Dinosaur Park Formation

The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was laid down during the Campanian stage of the Late Cretaceous epoch between 76.9 and 75.8 million years ago. It was deposited in alluvial and coastal plain environments, and it is bounded by the nonmarine Oldman Formation below it and the marine Bearpaw Formation above it.AnodontosaurusA. inceptusAn ankylosaurine ankylosaurid.DyoplosaurusD. acutosquameusLower, 76.5Ma agoAn ankylosaurine ankylosaurid.EdmontoniaE. rugosidensLower, 76.5-75.9Ma agoA nodosaurine nodosaurid.EuoplocephalusE. tutusLower to Middle, ~76.4-75.6MaAn ankylosaurine ankylosaurid.PanoplosaurusP. mirusMiddle, 75.6Ma ago'Partial skeleton with complete skull, osteoderms, additional isolated teeth, postcranial elements, osteoderms.'A nodosaurine nodosaurid.PlatypeltaP. coombsiLower, 77.5-76.5 MAAn ankylosaurine ankylosauridScolosaurusS. cutleriLower, 76.5Ma ago or moreAn ankylosaurine ankylosaurid briefly thought to be synonymous with Euoplocephalus. It possibly came from the upper layers of the underlying Oldman Formation.S. thronusAn ankylosaurine ankylosaurid.CentrosaurusC. apertusMiddle, 76.2-75.5Ma ago' skulls, several skeletons, all adult; abundant bone-bed material with rare juveniles and subadults.' C. nasicornis may be a synonym.A centrosaurine ceratopsid.ChasmosaurusC. belliMiddle, 76-75.5Ma ago' skulls, several skeletons.'A chasmosaurine ceratopsid.C. russelliLower, 76.5-76Ma ago' complete or partial skulls.'MercuriceratopsM. geminiLower, ~77Ma ago'one apomorphic squamosal'A chasmosaurine ceratopsid.MonocloniusM. loweiA dubious centrosaurine ceratopsid.PentaceratopsP. aquiloniusUppermost, 74.8 MAtwo frill fragmentsA dubious chasmosaurine ceratopsid that may be the same species as Spiclypeus shipporum.SpinopsS. sternbergorumLower, 76.5Ma'partial parietal bone, partial dentary, unidentifiable limb fragments, partial skull, and partial right squamosal.'A centrosaurine ceratopsid.It may actually be from the upper Oldman Formation.StyracosaurusS. albertensisUpper, 75.5-75.2Ma ago' skulls, skeletons, additional material in bone beds.'A centrosaurine ceratopsid.UnescoceratopsU. koppelhusaePartial lower jawA leptoceratopsid thought to have been between one and two meters long and less than 91 kilograms. Its teeth were the roundest of all leptoceratopsids.VagaceratopsV. irvinensisUpper, 75Ma ago' skulls, skeleton lacking tail.'A chasmosaurine ceratopsid species previously classified as a species of Chasmosaurus.CorythosaurusC. casuariusLower-Middle, 76.5-75.5Ma ago'Approximately articulated skulls and associated postcrania, articulated skulls, isolated skull elements, juvenile to adult.'GryposaurusG. notabilisLower, 76.2-76Ma ago'Approximately complete skulls, fragmentary skulls, associated postcrania.'LambeosaurusL. lambeiUpper, 75.5-75Ma ago'Approximately articulated skulls with associated postcrania, articulated skulls, isolated skull elements, juvenile to adult.'L. magnicristatusUpper/Bearpaw Formation, 74.8Ma ago' complete skulls, one with associated, articulated postcrania.'ParasaurolophusP. walkeriLower, 76.5-75.3Ma ago'Complete skull and postcranial skeleton.'ProsaurolophusP. maximusUpper, 75.5 – 74.8 Ma' individuals, including at least articulated skulls and associated postcrania.'ForaminacephaleF. brevisFrontoparetal dome, various other skull fragments including juvenile and subadult materialOnce thought to be a species of StegocerasGravitholusG. albertae'Frontoparietal dome.'HanssuesiaH. sternbergiLower, also present in the Oldman Formation and Judith River FormationStegocerasS. validumSpecimens including frontoparietal dome.OrnithomimusO. sp.Type specimenAn ornithomimid, possibly a species of Struthiomimus.RativatesR. evadensType specimenAn ornithomimid, formerly a specimen of Struthiomimus.StruthiomimusS. altusType specimenAn ornithomimidCaenagnathusC. collinsiMandible, type specimenCaenagnathid ChirostenotesC. pergracilisSeveral fragmentary specimens, type specimenCaenagnathidsLeptorhynchosL. elegansSeveral fragmentary specimens, type specimenCaenagnathidsMacrophalangiaM. canadensisJunior synonym of Chirostenotes pergraciliscf. BaptornisIndeterminateA hesperornithine birdcf. CimolopteryxIndeterminatePartial coracoidA possible charadriiform birdDromaeosaurusD. albertensisSeveral specimens and teeth, type specimenA dromaeosauridHesperonychusH. elizabethaeHip bones and partial toes and claws, type specimenA microraptorine dromaeosaur, also found in the Oldman FormationLatenivenatrixL. mcmasteraeHip bones, pelvis, skull fragments, type specimenA troodontidcf. PalintropusUnnamedPartial shoulder girdlesAn ambiortiform bird.cf. Paronychodoncf. P. lacustrisTeethAn indeterminate maniraptoran, also found in the Judith RiverRichardoestesiaR. gilmoreiMandible, type specimenA dromaeosaurid.SaurornitholestesS. langstoniIncomplete skeleton and teeth, type specimen. A dentary referred to Saurornitholestes was discovered that preserved tooth marks left by a young tyrannosaur.A dromaeosauridStenonychosaurusS. inequalisNearly complete skeleton and other partial skeletons, type specimen.A troodontid once thought to be a species of TroodonDaspletosaurusUnnamed speciesMiddle-Upper, 75.6-75Ma agoSeveral specimensA tyrannosaurine tyrannosaurid, also present in the Bearpaw FormationGorgosaurusG. libratusLower-Middle, 76.6-75.1Ma agoNumerous specimens, type specimenAn albertosaurine tyrannosaurid The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was laid down during the Campanian stage of the Late Cretaceous epoch between 76.9 and 75.8 million years ago. It was deposited in alluvial and coastal plain environments, and it is bounded by the nonmarine Oldman Formation below it and the marine Bearpaw Formation above it. The Dinosaur Park Formation contains dense concentrations of dinosaur skeletons, both articulated and disarticulated, which are often found with preserved remains of soft tissues. Remains of other animals such as fish, turtles, and crocodilians, as well as plant remains, are also abundant. The formation has been named after Dinosaur Provincial Park, a UNESCO World Heritage Site where the formation is well exposed in the badlands that flank the Red Deer River. The Dinosaur Park Formation is composed of sediments that were derived from the erosion of the mountains to the west. It was deposited on an alluvial to coastal plain by river systems that flowed eastward and southeastward to the Bearpaw Sea, a large inland sea that was part of the Western Interior Seaway. That sea gradually inundated the adjacent coastal plain, depositing the marine shales of the Bearpaw Formation on top of the Dinosaur Park Formation. The Dinosaur Park Formation is about 70 metres (230 ft) thick at Dinosaur Park. The lower portion of the formation was laid down in fluvial channel environments and consists primarily of fine- to medium-grained, crossbedded sandstones. The upper portion, which was deposited in overbank and floodplain environments, consists primarily of massive to laminated, organic-rich mudstones with abundant root traces, and thin beds of bentonite. The Lethbridge Coal Zone, which consists of several seams of low-rank coal interbedded with mudstones and siltstones, marks the top of the formation. The sediments of the Dinosaur Park Formation are similar to those of the underlying Oldman Formation and they were originally included in that formation. The two formations are separated by a regional disconformity, however, and are distinguished by petrographic and sedimentologic differences. In addition, articulated skeletal remains and bonebeds are rare in the Oldman Formation but abundant in the Dinosaur Park Formation. The Dinosaur Park Formation can be divided into at least two distinct faunas. The lower part of the formation is characterized by the abundance of Corythosaurus and Centrosaurus. This group of species is replaced higher in the formation by a different ornithischian fauna characterized by the presence of Lambeosaurus and Styracosaurus. The appearance of several new, rare species of ornithischian at the very top of the formation may indicate that a third distinct fauna had replaced the second during the transition into younger, non-Dinosaur Park sediments, at the same time an inland sea transgresses onto land, but there are fewer remains here. An unnamed pachyrhinosaur, Vagaceratops irvinensis, and Lambeosaurus magnicristatus may be more common in this third fauna. The timeline below follows a synthesis presented by Fowler (2016) with additional information from Arbour et al. 2009, Evans et al. 2009, and Penkalski, 2013. Megaherbivore Assemblage Zones (MAZ) follow data presented by Mallon et al., 2012. Remains of the following amphibians have been found in the formation: Albanerpetontidae (extinct, salamander-like amphibians)