Milk River

Brachylophosaurus canadensis TMP 1990.104.0001, Oldman Formation, Milk River, Alberta. Original, not cast. At the Royal Tyrrell Museum of Palaeontology.

Brachylophosaurus canadensis TMP 1990.104.0001, Oldman Formation, Milk River, Alberta. Original, not cast. At the Royal Tyrrell Museum of Palaeontology.

Geographic and stratigraphic relationships of the holotype EMK 0012 and the Loki Quarry in northern Montana. (A) Regional relationships between the cross-border paleontological sites in the Oldman and Judith River formations along the Milk River and in Kennedy Coulee in Alberta and Montana. (B) Generalized stratigraphic section in the Kennedy Coulee area modified after Goodwin & Deino (1989) and Rogers, Eberth & Ramezani (2023) with the relationships between the Foremost and Oldman formations in Canada and the Judith River Formation in Montana. Relative placements of important taxa in this area are indicated. Position of 40Ar/39Ar dates originally obtained by Goodwin & Deino (1989) are shown in relation to the new U–Pb CA-ID-TIMS date for KC061517-1 by Ramezani et al. (2022). Bentonite ash beds are only 5 to 7 cm thick so they are exaggerated for clarity. Scale bars delineated in map view are indicated kilometers and in meters stratigraphically.

Brachylophosaurus canadensis skull (original). From the Oldman Formation, Milk River, Alberta. On display at the Royal Tyrrell Museum, Alberta, Canada.

Milk River (AB) Panoramic

Sandstones of the Milk River Formation flank the Milk river at Writing-on-Stone Provincial Park, Alberta.

World map showing Late Cretaceous metatherian locales. Europe 1. Font-de-Benon quarry, Archingeay-Les Nouillers (Cenomanian, Late Cretaceous), Charente-Maritime, southwestern France (Vullo et al. 2009) 2. Valkenburg Member, Maastricht Formation (late Maastrichtian, Late Cretaceous), southern Limburg, The Netherlands (Martin et al. 2005) Asia 3. Yixian Formation, China (Barremian, Early Cretaceous) 4. Bissekty Formation, Kyzylkum Desert, Uzbekistan (Turonian, Late Cretaceous) 5. Darbasa Formation, southern Kazakhstan (Campanian, Late Cretaceous) 6. Grey Mesa locality (Averianov 1997) 7. Barun Goyot Formation, Umuni Gobi, Mongolia (Campanian, Late Cretaceous) 8. Nemegt Formation, Omnogov, Mongolia (Maastrichtian, Late Cretaceous) 9. Djadokhta Formation, Mongolia (Campanian, Late Cretaceous) North America Alaska 9. Prince Creek Formation, Alaska (early Maastrichtian, Late Cretaceous) Alberta and Saskatchewan, Canada 10. Milk River Formation, southern Alberta, Canada (late Santonian, Late Cretaceous) 11. Oldman Formation, southern Alberta, Canada (Campanian, Late Cretaceous) 12. Dinosaur Park Formation, southern Alberta, Canada (late Campanian, Late Cretaceous) 13. Horseshoe Canyon Formation, southern Alberta, Canada (early Maastrichtian, Late Cretaceous) 14. St. Mary River Formation, Alberta and northwestern Montana (early Maastrichtian, Late Cretaceous) 15. Scollard Formation, Alberta (late Maastrichtian, Late Cretaceous) 16. Frenchman Formation, Saskatchewan (late Maastrichtian, Late Cretaceous) Montana and North Dakota 17. Judith River Formation (late Campanian, Late Cretaceous) 18. Two Medicine Formation (late Campanian, Late Cretaceous) 19. Hell Creek Formation, Montana and North Dakota (late Maastrichtian, Late Cretaceous) South Dakota 20. Fox Hills Formation, South Dakota (late Maastrichtian, Late Cretaceous) 21. Hell Creek Formation, South Dakota (late Maastrichtian, Late Cretaceous) Wyoming 22. “Mesa Verde Formation” (late Campanian, Late Cretaceous) 23. Lance Formation, Wyoming (late Maastrichtian, Late Cretaceous) 24. Ferris Formation, Wyoming (late Maastrichtian, Late Cretaceous) Utah 25. Cedar Mountain Formation (Albian-Cenomanian) 26. Dakota Formation fauna (late Cenomanian, Late Cretaceous) 27. Smoky Hollow Member, Straight Cliffs Formation (Turonian, Late Cretaceous) 28. John Henry Member, Straight Cliffs Formation (Coniacian-Santonian, Late Cretaceous) 29. Wahweap Formation (early-middle Campanian, Late Cretaceous) 30. Kaiparowits Formation (late Campanian, Late Cretaceous) 31. Iron Springs Formation fauna, southern Utah (Turonian – Santonian, Late Cretaceous) 32. North Horn Formation, Utah (late Maastrichtian, Late Cretaceous) Colorado 33. Williams Fork Formation, Colorado (late Campanian-early Maastrichtian) 34. Laramie Formation, northeastern Colorado (late Maastrichtian, Late Cretaceous) Baja California Del Norte, Mexico 35. El Gallo Formation (late Campanian, Late Cretaceous) (Clemens 1980; Lillegraven 1972; Lillegraven 1976) New Mexico 36. Fruitland and lower Kirtland Formation, San Juan Basin (late Campanian, Late Cretaceous) 37. Naashoibito Member, Kirtland Formation, New Mexico (late Maastrichtian, Late Cretaceous) Oklahoma 38. Antlers Formation, Texas and Oklahoma (Aptian-Albian, Early Cretaceous) Texas 39. Aguja Formation, West Texas (late Campanian, Late Cretaceous) New Jersey 40. Marshalltown Formation, New Jersey (Campanian, Late Cretaceous) Szalay 1994)

World map showing Late Cretaceous metatherian locales. Europe 1. Font-de-Benon quarry, Archingeay-Les Nouillers (Cenomanian, Late Cretaceous), Charente-Maritime, southwestern France (Vullo et al. 2009) 2. Valkenburg Member, Maastricht Formation (late Maastrichtian, Late Cretaceous), southern Limburg, The Netherlands (Martin et al. 2005) Asia 3. Yixian Formation, China (Barremian, Early Cretaceous) 4. Bissekty Formation, Kyzylkum Desert, Uzbekistan (Turonian, Late Cretaceous) 5. Darbasa Formation, southern Kazakhstan (Campanian, Late Cretaceous) 6. Grey Mesa locality (Averianov 1997) 7. Barun Goyot Formation, Umuni Gobi, Mongolia (Campanian, Late Cretaceous) 8. Nemegt Formation, Omnogov, Mongolia (Maastrichtian, Late Cretaceous) 9. Djadokhta Formation, Mongolia (Campanian, Late Cretaceous) North America Alaska 9. Prince Creek Formation, Alaska (early Maastrichtian, Late Cretaceous) Alberta and Saskatchewan, Canada 10. Milk River Formation, southern Alberta, Canada (late Santonian, Late Cretaceous) 11. Oldman Formation, southern Alberta, Canada (Campanian, Late Cretaceous) 12. Dinosaur Park Formation, southern Alberta, Canada (late Campanian, Late Cretaceous) 13. Horseshoe Canyon Formation, southern Alberta, Canada (early Maastrichtian, Late Cretaceous) 14. St. Mary River Formation, Alberta and northwestern Montana (early Maastrichtian, Late Cretaceous) 15. Scollard Formation, Alberta (late Maastrichtian, Late Cretaceous) 16. Frenchman Formation, Saskatchewan (late Maastrichtian, Late Cretaceous) Montana and North Dakota 17. Judith River Formation (late Campanian, Late Cretaceous) 18. Two Medicine Formation (late Campanian, Late Cretaceous) 19. Hell Creek Formation, Montana and North Dakota (late Maastrichtian, Late Cretaceous) South Dakota 20. Fox Hills Formation, South Dakota (late Maastrichtian, Late Cretaceous) 21. Hell Creek Formation, South Dakota (late Maastrichtian, Late Cretaceous) Wyoming 22. “Mesa Verde Formation” (late Campanian, Late Cretaceous) 23. Lance Formation, Wyoming (late Maastrichtian, Late Cretaceous) 24. Ferris Formation, Wyoming (late Maastrichtian, Late Cretaceous) Utah 25. Cedar Mountain Formation (Albian-Cenomanian) 26. Dakota Formation fauna (late Cenomanian, Late Cretaceous) 27. Smoky Hollow Member, Straight Cliffs Formation (Turonian, Late Cretaceous) 28. John Henry Member, Straight Cliffs Formation (Coniacian-Santonian, Late Cretaceous) 29. Wahweap Formation (early-middle Campanian, Late Cretaceous) 30. Kaiparowits Formation (late Campanian, Late Cretaceous) 31. Iron Springs Formation fauna, southern Utah (Turonian – Santonian, Late Cretaceous) 32. North Horn Formation, Utah (late Maastrichtian, Late Cretaceous) Colorado 33. Williams Fork Formation, Colorado (late Campanian-early Maastrichtian) 34. Laramie Formation, northeastern Colorado (late Maastrichtian, Late Cretaceous) Baja California Del Norte, Mexico 35. El Gallo Formation (late Campanian, Late Cretaceous) (Clemens 1980; Lillegraven 1972; Lillegraven 1976) New Mexico 36. Fruitland and lower Kirtland Formation, San Juan Basin (late Campanian, Late Cretaceous) 37. Naashoibito Member, Kirtland Formation, New Mexico (late Maastrichtian, Late Cretaceous) Oklahoma 38. Antlers Formation, Texas and Oklahoma (Aptian-Albian, Early Cretaceous) Texas 39. Aguja Formation, West Texas (late Campanian, Late Cretaceous) New Jersey 40. Marshalltown Formation, New Jersey (Campanian, Late Cretaceous) Szalay 1994)

Outcrops of the Foremost Formation along the Milk River.

Tooth of cf. Zapsalis, with close up of denticles. Specimen UALVP 49582 from the Milk River Formation.