Dinosaur Park Formation

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Dinosaur Park Formation
Stratigraphic range: Late Cretaceous, Campanian, 76.5–74.4 Ma
Dinosaur Park Formation exposed along the Red Deer River in Dinosaur Provincial Park, southeastern Alberta, Canada.
TypeGeological formation
Unit ofBelly River Group
UnderliesBearpaw Formation
OverliesOldman Formation
Lithology
PrimarySandstone (lower)
Mudstone and siltstone (upper)
OtherBentonite and coal
Location
Coordinates49°12′N 110°24′W / 49.2°N 110.4°W / 49.2; -110.4
Approximate paleocoordinates56°24′N 75°48′W / 56.4°N 75.8°W / 56.4; -75.8
RegionAlberta
CountryCanada
ExtentWestern Canadian Sedimentary Basin
Type section
Named forDinosaur Provincial Park
Named byEberth, D.A. and Hamblin, A.P.[1][2]
Year defined1993
Dinosaur Park Formation is located in Canada
Dinosaur Park Formation
Dinosaur Park Formation (Canada)
Dinosaur Park Formation is located in Alberta
Dinosaur Park Formation
Dinosaur Park Formation (Alberta)

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 deposited during the Campanian stage of the Late Cretaceous, between about 76.5 and 74.4 million years ago.[3] 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.[4]

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.[5] 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.[2]

The Dinosaur Park Formation has been a significant source of terrestrial vertebrate fossils for over a century. The first recorded account of fossils was in 1871 by the priest Jean-Baptiste L'Heureux who was shown bones of the "grandfather of the buffalo" by the Blackfoot Confederacy he was living with, though these notes were never published. Official reports of dinosaur bones in western Canada were reported by George Mercer Dawson in 1874 from southern Saskatchewan and Alberta along the Milk River. Further discoveries by Dawson and his colleagues of the Geological Survey of Canada continued in the 1880s, including the 1884 discovery by Joseph Burr Tyrrell of the skull of a theropod identified as Laelaps by American palaeontologist Edward Drinker Cope but named in 1905 as Albertosaurus by American palaeontologist Henry Fairfield Osborn. In 1889 rich fossil beds in the areas of Deadlodge Canyon[a] and Berry Creek[b] were found by Thomas Chesmer Weston along the Red Deer River. The areas along the Red Deer River would be more completely surveyed by Canadian palaeontologist Lawrence Lambe from 1897 until 1901, when he, along with Osborn, described the fossils found in what was then considered to be the Belly River Formation of mid-Cretaceous age.[6]

Geological setting

Restoration of the megafaunal dinosaurs of the Dinosaur Park Formation. From left to right: Chasmosaurus, Lambeosaurus, Styracosaurus, Scolosaurus, Prosaurolophus, Panoplosaurus, and a herd of Styracosaurus in the background

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.[4]

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.[4]

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.[2][4]

Biostratigraphy

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.[7] 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.[8][9]

Biostratigraphy of the megaherbivores of the Dinosaur Park Formation with ranges, assemblage zones, and radiometric dating after Mallon (2019) and Eberth and colleagues (2023):[10][11]

Lambeosaurus magnicristatusProsaurolophus maximusLambeosaurus lambeiCorythosaurus intermediusLambeosaurus clavinitialisParasaurolophus walkeriCorythosaurus casuariusGryposaurus notabilisAchelousaurusChasmosaurus irvinensisStyracosaurus albertensisChasmosaurus belliChasmosaurus canadensisChasmosaurusMercuriceratops geminiCentrosaurus apertusPanoplosaurus mirusDyoplosaurus acutosquameusEdmontonia rugosidensEuoplocephalus
Didymoceras cheyennenseExitelocerasDidymoceras stevensoniDidymoceras nebrascensisBaculites scotti

*The taxonomy of Euoplocephalus tutus is disputed, with Penalski (2018) separating the taxon into: Scolosaurus cutleri (~0m), Platypelta coombsi (~3-8m), Euoplocephalus tutus (~16-30m), Anodontosaurus inceptus (~27-31m), and Scolosaurus thronus (~40m)[12]

Paleofauna

Dinosaurs

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.
Size of the dinosaur megafauna of the lower Dinosaur Park Formation (the so-called "Centrosaurus-Corythosaurus zone")

Remains of the following dinosaurs have been found in the formation:[13][14]

Ornithischians

Remains of the following ornithischians have been found in the formation:[15]

Ankylosaurs

Numerous specimens that cannot be definitively assigned to ankylosaurs are known from the formation, including fragmentary cranial, dental, postcranial, and armour material.[16] As all ankylosaurids from the Campanian of Alberta and Montana were historically referred to Euoplocephalus sensu lato, the taxonomy is variable between studies and ranges from one to seven valid genera between the Dinosaur Park, Judith River, Two Medicine, and Horseshoe Canyon Formations.[12]

Ankylosaurs from the Dinosaur Park Formation
GenusSpeciesLocation[17]Stratigraphic positionMaterialNotesImages
Anodontosaurus[12] A. inceptus Hilda, Alberta[12] Middle DPF Two skulls, one with partial skeleton Previously considered specimens of Euoplocephalus but then referred to Anodontosaurus lambei, otherwise only known from the Horseshoe Canyon Formation,[16] before being given the new species A. inceptus.[12]
Dyoplosaurus[12][16] D. acutosquameus Q002 Lower DPF Partial skull and skeleton, two tail clubs Thought to be a synonym of Euoplocephalus for a time but separated as a distinct taxon.[12][16]
Edmontonia[18] E. rugosidens Q009, Q043, Q101, Q201, Q229, Q230 Lower DPF At least six partial skulls and skeletons A nodosaurid also known from the Two Medicine Formation
Euoplocephalus[12][16] E. tutus Q059, Q198 Lower to middle DPF Partial skulls and skeletons An ankylosaurid historically including all material from the formation. While some studies include up to 11 specimens even with Anodontosaurus, Dyoplosaurus and Scolosaurus separated, others limit it to 5 specimens and also separate Platypelta.[12][16]
Panoplosaurus[18] P. mirus Q008, Q228 Middle DPF Skulls and skeleton A nodosaurid 1/3 less common than Edmontonia.[17]
Platypelta[12] P. coombsi Q052 Lowermost DPF Skulls and skeletons Considered specimens of Euoplocephalus by some studies,[16] but separated as a distinct genus by others.[12]
Scolosaurus[12][16] S. cutleri Q080, Q089 Base of DPF Skull(s?) and skeletons Thought to be a synonym of Euoplocephalus for a time but separated as a distinct taxon.[12] Has been suggested to include Oohkotokia from the Two Medicine Formation, and also to be from the top of the Oldman Formation if the quarry is incorrectly mapped.[16]
S. thronus[12] Quarry No. 112[12] Upper DPF Skull and partial skeletons Considered indeterminate ankylosaurids or specimens of Euoplocephalus by some studies,[16] but separated as a distinct species by others.[12]
Ceratopsians

An unnamed Pachyrhinosaurus-like taxon has been recovered from the formation.[19]

Ceratopsians from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Centrosaurus C. apertus Middle, 76.2-75.5Ma ago[13] "[Fifteen] skulls, several skeletons, all adult; abundant bone-bed material with rare juveniles and subadults."[20][21] C. nasicornis may be a synonym. A centrosaurine ceratopsid
Chasmosaurus C. belli Middle, 76–75.5Ma ago[13] "[Twelve] skulls, several skeletons."[20] A chasmosaurine ceratopsid
C. sp. Lower, ~76.5Ma An unnamed chasmosaurine ceratopsid formally attributed to Chasmosaurus russeli
Cryptarcus C. russelli[22] Upper, 75-75.6Ma[22] A nearly complete skull. A chasmosaurine ceratopsid. Formerly assigned to Chasmosaurus.
Mercuriceratops M. gemini[23] Lower, ~77Ma ago[23] "one apomorphic squamosal"[23] A chasmosaurine ceratopsid
Monoclonius M. lowei A dubious centrosaurine ceratopsid. Synonymous with Centrosaurus.
Pentaceratops[24] P. aquilonius[24] Uppermost, 74.8 MA[24] two frill fragments[24] A dubious chasmosaurine ceratopsid that may be the same species as Spiclypeus shipporum.[25]
Spinops[26] S. sternbergorum[26] Lower, 76.5Ma[26] "partial parietal bone, partial dentary, unidentifiable limb fragments, partial skull, and partial right squamosal."[26] A centrosaurine ceratopsid. The holotype's locality is uncertain and may be from the upper Oldman Formation.[26] A parietal from Muddy Lake, Saskatchewan suggests they were present in the lower Dinosaur Park.[27]
Styracosaurus S. albertensis Upper, 75.5-75.2Ma ago[13] "[Two] skulls, [three] skeletons, additional material in bone beds."[20] A centrosaurine ceratopsid
Unescoceratops U. koppelhusae Partial lower jaw[28] A leptoceratopsid thought to have been between one and two meters long and less than 91 kilograms. Its teeth were the roundest of all leptoceratopsids.
Vagaceratops V. irvinensis Upper, 75Ma ago[13] "[Three] skulls, skeleton lacking tail."[29] A chasmosaurine ceratopsid species previously classified as a species of Chasmosaurus.[30]
Ornithopods

At least one indeterminate thescelosaurid specimen has been recovered from the formation.

In a 2001 review of hadrosaur eggshell and hatchling material from the Dinosaur Park Formation, Darren H. Tanke and M. K. Brett-Surman concluded that hadrosaurs nested in both the ancient upland and lowlands of the formation's depositional environment.[31] The upland nesting grounds may have been preferred by the less common hadrosaurs, like Brachylophosaurus or Parasaurolophus. However, the authors were unable to determine what specific factors shaped nesting ground choice in the formation's hadrosaurs. They suggested that behavior, diet, soil condition, and competition between dinosaur species all potentially influenced where hadrosaurs nested.[32]

Sub-centimeter fragments of pebbly-textured hadrosaur eggshell have been reported from the Dinosaur Park Formation. This eggshell is similar to the hadrosaur eggshell of Devil's Coulee in southern Alberta as well as that of the Two Medicine and Judith River Formations in Montana, United States.[33] While present, dinosaur eggshell is very rare in the Dinosaur Park Formation and is only found in two different microfossil sites.[31] These sites are distinguished by large numbers of pisidiid clams and other less common shelled invertebrates like unionid clams and snails. This association is not a coincidence as the invertebrate shells would have slowly dissolved and released enough basic calcium carbonate to protect the eggshells from naturally occurring acids that otherwise would have dissolved them and prevented fossilization.[33]

In contrast with eggshell fossils, the remains of very young hadrosaurs are actually somewhat common. Darren Tanke has observed that an experienced collector could actually discover multiple juvenile hadrosaur specimens in a single day. The most common remains of young hadrosaurs in the Dinosaur Park Formation are dentaries, bones from limbs and feet, as well as vertebral centra. The material showed little or none of the abrasion that would have resulted from transport, meaning the fossils were buried near their point of origin.[34] Bonebeds 23, 28, 47, and 50 are productive sources of young hadrosaur remains in the formation, especially bonebed 50. The bones of juvenile hadrosaurs and fossil eggshell fragments are not known to have preserved in association with each other, despite both being present in the formation.[35]

Ornithopods from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Corythosaurus C. casuarius Lower-Middle, 76.5-75.5Ma ago[13] "Approximately [ten] articulated skulls and associated postcrania, [ten to fifteen] articulated skulls, isolated skull elements, juvenile to adult."[36] A lambeosaurin lambeosaurine hadrosaur
Gryposaurus G. notabilis Lower, 76.2-76Ma ago[13] "Approximately [ten] complete skulls, [twelve] fragmentary skulls, associated postcrania."[37] A kritosaurin saurolophine hadrosaur
Lambeosaurus L. lambei Upper, 75.5-75Ma ago[13] "Approximately [seven] articulated skulls with associated postcrania, [possibly ten] articulated skulls, isolated skull elements, juvenile to adult."[38]
L. magnicristatus Upper/Bearpaw Formation, 74.8Ma ago[13] "[Two] complete skulls, one with associated, articulated postcrania."[38]
Parasaurolophus P. walkeri Lower, 76.5-75.3Ma ago[9] "Complete skull and postcranial skeleton."[38] A parasaurolophin lambeosaurine hadrosaur.
Prosaurolophus P. maximus Upper, 75.5 – 74.8 Ma "[Twenty to twenty-five] individuals, including at least [seven] articulated skulls and associated postcrania."[37] A saurolophin saurolophine hadrosaur.
Pachycephalosaurs
Pachycephalosaurs from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages

Foraminacephale

F. brevis

Also present in the Oldman Formation

Frontoparetal dome, various other skull fragments including juvenile and subadult material

Once thought to be a species of Stegoceras

Gravitholus

G. albertae

"Frontoparietal dome."[39]

Potentially synonymous with Stegoceras validum.[40]

Hanssuesia

H. sternbergi

Lower, also present in the Oldman Formation and Judith River Formation

Potentially synonymous with Stegoceras validum.[40]

Sphaerotholus

S. lyonsi[41]

Upper, 76.10 ± 0.5 Ma[41]

Right squamosal[41]

Stegoceras

S. validum

Specimens including frontoparietal dome.[39]

"Microcephale"

A nomen nudum.

Theropods

In the Dinosaur Park Formation, small theropods are rare due to the tendency of their thin-walled bones to be broken or poorly preserved.[42] Small bones of small theropods that were preyed upon by larger ones may have been swallowed whole and digested.[43] In this context, the discovery of a small theropod dinosaur with preserved tooth marks was especially valuable.[42] Possible indeterminate avimimid remains are known from the formation.

Ornithomimids
Ornithomimids from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Ornithomimus O. sp.[44] Type specimen An ornithomimid, possibly a species of Struthiomimus.[45]
Qiupalong Q. sp.[46] Several specimens An ornithomimid, possibly a radiation of this genus from Asia.[46]
Rativates R. evadens Type specimen An ornithomimid, formerly a specimen of Struthiomimus.[47]
Ornithomimosauria indet. Isolated material including unguals of the pes and the manus, caudal vertebrae, and a partial frontal[48] Indeterminate large Ornithomimosaur, material possibly similar to potential Deinocheirid material from the Judith River Formation.[49]
Oviraptorosaurs
Oviraptorosaurs from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Caenagnathus C. collinsi Mandible, type specimen A caenagnathid[50] which rivalled Anzu in size.[51]
Chirostenotes C. pergracilis Several fragmentary specimens, type specimen A mid-sized caenagnathid.
Citipes C. elegans[51] Several fragmentary specimens, type specimen Smallest caenagnathid from the formation.[51]
Macrophalangia M. canadensis Junior synonym of Chirostenotes pergracilis
Paravians

A new taxon of troodontid based solely on teeth is known from the upper part of the formation.[52]

Paravians from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
cf. Baptornis Indeterminate A hesperornithine bird
cf. Cimolopteryx Indeterminate Partial coracoid A possible charadriiform bird
Dromaeosaurus D. albertensis Several specimens and teeth, type specimen A dromaeosaurid
Hesperonychus H. elizabethae Hip bones and partial toes and claws, type specimen A dromaeosaurid or an avialan,[53][54] also found in the Oldman Formation
Latenivenatrix L. mcmasterae Hip bones, pelvis, skull fragments, type specimen A large troodontid measuring 3–3.5 m (9.8–11.5 ft).
cf. Palintropus Unnamed Partial shoulder girdles An ambiortiform bird
cf. Paronychodon cf. P. lacustris Teeth An indeterminate maniraptoran, also found in the Judith River
cf. Pectinodon[55] Indeterminate Teeth A troodont
Polyodontosaurus P. grandis Dentary, type specimen Nomen dubium. Possibly synonymous with Latenivenatrix.
Richardoestesia R. gilmorei Mandible, type specimen A dromaeosaurid
R. isosceles[52] Teeth
Saurornitholestes S. langstoni Incomplete skeleton and teeth, type specimen. A dentary referred to Saurornitholestes was discovered that preserved tooth marks left by a young tyrannosaur.[56] A dromaeosaurid
Stenonychosaurus S. inequalis Nearly complete skeleton and other partial skeletons, type specimen A troodontid once thought to be a species of Troodon
Tyrannosaurs
Tyrannosaurs from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Daspletosaurus D. horneri[57] Middle-Upper, ~75,6-75 Ma ago[13] CMN 350, partial skull and skeleton with left dentary (TMP 2010.121.0001) A tyrannosaurine tyrannosaurid, also present in the Two Medicine Formation.
D. wilsoni?[58] Middle-Upper, ~76,5-75,8 Ma ago[13] Several specimens A tyrannosaurine tyrannosaurid.
Gorgosaurus G. libratus Lower-Middle, 76.5–75 Ma ago[13] Numerous specimens, type specimen[59] An albertosaurine tyrannosaurid whose fossils have been unearthed in the Judith River Formation and possibly the Two Medicine Formation. It was the most common large carnivore in the area.[60]

Other reptiles

Choristoderes

Choristoderes, or champsosaurs, were aquatic reptiles. Small examples looked like lizards, while larger types were superficially similar to crocodilians. Remains of the following Choristoderes have been found in the formation:[61]

Crocodylians

Remains of the following Crocodylians have been found in the formation:[62]

Lizards

Remains of the following lizards have been found in the formation:[63]

Plesiosaurs

Remains of the following Plesiosaurs have been found in the formation:[64]

Plesiosaurs from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Fluvionectes F. sloanae A partial skeleton consists of a partial rib and gastralium, and left humerus, along with gastroliths An elasmosaur
Fluvionectes sloanae
Polycotylidae indeterminate

Pterosaurs

Remains of the following pterosaurs have been found in the formation:[65]

Pterosaurs from the Dinosaur Park Formation
GenusSpeciesLocation[17]Stratigraphic positionMaterialNotesImages
Cryodrakon [66] C. boreas Several large and small specimens consist of a partial skeleton An azhdarchid
Cryodrakon boreas
Pterosauria indet A indeterminate pterosaur

Turtles

Remains of the following turtles have been found in the formation:[67]

GenusSpeciesLocationStratigraphic positionNotesImages
Adocus
"Apalone"
Aspideretoides3 species
Basilemys A large Nanhsiungchelyid
Boremys
Judithemys
Neurankylus
Plesiobaena
TestudinataIndet

Mammals

Collection of theriiform mammals known from the Dinosaur Park Formation: Mesodma primaeva (top left), Alphadon halleyi (top right), Gypsonictops lewisi (bottom left) and an indeterminate therian, interpreted here as an hypothetical early placental (bottom right)

Remains of the following mammals have been found in the formation:[68]

Multituberculata

Multituberculatas from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Cimexomys C. sp.
Cimolodon C. spp.
Cimolomys C. clarki
Meniscoessus M. major
Mesodma M. primaeva

Metatherians

Marsupials from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Alphadon A. halleyi An alphadontidae marsupial
Eodelphis E. browni A stagodont metatherians
E. cutleri
"Pediomys" P. sp
P. sp
P. sp
P. sp
P. sp
Turgidodon T. russelli An alphadontidae marsupial
T. praesagus

Eutherians

Eutherians from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Cimolestes C. sp. A eutherian mammal with uncertain taxonomy
Gypsonictops G. lewisi A leptictidan mammal
Paranyctoides P sternbergi An early eutherian mammal

Fish

Remains of the following fish have been found in the formation:[69]

Amphibians

Remains of the following amphibians have been found in the formation:[79]

Amphibians from the Dinosaur Park Formation
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Albanerpeton A. gracilis A salamander-like Albanerpetontid amphibian
Habrosaurus H. prodilatus A salamander
Lisserpeton L. sp A salamander
Opisthotriton O. kayi A salamander
Scapherpeton S. tectum A salamander
Tyrrellbatrachus T. brinkmani[80] A frog
Hensonbatrachus H. kermiti[81] A frog

Invertebrates

Remains of the following invertebrates have been found in the formation:[82]

Flora

Plant body fossils

The following plant body fossils have been found in the formation:[84]

Palynomorphs

Palynomorphs are organic-walled microfossils, like spores, pollen, and algae. The following palynomorphs have been found in the formation:[85]

See also

Footnotes

References

Bibliography

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