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
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 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
kgbylund at gmail dot com
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.
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.
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.
Gueriau, P., Thoury, M., Escarguel, G.,the
Paris Biota Team,2019a. Glow in the
dark: use of synchrotron mXRF trace elemental mapping and
fossils from the Paris Biota (Bear Lake County, Idaho, USA).Geobios 54, 71-79.
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.
Brayard, A.,the Paris Biota Team,2019.
New thylacocephalans from the Early Triassic Paris Biota (Bear Lake
County, Idaho, USA).Geobios 54, 37–43.
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.
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.
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.
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
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.
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
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
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
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
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
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
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
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
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
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
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
Vol. 4, no. 10. See the Science
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:
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
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
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
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
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
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
Lehi Hintze leading a field trip into the Ibex Area of Utah's
(Site of Jack Watson's Ibex ranch and P.O. in background)
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
Petersen showed me where the Deseret Limestone ammonoids are found.
Duane Bylund, my brother, in the southern House Range
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
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
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
Dr. Hugo Bucher, Dr. Arnaud Brayard, and Jim Jenks
Together we are working on the Early Triassic Ammonoids of Western and
Jim, Jean Guex, Viorel Atudorei
Working on some Spathian Ammonoids in the Confusion Range
Lara Menlove and Holley Jean Carter
Collecting Early Triassic Ammonoids
Helping with the Cretaceous Ammonites and making thin sections
Emmanuelle Vennin, Gilles Escarguel, Daniel
Arnaud Brayard, Emmanuel
Olivier, and James
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.