Judith River Formation

Relationship with other units

The Judith River Formation conformably overlies the Claggett Formation and Pakowki Formation. It is overlain by the Bearpaw Formation. It is equivalent to the Belly River Formation in the southern Canadian Rockies foothills, the Lea Park Formation in central Alberta and the Wapiti Formation in the northwestern plains.

Sub-divisions

The Judith River Formation is divided into four members, the Parkman Sandstone Member, the McClelland Ferry Member, the Coal Ridge member, and the Woodhawk Member. The McClelland Ferry Member (78.7-76.3 Ma) is believed to be equivalent to the Oldman Formation, with the Coal Ridge Member (76.3-75.3 Ma) equivalent to the Dinosaur Park Formation.

Fauna

Faunal list follows a review published by Ashok Sahni in 1972 unless otherwise noted.

Amphibians

There are three potential species of discoglossid frogs. Hip bones, possibly representing a North American member of the European spadefoot toad family are also known from the formation.

Fish

Bony fish

Cartilaginous fish

Plesiosaurs

Pterosaurs

Choristoderes

Crocodylomorphs

Lizards

Ornithischians

Ankylosaurs

Hadrosaurs

Marginocephalians

Ceratopsians

Pachycephalosaurs

Theropods

Dromaeosaurs

Troodonts

Tyrannosaurs

Other theropods

Dubious Taxa

Many early American dinosaur discoveries were made in the Judith River Formation, and most of the early taxa are considered nomina dubia today.

Turtles

Flora

All the flora stated below is pulled from the PBDB.

Ferns

Gymnosperms

Cycadophyta

Conifers

Angiosperms