Strolling tetrapod...

during the Devonian Period created a newly discovered trackway of great significance:

"The presence of footprints in rocks of this age is surprising: The tracks date to 18 million years before body fossils of tetrapods show up in the geological record.

...the findings “force a radical reassessment of the timing, ecology and environmental setting of the fish-tetrapod transition.” While previous studies have suggested that the first tetrapods hauled up on lakeshores or in freshwater deltas, these trackways hint that the water-to-land transition could have happened in a shallow marine setting."