Prince Creek Formation

The Prince Creek Formation is a geological formation in Alaska with strata dating to the Late Campanian stage of the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.^[2]

Prince Creek Formation
Stratigraphic range: Latest Campanian ~73 ma
General location of the Prince Creek Formation, in red
Type	Geological formation
Unit of	Colville Group
Sub-units	Kikak-Tegoseak Quarry, Kogosukruk Tongue, Ocean Point, Coleville River Bluff
Underlies	Sagavanirktok Formation
Overlies	Schrader Bluff Formation
Lithology
Primary	Sandstone, mudstone[1]
Other	siltstone, carbonaceous shale, ash-fall[1]
Location
Coordinates	70.0°N 151.5°W / 70.0; -151.5
Approximate paleocoordinates	80°N 115°W
Region	Alaska
Country	United States

Age

The PCF ranges from Late Cretaceous (Campanian) to Paleogene in age. Due to a slight structural dip, the unit becomes progressively younger downriver (northward). Biostratigraphic analyses from the upper, vertebrate-bearing portion of the unit near Ocean Point indicate a temporal range from as old as late Campanian to as young as late Maastrichtian. Although previous radiometric dating suggested an early Maastrichtian age, more recent work indicates the fossiliferous beds near Ocean Point to be late Campanian in age (Druckenmiller et al. 2023).^[3]

Habitat

Hadrosaurids of the Liscomb Bonebed in their habitat

During the time when the Prince Creek Formation was deposited, Earth was going through a global cooling phase.^[4] The Prince Creek Formation depositional environment includes tidally influenced meandering rivers, anastomosed distributary channels, crevasse splays, levees, lakes, ponds, and mires.^[5] Large amounts of plants material are represented by peridonoid dinocysts, algae, fungal hyphae, fern and moss spores, projectates, Wodehouseia edmontonicola, bisaccate pollen, taxodiaceous pollen, and pollen from trees, shrubs, and herbs. Preserved woody trunks show trees did not exceed 20cm in diameter and canopy heights were estimated to have been around 5-6 meters tall. Frequent false rings observed in the dendrochronology of the stumps were deduced to have been caused by sudden drops in temperature during the growing season to between 6–10 °C (43–50 °F) suggestive of more sub-arctic summer conditions. These trees were compared to the modern Picea mariana which is common throughout the modern North American Taiga. Another similarity to modern boreal forests is the presence of charcoal indicating frequent forest fires in the depositional environment.^[6] Emerging methodologies using oxygen-18 isotope values from fossil vertebrate remains to estimate average meteoric water temperature have yielded highly accurate results. When applied to the Prince Creek Formation it estimated a mean annual temperature around 0 °C (32 °F).^[7] Mean annual precipitation was around 1,300 millimetres (51 in).^[8] The paleolatitude of the formation at the time of deposition was around 80°N, high in the Arctic Circle, and would have likely experienced 120 days of winter darkness.^[9][10]

Vertebrate paleofauna

Dinosaurs

Theropods

Indeterminate tyrannosaurid remains are present, mostly in the form of teeth. The teeth are from the Kikak-Tegoseak Quarry, Liscomb Quarry, and Byers Bed, totaling 8 teeth.^[11] Fossils of crown or near-crown birds as well as members of Hesperornithes and Ichthyornithes have been reported in 2025, providing the oldest evidence of birds nesting at polar latitudes reported to date.^[12]

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Theropods
Genus	Species	Location	Abundance	Notes	Images
Dromaeosaurus[11][13]	D. cf albertensis[11][13]	Liscomb Quarry[11] Kikak-Tegoseak Quarry[11] Byers Bed[11]	Fossilized teeth[11]	A dromaeosaur.
Ornithomimosauria indet.[14]	Indeterminate[14]	Old Bone Beach	Distal metatarsal IV	Possibly an ornithomimid.
Saurornitholestinae indet.[15]	Indeterminate	Pediomys Point - Liscomb Quarry[15]	Small dentary tip from a juvenile.[15]	A new species of dromaeosaurid closely related to Saurornitholestes.[15]
Nanuqsaurus[16]	N. hoglundi[16]	Kikak-Tegoseak Quarry[16]	One partial skull including a bone near the front of the maxilla and the front of the lower jaw.[16]	Nanuqsaurus is a tyrannosaurid closely related to Lythronax, Tyrannosaurus, and Tarbosaurus.[16]
Saurornitholestes[11][13]	S. cf. langstoni[11][13]	Old Bone Beach[11]	Teeth[11]	A dromaeosaur.
Troodon[16]	T. sp[16]	Kikak-Tegoseak Quarry[16] Liscomb Quarry[11] Byers Bed[11] Magical Mystery Bar[17]	Dental remains,[16] including teeth.[11] Braincases have also been found.[17]	Remains of T. sp. are approximately 50% larger than specimens from Alberta and Montana.[16] Remains were previously assigned to T. formosus.[13] The most abundant theropod.[17] As of 2011, a dubious genus.[18]

Ornithischians

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Ornithischians of the Prince Creek Formation
Genus	Species	Location	Abundance	Notes	Images
Alaskacephale[19]	A. gangloffi[19]	Kogosukruk Tongue[20]	A squamosal, and the back of the dome.[21]	The first pachycephalosaurine from Alaska discovered.[21]
Pachyrhinosaurus[22][23]	P. perotorum[22][23]	Kikak-Tegoseak Quarry[22]	An abundance of skeletal remains,[22] including an immature juvenile.[23]	The youngest of the Pachyrhinosaurus species, found in one of the highest latitudes of centrosaurine discoveries.[22] A discovery in the Kikak-Tegoseak Quarry was identified in 2013 as a juvenile of Pachyrhinosaurus perotorum. This discovery shows that the crest started to develop in the front of the snout, then extending farther back until it reaches the eye.[23]
Thescelosaurinae indet.[24]	Indeterminate		Teeth[24]	Remains previously attributed to Thescelosaurus.[24]
Leptoceratopsidae[9]	Indeterminate		Remains of adult and juvenile individuals[9]
Edmontosaurus[25]	E. cf. regalis[26]	Liscomb Bonebed[25] Kikak-Tegoseak Quarry[22]	Disassociated parts from multiple juveniles	Originally identified as a distinct genus (Ugrunaaluk), recent studies have found it ontogenetically indistinguishable from Edmontosaurus.[25][26]
Lambeosaurinae indet.[27]	Indeterminate	Liscomb Bonebed	A supraoccipital	The first confirmed lambeosaurine in the Prince Creek Formation.
Ornithopoda indet.[24]	Indeterminate[24]		One tooth[24]	A single "hypsilophodontid" cheek tooth not attributable to Parksosaurus or Thescelosaurus.[24]

Mammals

Mammals of the Prince Creek Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Cimolodon[28]	C. cf. nitidus		Lower Maastrichtian	Isolated teeth	A small multituberculate.
Gypsonictops[28]	G. sp.		Lower Maastrichtian	Isolated teeth	A small eutherian.
Multituberculata indet.[28]	Indeterminate		Lower Maastrichtian	Isolated teeth
Marsupialia indet.[28]	Indeterminate		Lower Maastrichtian	Most common in the Prince Creek Formation
Sikuomys[29]	S. mikros	Lower Colville River.	Upper Campanian		A tiny eutherian.
Unnuakomys[30]	U. hutchisoni	Pediomys Point	Lower Maastrichtian	Over 60 specimens	A small metatherian.

Cartilaginous fish

Cartilaginous fishes of the Prince Creek Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Squatina	S. sp.				An angelshark.[31]

Ray-finned fish

Ray-finned fishes of the Prince Creek Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Acipenseridae indet.					A sturgeon.[31]
Archaeosiilik[31]	A. gilmulli				A esocid salmoniform
?Beryciformes indet.					Acanthomorph remains reminiscent of beryciforms.[31]
Cypriniformes indet.[31]					A cypriniform, the oldest record of this order.[31]
Horseshoeichthys	H. armaserratus				An armigatid ellimmichthyiform.[31]
Neopterygii indet.					A potential basal neopterygian, known from a scale similar to Belonostomus.[31]
Nunikuluk[31]	N. gracilis				A esocid salmoniform
Oldmanesox	O. canadensis				An esocid salmoniform.[31]
Polyodontidae indet.					A paddlefish, potentially represented by two distinct forms.[31]
Sivulliusalmo[31]	S. alaskensis				A salmonid salmoniform, the oldest record of this family.

Plants

A Reinvestigation of the Parataxodium-type flora has revealed the assemblage was far more diverse than previously thought. However this sedimentary block’s stratigraphic origins are uncertain. No other in situ limestone blocks comparable to the Parataxodium-type flora have been located along the Colville River. Rivers upstream from the point of discovery cut through Upper Cretaceous deposits that range in age from Late Albian to Cenomanian. The diversity of flora present is more consistent with the Tuluvak Formation, which is dated to the Turonian-Coniacian.^[32]

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Plants of the Prince Creek Formation[33]
Genus	Species	Location	Abundance	Notes	Images
Parataxodium[20]	P. wigginsii[20]	Kogosukruk Tongue?[20]		Previously thought to represent a single taxon, now shown to have included many distinct conifer morphotypes.[20][32]
Oncophoraceae indet.		Kogosukruk Tongue?[32]		A Dicranalean moss.[32]
Osmundastrum[32]	O. cinnamomeum[32]	Kogosukruk Tongue?[32]
Ginkgo[32]	G. adiantoides[32]	Kogosukruk Tongue?[32]
Pityophyllum[32]	P. nordenskioldii[32]	Kogosukruk Tongue?[32]		Pinaceous needles.[32]
Sequioideae indet.		Kogosukruk Tongue?[32]		Previously included in Parataxodium.[32]
Taiwanioideae indet.		Kogosukruk Tongue?[32]		Previously included in Parataxodium.[32]
Cryptomerioideae indet.		Kogosukruk Tongue?[32]		Previously included in Parataxodium.[32]
Athrotaxoideae indet.		Kogosukruk Tongue?[32]		Previously included in Parataxodium.[32]
Archeampelos[32]	A. sp.	Kogosukruk Tongue?[32]
Cf. Cercidiphyllum	cf. C. sp.	Kogosukruk Tongue?[32]
Dicotyledon indet.	Morphotype 2	Kogosukruk Tongue?[32]
	Morphotype 3	Kogosukruk Tongue?[32]
	Morphotype 4	Kogosukruk Tongue?[32]
Monocotyledon indet.		Kogosukruk Tongue?[32]
Hollickia[20]	H. quercifolia[20]	Kogosukruk Tongue?[20]	Leaves[20]	An angiosperm, known from leaves.[20]
Quereuxia[20]	Q. angulata[20]	Kogosukruk Tongue?[20]		An aquatic angiosperm.[20]
Equisetites[20]	E. sp.[20]	Kogosukruk Tongue?[20]		A sphenophyte.[20]
Pulcheripollenites	P. krempii	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
cf. Proteacidites	cf. P. sp.	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
cf. Polycingulatisporites	cf. P. reduncus	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
Podocarpidites	P. sp.	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
Ovoidites	O.? sp.	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
	O. sp.	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
	O. parvus	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
	O. arcticus	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
Osmundacidites	O. wellmanii	Coleville River Bluff	Pollen remains	Common in the Early Maastrichtian. Also found in the Schrader Bluff Formation.
Mantonisporites	M. sp. indet.	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Mancicorpus	M. pseudosenonicus	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Lycopodiacidites	L. sp.	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Lunatadinium	L. dissolutum	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Indeterminate		Coleville River Bluff	Septate fungal hypha.	Also found in the Schrader Bluff Formation.
Leosphaeridia	L. "stellata"	Coleville River Bluff	Pollen remains	Common in the Early Maastrichtian. Also found in the Schrader Bluff Formation.
Lairidordites	L. magnus	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Laegivatosporites	L. sp.	Coleville River Bluff	Pollen remains	Indeterminate remains abundant in the Early Maastrichtian, and still numerous in the Late Maastrichtian. Also found in the Schrader Bluff Formation.
	L. sp.	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Kurtzipites	K. trispissatus	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Integricorpus	I. sp.	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Ischyosporites	I. sp.	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Inundatisporis	I. tappaniae	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Impardecispora	I. marylandensis	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Hannisporis	H. scollardensis	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
	H. amplus	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Gleicheniidites	G. senonicus	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Foveosporites	F sp.	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Foraminisporis	F. undulosus	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Fibulapollis	F. scabratus	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Expressipollis	cf. E. accuratus	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Erdtmannipollis	E. procumbentformis	Coleville River Bluff	Pollen spores	Also found in the Schrader Bluff Formation.
Dictyophyllidites	D. sp.	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Deltoidospora	D. sp.	Coleville River Bluff	Preserved pollen samples	Very abundant in the early Maastrichtian and Indeterminate level of the formation, becoming rarer until the Middle/Late Maastrichtian. Also found in the Schrader Bluff Formation.
Cycadopites	C. fragilis	Coleville River Bluff	Samples of distinct pollen	Also found in the Schrader Bluff Formation.
Crassispora?	cf. C. apisulacea	Coleville River Bluff	Pollen samples	Also found in the Schrader Bluff Formation.
cf. Converrucosisporites	cf. C. sp.	Coleville River Bluff	Specimens of preserved pollen spores	Also found in the Schrader Bluff Formation.
Clavatisporites	C. sp.	Coleville River Bluff	Preserved pollen samples	Also found in the Schrader Bluff Formation.
Circulodinium	C. sp.	Coleville River Bluff	Pollen samples	Also found in the Schrader Bluff Formation.
Cingutriletes	cf. C. congruens	Coleville River Bluff	Pollen remains	Also found in the Schrader Bluff Formation.
Cingulizonates	C. bialatus	Coleville River Bluff	Pollen samples	Also found in the Schrader Bluff Formation.
Cicatricosisporites	C. sp. 1	Coleville River Bluff	Distinct pollen remains	Also found in the Schrader Bluff Formation.
	C. sp. 2	Coleville River Bluff	Preserved pollen	Also found in the Schrader Bluff Formation.
	cf. C. dorogensis	Coleville River Bluff	Fossilized pollen spores	Also found in the Schrader Bluff Formation.
Cibotiumspora	C. sp.	Coleville Bluff Formation	Pollen spores	Also found in the Schrader Bluff Formation.
Camarozonosporites	C. ambigens	Coleville River Bluff	Pollen specimens	Also found in the Schrader Bluff Formation.
Botryococcus	B. braunii	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
Indeterminate		Coleville River Bluff	Bissacate gymnosperm pollen	Also found in the Schrader Bluff Formation.
Balmeisporites	B. sp.	Coleville River Bluff	Pollen spore remains	Also found in the Schrader Bluff Formation.
Azonia	cf. A. cribrata	Coleville River Bluff	Carbonized pollen	Also found in the Schrader Bluff Formation.
Aquilapollenites	A. trialatus	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
	A. sp. 2	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
	A. sp. 3	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
	cf. A. dentatus	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
	A. amygdaloides	Coleville River Bluff	Pollen	Numerous in the Late Campanian, becoming abundant in the Maastrichtian. Also found in the Schrader Bluff Formation.
Annulispora	A. sp.	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
Anacololsidites	A. sp. 1	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
	A. sp. 2	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
Alete	A. clavate	Coleville River Formation	Pollen	Also found in the Schrader Bluff Formation.
Aequitriradites	cf. A. spinulosus	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.
Aequitriradite	A. sp.	Coleville River Bluff	Pollen	Also found in the Schrader Bluff Formation.

See also

• List of dinosaur-bearing rock formations