About this site and the author

This site is meant to be a reference to help provide information on the identity, biostratigraphy and location of fossil cephalopods found in the state of Utah. All fossils shown on this site were collected, or photographed in the field, by the author. They were all found on public land, administered by either the Bureau of Land Management (BLM) or the United States Forest Service (USFS). Or land formerly administered by the BLM that is now property of the State of Utah.

Fossils shown on this site are NOT for sale or trade. I am not against the selling and trading of fossils, it's just that I choose not to participate, and abide the law. For rules pertaining to fossil collecting in Utah, see collecting rules at this UGS site.

There is no copyright on any of the pages or photographs, except for logos, photographs, or names, owned by other sites. It would be nice however, if you use some of my photographs, to mention where they come from, and link back to this site.

This site is owned and maintained by Kevin Bylund, shown below in the desert of western Utah collecting fossil cephalopods. I am an amateur paleontologist with an interest in cephalopods and cephalopod biostratigraphy, and sometimes an avocational paleontologist helping local universities and surveys in some of their dinosaur quarries. A member of the Paleontological Society, the Palaeontological Association, and the Utah Friends of Paleontology.

Comments, Questions, Suggestions
Email
kgbylund at gmail dot com

Ammonoidea (my blog site)

Papers:

Bylund, K.G., and Stephen, D.A., in press, Late Early Coniacian (Cretaceous) Ammonites from central Utah, In: Slattery, J.S., Larson, N.L., Bingle-Davis, M., and Bingle-Davis, M. (eds.), Insights into the Cretaceous: Building on the Legacy of William A. Cobban (1916-2015), American Association of Petroleum Geologists and Wyoming Geological Association Special Volume.

Kirkland, J.I., King, M.R., and Bylund, K.G., 2025, Revisiting the Cretaceous Mancos Group in Utah - problems, previous methods, and new perspectives on a world-class Cretaceous marine section: Geology of the Intermountain West, v. 12, p. 75-154.

James F Jenks, Takumi Maekawa, Yasunari Shigeta, David Ware, Arnaud Brayard, Kevin G Bylund, Daniel A Stephen, Noreen Kittrick, 2025, Early Dienerian ammonoids and nautiloids and a new late Griesbachian ammonoid site from the Dinwoody Formation (Thaynes Group) at Crittenden Springs, Elko County, Nevada. New Mexico Museum of Natural History and Science Bulletin 97, p.1-29.

Smith C.P.A, Aubier P, Charbonnier S, Laville T, Olivier N, Escarguel G, Jenks JF, Bylund K.G., Fara E, Brayard A., 2023, Closing a major gap in mantis shrimp evolution - first fossils of Stomatopoda from the Triassic, Bulletin of Geosciences, volume 98, issue 1; pages: 95 - 110

Smith, C.P.A., Charbonnier, S., Jenks, J.F., Bylund, K.G., Escarguel, G., Olivier, N., Fara, E., and Brayard, A., 2022, The Paris Biota decapod (Arthropoda) fauna and the diversity of Triassic decapods, Journal of Paleontology DOI: https://doi.org/10.1017/jpa.2022.34

Smith, C.P.A., Laville, T., Fara, E., Escarguel, G., Olivier, N., Vennin, E., Goudemand, N., Bylund, K.G., Jenks, J.F., Stephen, D.A., Hautmann, M., Charbonnier, S., Krumenacker, L.J., & Brayard, A., 2021, Exceptional fossil assemblages confirm the existence of complex Early Triassic ecosystems during the early Spathian. Sci Rep 11, 19657 (2021). https://doi.org/10.1038/s41598-021-99056-8

Brayard, A., Jenks, J.F., Bylund, K.G., Olivier, N., Vennin, E., Stephen, D.A., Escarguel, G., and Fara, E., 2021, Latest Smithian (Early Triassic) ammonoid assemblages in Utah (western USA basin) and their implications for regional biostratigraphy, biogeography and placement of the Smithian/Spathian boundary. Geobios.

Jenks, J.F., Maekawa, T., Ware, D., Shigeta, Y., Brayard, A., and Bylund, K.G., 2021, Late Griesbachian (Early Triassic) Ammonoids and Nautiloids from the Dinwoody Formation at Crittendon Springs, Elko County, Nevada. New Mexico Museum of Natural History & Science, Bulletin 86.

Brayard, A., Olivier, N., Vennin, E., Jenks, J.F., Bylund, K.G., Stephen, D.A., McShinsky, D., Goudemand, N., Fara, E., Escarguel, G., 2020, New middle and late Smithian ammonoid faunas from the Utah/Arizona border: New evidence for calibrating Early Triassic transgressive-regressive trends and paleobiogeographical signals in the western USA basin, Global and Planetary Change, 192, https://doi.org/10.1016/j.gloplacha.2020.103251.

Botting, J.P., Brayard, A., the Paris Biota Team, 2019. A late-surviving Triassic protomonaxonid sponge from the Paris Biota (Bear Lake County, Idaho, USA). Geobios 54, 5-11.

Brayard, A., Gueriau, P., Thoury, M., Escarguel, G., the Paris Biota Team, 2019a. Glow in the dark: use of synchrotron mXRF trace elemental mapping and multispectral

macro-imaging on fossils from the Paris Biota (Bear Lake County, Idaho, USA). Geobios 54, 71-79.

Brayard, A., Jenks, J.F., Bylund, K.G., the Paris Biota Team, 2019b. Ammonoids and nautiloids from the earliest Spathian Paris Biota and other early Spathian localities in southeastern Idaho, USA. Geobios 54, 13-36.

Charbonnier, S., Brayard, A., the Paris Biota Team, 2019. New thylacocephalans from the Early Triassic Paris Biota (Bear Lake County, Idaho, USA). Geobios 54, 37–43.

Iniesto, M., Thomazo, C., Fara, E., the Paris Biota Team, 2019. Deciphering the exceptional preservation of the Early Triassic Paris Biota (Bear Lake County, Idaho, USA). Geobios 54, 81-93.

Romano, C., Argyriou, T., Krumenacker, L.J., the Paris Biota Team, 2019. Chondrichthyan teeth from the Early Triassic Paris Biota (Bear Lake County, Idaho, USA). Geobios 54, 63-70.

Saucede, T., Vennin, E., Fara, E., Olivier, N., the Paris Biota Team, 2019. A new holocrinid (Articulata) from the Paris Biota (Bear Lake County, Idaho, USA) highlights the high diversity of Early Triassic crinoids. Geobios 54, 45-53.

Thuy, B., Escarguel, G., the Paris Biota Team, 2019. A new brittle star (Ophiuroidea: Ophiodermatina) from the Early Triassic Paris Biota (Bear Lake County, Idaho, USA). Geobios 54, 55-61.

C. Thomazo, A. Brayard, S. Elmeknassi, E. Vennin, N. Olivier, G. Caravaca, G. Escarguel, E. Fara, K.G. Bylund, J.F. Jenks, D.A. Stephen, B. Killingsworth, P. Sansjofre, P. Cartigny, 2018, Multiple sulfur isotope signals associated with the late Smithian event and the Smithian/Spathian boundary, Earth-Science Reviews (CP)

Larisa A Doguzhaeva, Arnaud Brayard, Nicolas Goudemand, Laurel J Krumenacker, James F Jenks, Kevin G Bylund, Emmanuel Fara, Nicolas Olivier, Emmanuelle Vennin, Gilles Escarguel, 2018, An Early Triassic gladius associated with soft tissue remains from Idaho, USA—a squid-like coleoid cephalopod at the onset of Mesozoic Era, Acta Palaeontologica Polonica, 63:2 p341-355

Romain Jattiot, Arnaud Brayard, Hugo Bucher, Emmanuelle Vennin, Gwenael Caravaca, James F Jenks, Kevin G Bylund, Gilles Escarguel, 2018, Palaeobiogeographical distribution of Smithian (Early Triassic) ammonoid faunas within the western USA basin and its controlling parameters, Palaeontology

Nicolas Olivier, Emmanuel Fara, Emmanuelle Vennin, Kevin G Bylund, James F Jenks, Gilles Escarguel, Daniel A Stephen, Nicolas Goudemand, Dawn Snyder, Christophe Thomazo, Arnaud Brayard, 2018, Late Smithian microbial deposits and their lateral marine fossiliferous limestones (Early Triassic, Hurricane Cliffs, Utah, USA) Facies 64:2 13 pg.

Grosjean, Anne-Sabine; Vennin, Emmanuelle; Olivier, Nicolas; Caravaca, Gwénaël; Thomazo, Christophe; Fara, Emmanuel; Escarguel, Gilles; Bylund, Kevin G.; Jenks, James F.; Stephen, Daniel A.; Brayard, Arnaud; 2018, Early Triassic environmental dynamics and microbial development during the Smithian–Spathian transition (Lower Weber Canyon, Utah, USA) Sedimentary Geology, 363, p 136-151

Jattiot, R., Bucher, H., Brayard, A., Brosse,M., Jenks, J.F., Bylund, K.G., 2017. Smithian ammonoid faunas from northeastern Nevada: implications for Early Triassic biostratigraphy and correlation within the western USA basin. PalaeontographicaA (Paleozoology, Stratigraphy) 309, 1–89.

Romano, C., Jenks, J., Jattiot, R., Scheyer, T., Bylund, K. G., & Bucher, H. 2017. Marine Early Triassic Actinopterygii from Elko County (Nevada, USA): Implications for the Smithian equatorial vertebrate eclipse. Journal of Paleontology

Gwénaël Caravaca, Christophe Thomazo, Emmanuelle Vennin, Nicolas Olivier, Théophile Cocquerez, Gilles Escarguel, Emmanuel Fara, James F. Jenks, Kevin G. Bylund, Daniel A. Stephen, Arnaud Brayard, 2017, Early Triassic fluctuations of the global carbon cycle: New evidence from paired carbon isotopes in the western USA basin, Global and Planetary Change

Loïc Villier, Arnaud Brayard, Kevin G. Bylund, James F. Jenks, Gilles Escarguel, Nicolas Olivier, Daniel A. Stephen, Emmanuelle Vennin, and Emmanuel Fara, 2017, Superstesaster promissor gen. et sp. nov., a new starfish (Echinodermata, Asteroidea) from the Early Triassic of Utah, USA, filling a major gap in the phylogeny of asteroids, Journal Of Systematic Palaeontology

Gwénaël Caravaca, Arnaud Brayard, Emmanuelle Vennin, Michel Guiraud, Laetitia Le Pourhiet, Anne-Sabine Grosjean, Christophe Thomazo, Nicolas Olivier, Emmanuel Fara, Gilles Escarguel, Kevin G Bylund, James F Jenks, Daniel A Stephen, 2017, Controlling factors for differential subsidence in the Sonoma Foreland Basin (Early Triassic, western USA), Geological Magazine

A. Brayard, L. J. Krumenacker, J. P. Botting, J. F. Jenks, K. G. Bylund, E. Fara, E. Vennin, N. Olivier, N. Goudemand, T. Saucède, S. Charbonnier, C. Romano, L. Doguzhaeva, B. Thuy, M. Hautmann, D. A. Stephen, C. Thomazo, G. Escarguel, 2017, Unexpected Early Triassic marine ecosystem and the rise of the Modern evolutionary fauna. Sci. Adv. 3, e1602159

Thomazo, C; E. Vennin, A. Brayard, I. Bour, O. Mathieu, S. Elmeknassi, N. Olivier, G. Escarguel, K. G. Bylund, J. Jenks, D. A. Stephen, E. Fara, 2016, A diagenetic control on the Early Triassic Smithian–Spathian carbon isotopic excursions recorded in the marine settings of the Thaynes Group (Utah, USA) , Geobiology

Brayard, Arnaud, Meier, Maximiliano, Escarguel, Gilles, Fara, Emmanuel, Nützel, Alexander, Olivier, Nicolas, Bylund, Kevin G., Jenks, James F, Stephen, Daniel A, Hautmann, Michael, 2015, Early Triassic Gulliver gastropods: Spatio-temporal distribution and significance for biotic recovery after the end-Permian mass extinction; Earth-Science Reviews 146:31-64

Vennin, Emmanuelle, Olivier, Nicolas, Brayard, Arnaud, Bour, Ivan, Thomazo, Christophe, Escarguel, Gilles, Fara, Emmanuel, Bylund, Kevin G, Jenks, James F, Stephen, Daniel, 2015, Microbial deposits in the aftermath of the end-Permian mass extinction: A diverging case from the Mineral Mountains (Utah, USA); Sedimentology 62:753-792

Olivier, Nicolas, Brayard, Arnaud, Vennin, Emmanuelle, Escarguel, Gilles, Fara, Emmanuel, Bylund, Kevin G, Jenks, James F; Caravaca, Gwénaël, Stephen, Daniel A, 2015, Evolution of depositional settings in the Torrey area during the Smithian (Early Triassic, Utah, USA) and their significance for the biotic recovery; Geological Journal

Olivier, Nicolas, Brayard, Arnaud, Fara, Emmanuel, Bylund, Kevin G, Jenks, James F, Vennin, Emmanuelle, Stephen, Daniel A, Escarguel, Gilles, 2014, Smithian shoreline migrations and depositional settings in Timpoweap Canyon (Early Triassic, Utah, USA); Geological Magazine 151:938-955

Hofmann, Richard; Hautmann, Michael; Brayard, Arnaud; Nützel, Alexander; Bylund, Kevin G; Jenks, James F; Vennin, Emmanuelle; Olivier, Nicolas; Bucher, Hugo; 2014, Recovery of benthic marine communities from the end-Permian mass extinction at the low latitudes of eastern Panthalassa; Palaeontology 57:547-589

Brayard, A., Bylund, K. G., Jenks, J., Stephen, D. A., Olivier, N., Escarguel, G., Fara, E. & Vennin, E., 2013. Smithian ammonoid faunas from Utah: implications for Early Triassic biostratigraphy, correlations and basinal paleogeography. Swiss Journal of Paleontology 132:141-219.

Daniel A. Stephen, Kevin G. Bylund, Patricia Garcia, R. Dawn McShinsky, Holley Jean Carter, 2012, Taphonomy of dense concentrations of juvenile ammonoids in the Upper Cretaceous Mancos Shale, east-central Utah, USA. Geobios 45(1):121-128.

Arnaud Brayard, Emmanuelle Vennin, Nicolas Olivier, Kevin G. Bylund, Jim Jenks, Daniel A. Stephen, Hugo Bucher, Richard Hofmann, Nicolas Goudemand & Gilles Escarguel, 2011, Transient metazoan reefs in the aftermath of the end-Permian mass extinction, Nature Geoscience , Vol. 4, no. 10. See the Science Daily story

Arnaud Brayard, Alexander Nützel, Andrzej Kaim, Gilles Escarguel, Michael Hautmann, Daniel A. Stephen, Kevin G. Bylund, Jim Jenks, and Hugo Bucher, 2011, Gastropod evidence against the Early Triassic Lilliput effect: REPLY Geology, v. 39, p. e233

Arnaud Brayard, Alexander Nützel, Daniel A. Stephen, Kevin G. Bylund, Jim Jenks, and Hugo Bucher, 2010, Gastropod evidence against the Early Triassic Lilliput effect, Geology , v. 38, no. 2, p. 147-150.

Daniel A. Stephen, Kevin G. Bylund, Paul J. Bybee and Wesley J. Ream, 2010, Ammonoid Beds in the Lower Triassic Thaynes Formation of western Utah, USA, in: Cephalopods – Present and Past, edited by K. Tanabe, Y. Shigeta and T. Sasaki & H. Hirano. Tokai University Press, Tokyo, p. 243-252

Pisera, Andrzej, Rigby, J. Keith and Bylund, Kevin G., 1996, Lower Triassic Hexactinellid Sponges from the Confusion Range, Western Utah: Brigham Young University Geology Studies, vol. 27, pt 2 Download a copy Here

Pictures of ammonoids I have collected have been published in:

Hintze, L. F., and Davis, F. D., 2003, Geology of Millard County, Utah: Utah Geological Survey Bulletin 133

Hintze, L. F., 2005, Utah's Spectacular Geology: How It Came to Be: BYU Print Services

Colin Dunlop and Nancy King, , 2008, Cephalopods: Octopuses and Cuttlefish for the Home Aquarium, TFH Publications

Hintze, L. F., and Kowallis, B. J., 2009, Geologic History of Utah: BYU Geology Studies, Special Publication 9

Abstracts:

D.A. STEPHEN, K.G. BYLUND, H.J. CARTER, P. GARCIA, 2010, Taphonomy of dense concentrations of juvenile ammonoids in the Mancos Shale, east-central Utah, USA, 8th International Symposium, Cephalopods – Present and Past (Dijon – France 2010), Oral presentation, Abstract volume.

K.G. BYLUND & D.A. STEPHEN, 2010, Coniacian (Late Cretaceous) ammonoid fauna of eastern Utah, USA, 8th International Symposium, Cephalopods – Present and Past (Dijon – France 2010) Poster Abstract volume.

K.G. BYLUND, D.A. STEPHEN, A. BRAYARD, H. BUCHER, J. JENKS, R.D. McSHINSKY, 2010, Early Triassic ammonoids from the Pahvant Range, Utah, USA, 8th International Symposium, Cephalopods – Present and Past (Dijon – France 2010) Poster Abstract volume.

D.A. STEPHEN & K.G. BYLUND, 2010, Late Cretaceous nautiloids from eastern Utah, USA, 8th International Symposium, Cephalopods – Present and Past (Dijon – France 2010) Poster Abstract volume.

Daniel A. Stephen, Kevin G. Bylund, Arnaud Brayard, and Hugo Bucher, 2009, LOWER TRIASSIC AMMONOID BIOSTRATIGRAPHY OF CENTRAL AND WESTERN UTAH, 9th North American Paleontological Convention, June 21-26, 2009, Cincinatti, Ohio.

STEPHEN, Daniel A., MENLOVE, Lara, GOUDEMAND, Nicolas, BYLUND, Kevin G., BRAYARD, Arnaud, McSHINSKY, RaNae Dawn, BUCHER, Hugo, and JENKS, Jim, 2009: EARLY TRIASSIC CONODONTS IN THE PAHVANT RANGE OF CENTRAL UTAH: Abstracts with Programs, Vol. 41, No. 6 Geological Society of America, Rocky Mountain Section (61st Annual) Meeting (11–13 May 2009)

BYLUND, Kevin G., STEPHEN, Daniel A., BRAYARD, Arnaud, BUCHER, Hugo, JENKS, Jim, and McSHINSKY, RaNae Dawn, 2009: AMMONOIDS OF THE LOWER TRIASSIC THAYNES GROUP IN THE PAHVANT RANGE, UTAH: Geological Society of America Abstracts with Programs, Vol. 41, No. 6, Rocky Mountain Section (61st Annual) Meeting (11–13 May 2009)

Dan Stephen, Kevin Bylund, Paul Bybee and Wes Ream, 2008, LOWER TRIASSIC AMMONOID BEDS IN THE CONFUSION RANGE OF WESTERN UTAH: Geological Society of America Abstracts with Programs, Vol. 40, No. 1, Cordilleran Section (104th Annual) and Rocky Mountain Section (60th Annual) Joint Meeting (19–21 March 2008), pg. 59
(be sure to download a copy (4.8M pdf) of the presentation I gave "presentation handout"

Dan Stephen, Kevin Bylund, Paul Bybee and Wes Ream, 2007, AMMONOID MASS MORTALITY BEDS IN THE LOWER TRIASSIC THAYNES FORMATION OF WESTERN UTAH, USA: Seventh International Symposium Cephalopods – Present and Past, 2007, Sapporo, Japan. Abstracts of Oral Presentations, pg. 33

Acknowledgements:

Dr. Lehi Hintze leading a field trip into the Ibex Area of Utah's West Desert
(Site of Jack Watson's Ibex ranch and P.O. in background)
2004

Dr. Hintze has helped with many fossil localities in Western Utah, particularly the Ordovician sections

Dr. Morris Petersen and Jared Morrow
at a site for Early Mississippian Ammonoids

2004

Dr. Petersen showed me where the Deseret Limestone ammonoids are found.

Duane Bylund, my brother, in the southern House Range
2004

Many of the cephalopods pictured on this site were found by him

Dr. Dan Stephen at an outcrop of the Triassic Thaynes Formation
The Anasibirites Beds
2007

Dan has been instrumental in getting the study of the Anasibirites Beds on paper.

Dr's Dieter Korn and Alan Titus
at Granite Mountain collecting Mississippian ammonoids
2007

I learned a great deal from these two during the 4 days spent collecting in western Utah and eastern Nevada, and Alan has helped considerably with the taxonomy and biostratigraphy of Mississippian ammonoids.

Dawn McShinsky has helped measure sections and collect ammonoids
2008

Dr. Hugo Bucher, Dr. Arnaud Brayard, and Jim Jenks
Together we are working on the Early Triassic Ammonoids of Western and Central Utah.
2008

Jim, Jean Guex, Viorel Atudorei
Working on some Spathian Ammonoids in the Confusion Range
2009

Lara Menlove and Holley Jean Carter
Collecting Early Triassic Ammonoids
2009

Patti Garcia
Helping with the Cretaceous Ammonites and making thin sections
2010

Emmanuelle Vennin, Gilles Escarguel, Daniel A. Stephen, Arnaud Brayard, Emmanuel Fara, Nicolas Olivier, and James F. Jenks

The Utah Early Triassic Crew
2013

This site was started in December 1999, and first published on the world wide web as Old Calamari with Xoom.com in February 2000. Later Xoom.com changed to NBCI.com, after a few years they stopped offering free web space so I moved the site to Topcities.com, only to have them shut down. On October 2, 2003, I registered the domain ammonoid.com, where the site is now.

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