A Cretaceous Lakeshore
The southern coast of Goseong shows the Early Cretaceous period, roughly 100-120 million years ago. The extensive gray rock beds exposed along the shoreline are part of the Jindong Formation, sedimentary layers that once formed the muddy floor of a large, shallow lake. This ancient environment proved to be a perfect medium for preserving the movements of the area's inhabitants. Over 4,000 individual dinosaur footprints have been identified here, forming more than 420 distinct trackways.
The sheer diversity of prints shows Goseong one of the world's most significant dinosaur track sites. The majority of tracks belong to ornithopods, herbivorous dinosaurs that often moved in herds. Their three-toed prints are found in numerous parallel trails, suggesting social behavior. Prints from carnivorous theropods are also abundant, showing long, narrow digit impressions ending in sharp claw marks. Adding to the complexity of this ancient ecosystem, the site also contains tracks of pterosaurs and some of the world's oldest known footprints of web-footed birds, indicating a diversification of shoreline avian species during this period.
Reading the Tracks
The Goseong coast is most famous for its sauropod tracks. These massive, long-necked herbivores left behind some of the most spectacular traces, including some pes (rear foot) prints over a meter long. At least three different sauropod species have been identified from the varied tracks in the area. One particular trackway, attributed to a sauropod of the Brontopodus ichnogenus, stretches for 84 meters, making it the longest continuous sauropod trackway discovered anywhere in the world.
These fossilized footprints offer evidence of presence and record behavior. Scientists analyze the depth of the prints, the length of the stride, and the spacing between the feet to estimate the animal's size, speed, and gait. For example, one sauropod species identified in the region, Gyeongsangsauropus pentadactylus, is estimated to have had a hip height of 2 to 2.9 meters with an average stride length of 150 cm. Some tracks are so exquisitely preserved that they show impressions of the dinosaur's skin. The site is actively studied, as the constant interaction of tides and coastal erosion continually exposes new layers and new footprints, offering more data from this Cretaceous world.