You excavate a fossil of a small reptile during a paleontology field trip.It has the following characteristics: skull with a pair of dorsal temporal openings and a pair of lateral temporal openings; bipedal with legs positioned directly under the pelvic girdle.Dating with radioisotopes shows that the specimen lived 100 million year ago (MYA).You conclude that the specimen belongs to which reptilian group (be specific as possible)?

Question

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The fossil's characteristics, such as the skull with both dorsal and lateral temporal openings and bipedal posture, suggest it is a diapsid. However, the specific traits of bipedalism and the time period (100 MYA) align it more closely with dinosaurs, which are a subgroup of archosaurs within the diapsid lineage.

You Excavate a Fossil of a Small Reptile During a Paleontology