Final answer:
The rauisuchian fossils and petrified remains of a forest from the Triassic period in Canyonlands can be found in the a. Chinle Formation, which is renowned for its diverse fossil record and petrified wood.
Step-by-step explanation:
The student is inquiring about the geologic formation in which rauisuchian fossils and petrified remains of a forest can be found within the Triassic period at Canyonlands. The correct answer to this question is the a. Chinle Formation, which is known for its diverse array of fossils from the Triassic period, including petrified forests and ancient reptilian species such as the rauisuchians.
Other formations mentioned, such as the Cutler, Cedar Mesa, and Moenkopi, represent different geological periods or may not be as well known for Triassic fossils.
The Chinle Formation is particularly rich in petrified wood, which has turned into stone over millions of years due to the process of permineralization. This formation provides valuable insights into the ecology and climate of the Triassic period.