Dinosaur Hunter by Steve White

Author:Steve White
Language: eng
Format: epub
ISBN: 9781472812841
Publisher: Osprey Publishing
Published: 2015-11-11T16:00:00+00:00

DINOSAUR PARK FORMATION

Period: Late Cretaceous

Age: Mid-Campanian stage (77–74 mya)

Present location: North America

Reserve size: approx 3,400 square miles (a little smaller than Tsavo West National Park)

CONDITIONS

The Dinosaur Park Formation is found on the subcontinent of Laramidia. This narrow strip of land runs along a north–south axis and is rarely wider than 350 miles. It forms what is now the west coast of the North American continent, extending from the Arctic down to Mexico. At this time, a shallow ocean, the Western Interior Seaway, covered much of the interior and split the landmass into Laramidia to the west and an eastern subcontinent, Appalachia.

Temperatures at this time are cooler than earlier Mesozoic stages, but remain higher than modern pre-industrial times, warm enough to prevent glaciation at the poles and allowing ice to form only on the highest mountains. The general cooling was in part due to the lowering of carbon dioxide levels, to about two and a half times higher than present. This may reduce the mandatory need for use of rebreathers, but it remains strongly recommended they are deployed at all times.

GEOGRAPHY AND ENVIRONMENT

Dinosaur Park Reserve is situated roughly where Alberta, Canada is located. To its west is the Magmatic Arc of the early Rocky Mountain chain, at this time still relatively young and studded with a number of active volcanoes. The highest peaks are iced during the period of shorter days, which also precipitates a general cooling and the start of the wet season.

The Rockies also cast a rain shadow over their immediate foothills and the high plains to the east. These plains are several hundred feet above sea level and slope gently eastward. Large rivers running from the mountains form major watercourses which support riverine forests that thin to open woodland and ‘fruit prairies’ of juniper-like shrubs and ferns. Smaller watercourses desiccate in the dry season leaving soda lakes and restricting greenery to permanent rivers and the forests they support.

These woods and forests are largely angiosperms or flowering plants that have supplanted the evergreen gymnosperms of previous times. Pines, cycads and conifers are still present, but in much smaller numbers; the primary trees are the likes of sycamore, plane trees and maples. In the wet season, the profusion of fruit-bearing shrubs and fields of flowers such as the great carpets of goldfields that flower at the start of the rains, support huge herds of dinosaurs. Many of these ascend from the lowlands to breed on the high plains; huge nesting colonies of Hadrosaurs in particular can be found, formed from thousands of individuals.

The wet season also sees the soda lakes refill and attract nesting dinosaurs and flocks of pterosaurs and birds as the seasonal rivers return, fed by rain from the west of the Rockies and by meltwater from the higher peaks.

Beyond the rain shadow and the eastern edge of the high plains, the riverine forests thicken as the ground descends into lowlands. There is year-round rainfall and the temperature remains mild, turning the low flatlands into floodplains permeated with

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