Theories abound as to how dinosaurs and other prehistoric creatures could have grown to such immense sizes, inconsistent with the spectrum of sizes for today's creatures and Earth's living conditions. Some focus directly on changes in the governing physics of the universe, such as a different gravitational constant. Some postulate that, rather than this difference, the earlier Earth experienced lower gravity due to differences in its size and mass. The majority focus on biological and aerodynamical anomalies that may have prevailed to explain these gargantuan sizes. This paper focuses on the latter group, offering an independent means by which to test the hypothesis that a (much) thicker atmosphere provided the buoyancy needed by these creatures to exist on land. This means is astronomical, an examination of possible differences in the rate of impact cratering on Earth due to atmospheric differences. With the Earth's atmosphere allegedly experiencing eras of much greater thickness than current, and alternating between these "thick" and "thin" atmospheric eras, it is postulated that, in addition to the biological and aerodynamical anomalies, a difference in the cratering rate from meteor impacts on Earth should be evident. Thicker atmosphere would "burn up" more meteors, reducing the cratering rate when compared to that during thinner atmospheric eras. This paper explores this, using the cratering rate from meteor impacts on the Moon as a "control" since it has no atmosphere to attenuate meteors but also is in Earth's orbital vicinity and should have experienced a nearly equivalent rate of meteor influx per unit surface area.
