km east of Anaipadi Village, Ariyalur area, southern India. 1, at juvenile stage at 70 mm in phragmocone diameter and 51 mm in whorl height; 2, preserved last mature suture at 114 mm in phragmocone diameter and 83 mm in whorl height. Arrows point toward aperture. Abbreviations: V, ventral lobe; USh, lobe in umbilical shoulder; USe, saddle near umbilical seam; D, dorsal lobe

Figure 14 —Suture lines of Eutrephoceras clementinum , NMNS PM 25,001, fr... Available to Purchase

Published: 01 May 2009
Figure 14 —Suture lines of Eutrephoceras clementinum , NMNS PM 25,001, from locality about 1.5 km east of Anaipadi Village, Ariyalur area, southern India. 1, at juvenile stage at 70 mm in phragmocone diameter and 51 mm in whorl height; 2, preserved last mature suture at 114 mm in phragmocone
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Appendix 1.1 — Raw data of shell morphology of Eutrephoceras clementinum ... Available to Purchase

Published: 01 May 2009
Appendix 1.1 — Raw data of shell morphology of Eutrephoceras clementinum from middle Turonian of Ariyalur area, southern India, and allied species.
Journal Article

Ammonoid extinction versus nautiloid survival: Is metabolism responsible? Open Access

Amane Tajika, Neil H. Landman, J. Kirk Cochran, Kozue Nishida, Kotaro Shirai, Toyoho Ishimura, Naoko Murakami-Sugihara, Kei Sato
Journal: Geology
Published: 25 April 2023
Geology (2023) 51 (7): 621–625.
DOI: https://doi.org/10.1130/G51116.1
...Figure 1. Fossil cephalopods used in this study. (A) Eutrephoceras dekayi , lower Maastrichtian Pierre Shale, Montana, USA (American Museum of Natural History [AMNH] specimen catalog 108471). (B) Hoploscaphites criptonodosus , upper Maastrichtian Owl Creek Formation, Mississippi, USA (AMNH...
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Journal Article

An Endemic Cephalopod Assemblage from the Lower Campanian (Late Cretaceous) Parras Shale, Western Coahuila, Mexico Available to Purchase

Christina Ifrim, Wolfgang Stinnesbeck, José Flores Ventura
Published: 01 September 2013
Journal of Paleontology (2013) 87 (5): 881–901.
DOI: https://doi.org/10.1666/12-123
...Figure 12 Anclyoceratina and Eutrephoceras from Union y Progreso. 1–15 , Scaphites juv. sp. ex gr. S. hippocrepis ( DeKay, 1828 ): 1 , CPC-663; 2 , CPC-664; 3 , CPC-681; 4 , CPC-682; 5 , CPC-816; 6 , CPC-818; 7 , CPC-819; 8 , CPC-821; 9 , CPC-817; 10 , CPC-820; 11 , CPC-822...
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View PDF for article title, An Endemic Cephalopod Assemblage from the Lower Campanian (Late Cretaceous) Parras Shale, Western Coahuila, Mexico
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Journal Article

Upper Aptian nautiloids from Colombia Free

J. Wyatt Durham
Published: 01 September 1946
Journal of Paleontology (1946) 20 (5): 428–434.
...J. Wyatt Durham Abstract "Three new species of nautiloids, Cymatoceras colombiana, Eutrephoceras laverdei, and Heminautilus etheringtoni, are described from the upper Aptian [Cretaceous] of Colombia. Heminautilus etheringtoni is discussed at some length and compared with H. stantoni (Scott) and H...
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Journal Article

Zonation of Upper Cretaceous Austin Chalk and Burditt Marl, Williamson County, Texas Available to Purchase

Keith Young, Edward Marks
Journal: AAPG Bulletin
Published: 01 March 1952
AAPG Bulletin (1952) 36 (3): 477–488.
DOI: https://doi.org/10.1306/3D934412-16B1-11D7-8645000102C1865D
... in the Burditt marl of Travis County has been called the Ostrea travisana zone by Stephenson (1937) . The upper biofacies of the Texanites internodosus zone contains the ammonite Texanites internodosus (Renz), T. sp. aff. T. texanus (Roemer), Texanites densinodosus (Renz), Eutrephoceras...
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