Middle Turonian dinosaur paleoenvironments in the Upper Cretaceous Kaskapau Formation, northeast British Columbia

Abstract

The Kaskapau Formation is a mudstone-dominated wedge up to 950 m thick that spans late Cenomanian to middle Turonian time. The formation has a prominent wedge geometry and was deposited in the foredeep of the Western Canada Foreland Basin. In outcrop in northeast British Columbia, nearshore sandstones are locally well developed and include rare wedges of nonmarine strata. On Quality Creek, near Tumbler Ridge, 11 m of nonmarine strata contain abundant dinosaur tracks and the first in situ dinosaur bone reported from British Columbia. This site, at a paleolatitude of about 67°N, preserves a rare glimpse of Turonian terrestrial environments during global eustatic highstand. Three main dinosaur habitats are recognized: strandplain and beach-ridge; freshwater lake; and brackish lagoon. Back-beach sandstone has a relief of about 2.5 m, interpreted as beach ridges; sandy coals containing abundant dinosaur tracks represent inter-ridge slough deposits. Overlying lake deposits comprising laminated muds with freshwater molluscs grade up into rooted muddy siltstone and locally, dinoturbated sandstone. Lake deposits are capped by lagoonal mudstone with abundant brackish-water molluscs, locally including a dinosaur-trampled oyster bioherm. The upper parts of sandy lagoonal deltas are pervasively dinoturbated. Sandstone filling a tidal channel contains logs, oyster shells, and bones of dinosaurs, turtles, and crocodiles, as well as fish scales. The lagoonal succession is erosively overlain by offshore sandy mudstones. Various lines of evidence suggest that the mean annual temperature at this sea-level location was about 14 °C, with a cold-month mean no less than 5.5 °C. The high-latitude location implies a significant period of winter darkness, and correspondingly diminished plant productivity.

Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs

“…Arbour & Currie (2013a) provided a comprehensive list of indeterminate ankylosaurid material collected from the Oldman, Dinosaur Park and Horseshoe Canyon formations of Alberta. Nodosaurid osteoderms have been reported from the Turonian Kaskapau Formation in British Columbia, but these await a full description (Rylaarsdam et al 2006).…”

Crocodylian Tracks from Lower Oligocene Flysch deposits of the Barail Group, Manipur, India

“…In North America, Cretaceous and Paleogene crocodylian fossils occur as far north as southern Alberta, Canada (Rylaarsdam et al, 2006), but the only modern representative is the American alligator (Alligator mississippiensis), whose range extends from North Carolina to Texas. Saltwater crocodiles (Crocodylus porosus) are endemic to coastal areas of the Indo-Pacific region, and the freshwater gharial (Gavialis gangeticus) inhabits rivers in northern India.…”

Vertebrate ichnites from the Boulder Creek Formation (Lower Cretaceous: middle to ?upper Albian) of northeastern British Columbia, with a description of a new avian ichnotaxon, Paxavipes babcockensis ichnogen. et isp. nov.

“…Space permits only a very brief summary of the main facies and depositional environments, based on results in Rylaarsdam et al (2006).…”