| Historically, the most influential and striking aspect of the geology at Blue Beach has been the discovery of vertebrate trackways from rocks that date from a time shortly after tetrapods first evolved onto land. As such, the section at Blue Beach is of international significance. Many trackways have been found at Horton Bluff over the years. In 1841, Sir William Logan (Fig. 5) was intrigued by building stone on the wharf at nearby Windsor. His inquiry about its origins led him to Horton Bluff, where he discovered a set of fossil footprints that we now know were made by an amphibian 350 million years ago. It was a radical discovery, for until then it was believed that fish were the only vertebrates present at the time represented by these rocks, |
Figure 5. Sir William Edmond
Logan (1798-1875. GSC(Atlantic).
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and that vertebrates did not come onto land until the Permian Period. Logan's discovery was the first evidence of life's early tentative steps onto land. When Logan displayed the tracks at a meeting of the prestigious Geological Society of London, his colleagues failed to acknowledge the importance of the find, holding on to the then current belief that fish were the only vertebrates in the Early Carboniferous.
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Figure 6. Sir William Dawson
(1820-1899). GSC(Atlantic).
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It was left to Sir William Dawson (Fig. 6) to vindicate Logan in his classic 1863 book, Air Breathers of the Coal Period. Dawson himself subsequently found footprints of both amphibians and reptiles at Joggins, Horton Bluff, and Windsor. He speculated that these "air breathers of the coal period ... haunted tidal flats and muddy shores, perhaps emerging from the water that they might bask in the sun, or possibly searching for food." Some of the track makers were probably small animals - certainly not as large as the animal that left the mysterious trackway discovered in 1964 (described in "Fossils at Blue Beach"), which may have been a primary predator. |
