After coming back from the USA, I got involved in Uhangri dinosaur footprint project in 1997. Two papers were published about the interpretation and mechanism of big manus-only sauropod tracks found in Uhangri Formation.
With support from the Cultural Heritage Administration, I explored southern coastal outcrops to find vertebrate fossils for three years. Through this project, a new pterosaur ichnotaxon was discovered from Hadong County and named a new ichnospecies, Pteraichnus koreanensis. It is a very tiny quadrupedal trackway, and its manus and pes length is less than 2 cm. It is one of the smallest pterosaur tracks in the world. Compared to abundant trace fossils, bony materials are scarce in Korea. With extensive surface prospecting, some bone materials were found in small islands and coastal areas of the Gyseongang Supergroup. They were all isolated teeth, but they clearly demonstrate a high diversity of dinosaur faunas. First, a tyrannosauroid premaxillary tooth shows that primitive tyrannosaurs lived in Korea, and several isolated theropod teeth also indicate that Acrocanthosaurus-sized meat-eaters existed. Besides dinosaurs, the first macrobanid turtle material was described from the Geoncheonri Formation, showing Kyrgyzstan's affinity. And a beautifully preserved crocodilian skull was also discovered from the Hasandong Formation. It is a primitive protosuchian crocodyliform, and the manuscript is about to submit.
Unexpected discoveries were dinosaur eggs and nests in many different localities. In the Hwaseong dinosaur egg site, approximately 200 dinosaur eggs with 29 clutches were found in 9 localities. They consist of three different types of eggs. One of them is obviously a new ootaxon because its size is only 9 cm in diameter, but eggshell thickness is over 5 mm and has very unique surface ornamentation. More interestingly, this site shows the site fidelity for the first time in Asia. The same kinds of eggs exist in 9 different horizons. It means that the same kind of dinosaurs visited this area many times to lay eggs. This fact makes Hwaseong dinosaur egg site unique in the world. So we need more detailed studies of the egg itself and the brooding behavior of this kind of dinosaur.
In 2008, a new dinosaur material was popped up from Hwaseong city. it was the first articulated dinosaur skeleton from Korea. Although the upper body was gone, hind limbs and tail were preserved in situ. This specimen turned out to be the first ceratopsian dinosaur in Korea and even a new genus. It was named as Koreaceratops hwaseongensis published in Naturweissenschaften. The interesting feature of Koreaceratops is its long caudal neural spines. That is, the tail is tall and flat laterally, implying a good swimmer. Also, its unique ankle bone shows that Koreaceratops was a good runner, too.