The Prince Creek Formation is a geological formation in Alaska with strata dating to the Campanian and Maastrichtian stages of the Late Cretaceous and the Danian and Selandian stages of the Paleocene.Mull, G. G., Houseknecht, D. W., & Bird, K. J. (2003). Revised Cretaceous and Tertiary stratigraphic nomenclature in the Colville Basin, northern Alaska: US Geological Survey Professional Paper. Revised Cretaceous and Tertiary stratigraphic nomenclature in the Colville Basin, northern Alaska: US Geological Survey Professional Paper., 1673. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574-588. .
Age The PCF ranges from Late Cretaceous (Campanian) to Paleocene 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).
Habitat
During the time when the fossiliferous beds were deposited, Earth was going through a global cooling phase. The depositional environment included tidally influenced meandering rivers, anastomosed distributary channels, crevasse splays, levees, lakes, ponds, and mires. 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. False rings observed in the dendrochronology of the stumps were likely to have been caused by sudden drops below due to fluctuating summer temperatures, but other explanations are possible such as insect damage, flood and drought. Methodologies using oxygen-18 isotope values from fossil vertebrate to estimate average meteoric water temperature have estimated a mean air temperature of around for the north slope of Alaska. However there is a growing controversy about temperature estimates from stable isotope tracers during greenhouse conditions, their distributions do not align with the modern global meteoric water line making these results questionable. High but variable mean annual precipitation with low values of 350 to 1200mm/yr and high values of 1000 and 3900mm/yr suggests the presence of an intensified hydrological cycle which enhanced heat transport to the poles. This data supports the interpretation of greenhouse conditions in the Maastrichtian paleo-Arctic.
North of Oceans Point, a section of non-marine deposits represent moderately to poorly consolidated conglomerate, sand, gravelly-sand as well as pebbly shale with thin coal beds and lignitised logs. Many gravel clasts are composed of rock types which do not occur in the nearby parts of the Brooks Range, arguing against the source of local bedrock fragmentation. These clasts are as large as 1.2 meters in diameter with some bearing faceted surfaces characteristic of glacial transportation, though not by iceberg transport, as indicated by the non-marine deposition. These deposits are later assigned a Maastrichtian to lowermost Tertiary age, though recent radiometric revisions in age of older strata could suggest a slightly older age. Palynological assemblages here are characterised by a depauperate assemblage of Betulaceae, Myricaceae, Ulmaceae, Ericales, Pinaceae, Taxodiaceae, various Tracheophytes and Sphagnum. 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.
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. 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.
Theropods of the Prince Creek Formation Genus Species Location Abundance Notes ImagesDromaeosaurus"3.33 Alaska, United States; 3. Prince Creek Formation," in Weishampel, et al. (2004). Page 587.D. cf albertensisLiscomb Quarry
Kikak-Tegoseak Quarry
Byers BedFossilized teethA dromaeosaur.Ornithomimosauria indet.IndeterminateOld Bone BeachDistal metatarsal IVPossibly an ornithomimid.Saurornitholestinae indet.IndeterminatePediomys Point - Liscomb QuarrySmall dentary tip from a juvenile.A new species of dromaeosaurid closely related to Saurornitholestes.NanuqsaurusN. hoglundiKikak-Tegoseak QuarryOne partial skull including a bone near the front of the maxilla and the front of the lower jaw.Nanuqsaurus is a tyrannosaurid closely related to Lythronax, Tyrannosaurus, and Tarbosaurus.SaurornitholestesS. cf. langstoniOld Bone BeachTeethA dromaeosaur.TroodonT. spKikak-Tegoseak Quarry
Liscomb Quarry
Byers Bed
Magical Mystery BarDental remains, including teeth. Braincases have also been found.Remains of T. sp. are approximately 50% larger than specimens from Alberta and Montana. Remains were previously assigned to T. formosus. The most abundant theropod. As of 2011, a dubious genus.
Ornithischians
Ornithischians of the Prince Creek Formation Genus Species Location Abundance Notes ImagesAlaskacephaleA. gangloffiKogosukruk TongueA squamosal, and the back of the dome.The first pachycephalosaurine from Alaska discovered.PachyrhinosaurusP. perotorumKikak-Tegoseak QuarryAn abundance of skeletal remains, including an immature juvenile.The youngest of the Pachyrhinosaurus species, found in one of the highest latitudes of centrosaurine discoveries. 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.Thescelosaurinae indet.IndeterminateTeethRemains previously attributed to Thescelosaurus.LeptoceratopsidaeIndeterminateRemains of adult and juvenile individualsEdmontosaurusRe-examination of the cranial osteology of the Arctic Alaskan hadrosaurine with implications for its taxonomic status Ryuji Takasaki, Anthony R. Fiorillo, Ronald S. Tykoski, Yoshitsugu Kobayashi.E. cf. regalisLiscomb BonebedKikak-Tegoseak QuarryDisassociated parts from multiple juvenilesOriginally identified as a distinct genus (Ugrunaaluk), recent studies have found it ontogenetically indistinguishable from Edmontosaurus.Lambeosaurinae indet.IndeterminateLiscomb BonebedA supraoccipitalThe first confirmed lambeosaurine in the Prince Creek Formation.Ornithopoda indet.IndeterminateOne toothA single "hypsilophodontid" cheek tooth not attributable to Parksosaurus or Thescelosaurus.
Mammals Mammals of the Prince Creek FormationGenusSpeciesLocationStratigraphic positionAbundanceNotesImagesCamurodonC. borealisPediomys PointUpper CampanianIsolated teethA cimolomyid multituberculate.GypsonictopsG. sp.Lower MaastrichtianIsolated teethA small eutherian.KaniqsiqcosmodonK. polaris OJsaurus bone bedUpper CampanianIsolated teethA microcosmodontid multituberculate.Multituberculata indet.IndeterminateLower MaastrichtianIsolated teethMarsupialia indet.IndeterminateLower MaastrichtianMost common in the Prince Creek FormationQayaqgrukQ. peregrinusPediomys PointUpper CampanianIsolated teethA djadochtatheriid multituberculateSikuomysS. mikrosLower Colville River.Upper CampanianA tiny eutherian.UnnuakomysU. hutchisoniPediomys PointLower MaastrichtianOver 60 specimensA small metatherian.
Cartilaginous fish Cartilaginous fishes of the Prince Creek FormationGenusSpeciesLocationStratigraphic positionAbundanceNotesImages Squatina S. sp. An angelshark.
Ray-finned fish Ray-finned fishes of the Prince Creek FormationGenusSpeciesLocationStratigraphic positionAbundanceNotesImagesAcipenseridae indet.A sturgeon. Archaeosiilik A. gilmulli A esocid salmoniform?Beryciformes indet.Acanthomorph remains reminiscent of beryciforms.Cypriniformes indet.A cypriniform, the oldest record of this order.HorseshoeichthysH. armaserratusAn armigatid ellimmichthyiform.Neopterygii indet.A potential basal neopterygian, known from a scale similar to Belonostomus. Nunikuluk N. gracilis A esocid salmoniformOldmanesoxO. canadensisAn esocid salmoniform.Polyodontidae indet.A paddlefish, potentially represented by two distinct forms. Sivulliusalmo 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.